May
12

Car Air Conditioning System

By Jeff Williams

( Please click here  www.paypal.com/cgi-bin/webscr and make a small donation and I will answer any A/C question you have . Thanks Jeff )   Its that time of year again and for most of you Iam sure that you have already turned your vehicles A/C system to the  Max indicator on your dash.


For How To Charge Your Vehicles A/C System, Click On The Link To Watch The Video

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But what Iam sure of for most of you is, do you know how the system works and what to look for if its blowing out cool or even warm air.

So Iam here to give you a small class ( bare with me )  on just what makes the Car Air Conditioning System work in your vehicle. Then we will go over a few items to look for that will help you diagnoss your owns cars A/C sytem if its working under par.

OK, lets start with the basics. Your A/C system is a basic Heat Pump. It starts from the compressor as  low pressure  vapor and compressed into high pressure vapor. From there it is pushed through the  condenser where it becomes high pressure liquid by shedding heat  via the condenser.

After that it might pass through a drier (based on what system you have) where moisture is removed. From there it will pass through  a orifice valve or expansion valve based again on the type of system you have. The main reason for this is to slow the High pressure liquid down  to a low pressure liquid so it can evaporate better inside the evaporator.  As it evaporates from a liquid to a vapor it becomes very cold.


 
It then leaves the evaporator and passes through an accumulator and then heads back to the compressor as a low pressure vapor to start  the process  again. Depending on what system you have you will have a drier after the condenser or an accumulator after the evaporator .

The drier system will use an expansion valve set up, while the accumulator system will use an orifice valve set up

If the system is ever open, it is a good idea to replace them as they will become over saturated.

As far as freon, there are only  two types out there that most of you will come in contact with. They are the R-12 system and the more common 134A system. By 2011 though, car manufactures will start using R-1234 YF or even R-152A while European makers will switch to R-744


R-12 was banned in 1994 because of its effect on the ozone and thus R 134A took its place. R-12 molecules are much larger in shape than R-134A thus only tube and fin condensers were needed, but R-134A has much smaller molecules making heat transfer a little harder so engineers decided to come up with the parallel  flow condenser which has very small passages for the freon and oil to travel thus making flushing one after a compressor failure almost impossible.

Remember that if your mechanic trys to flush one out for you, then tell him you would rather have a new condenser installed.. Flush is good only up to a certain point but it should only be used on straight lines or tube a fin condensers, never parallel condensers or evaporators..

If you replace a condenser, remember that all condensers are not the same. Some shops will replace it with a cheap nock off to save a few bucks but you will feel it when it gets hot outside. Remember that the condensers job is to shed heat or better put it has to turn the freon vapor into a liquid by shedding BTUs of heat.

Its this low pressure liquid that travels to the evaporator were it is converted to a vapor by boiling into a vapor through the collection of BTUs of heat from inside your vehicle. This process  turns the evaporator ice cold .Air is blown over the ice cold evaporator and routed through the air ducts.

If your Nissan Quest had a condenser replaced and is now only blowing warm, chances are a cheap version of the OEM was installed. Demand an OEM replacement or you will never have cold air

Freon and oil travel together and they rely upon each other to help do there jobs so low freon means low oil movement and possibly trouble with the compressor. If you have a freon leak, look for signs of oil. That's the first give away and remember that all oils are not the same.


Another common place that leaks are the service ports. Most of the time they should have a plastic cap on them. If not then replace them with a new cap. Inside the service ports are small valve cores. The can leak and should be replaced if the system is opened. Also make sure you have a good seal inside your service port cap.

You will need one of these to remove the valve core. They are also great for tightening down your old ones if you suspect a leak there.

If your vehicle is running R-12 in it, then your Low side service port will look like this. ( Notice that it is threaded )

If you are running an R-134a system, then your Low side service port will look like this. The manufacturer does this for a reason so people cannot mistakenly mix freons in there vehicle


Most mechanics use either dye or an electronic sniffer to located leaks. Of the two I prefer the electronic sniffer from Yokogawa. Its fast and accurate and you don't have to wait for the dye to find its way out of the system before you try to find the leak.

Most freon leaks occur at the joints, seals and switches. The compressor body can leak as well and if the front shaft seal is leaking on a compressor its best to replace it completely.

R-12 uses Mineral oil while R-134a uses PAG ( Poly Alkaline Glycol ) and retrofits use Ester oil which will bind to both. Double end cap PAG will bond to both R-12 and R-134a.

ICE 32 is the Slick 50 of compressor lubricants and I highly recommend using it in every job but remember to subtract about 1.5 oz of oil to allow for its use.


Now what ever you do don't think that more is better when it comes to an A/C system In fact more is worse and can even destroy a system by creating excessive head pressure.

Freon is always introduced to an A/C system on the suction or low side. Do not try putting it into the High side or you will have some serious problems with your compressor not to mention the can or tank you are using might explode from excessive pressure from the compressor. You can spot the low side port by looking for a blue cap on the R-134a types. If the cap is black or you don't have a cap then you can find it by the large aluminum tank called the accumulator and it is smaller in diameter the the high side port and is always on the suction or low side line.


Oil is also introduced into the low or suction line. You can buy an oil injector at any after market A/C house or you can buy freon that has oil in it.


If you are the owner of an R-12 system then you will need a license to buy the freon as it was banned by the EPA. You can always convert or Retrofit your R-12 System but most of the conversions I have seen don't work very well and can be expensive to do if done the right way.

If you plan on putting freon in your own system then invest in a small kit at your local parts hose that comes with a small gauge that has a color chart along the pressure needle. Its a lot easier to check your own system with that then taking it to a shop.

Remember that too much freon is just as bad as not enough. If you over charge the system then you could damage the compressor, so don't think in this case that more is better. In most cases your A/C will blow warmer.

The only good way to check if you have a low freon charge is with a good set of gauges.

But you have to know how to read them and that will be another discussion.

If you have only warm air blowing out, check to see if the cooling fans and compressor clutch are coming on after you turn the A/C on. If  not then you will need to have it looked at by a qualified technician. ( Low freon will prevent the compressor from kicking on and a defective cooling fan could be at fault )

If you have no air coming out then chances are the fuse, relay or control head switch is defective. If you know your way around a Multi meter then you might be able to tackle this one yourself.

If only hot air ( And I mean hotter then outside ) is coming out then you might have a  stuck blend door .Check under the dash for lose or leaking vacuum lines ( Ford Cars and Trucks ) or the electric servo could be out. Always check fuses and relays first.

Most vehicles today use an orifice valve to control freon flow from a high pressure liquid to a low pressure liquid. They have built in screens to trap debris that is floating around. If yours is plugged up then you will get only cool are at best. The down side is that if it is plugged up tight , then the Head pressures in the compressor will go through the roof ( 500psi ) and unless you have a high pressure cut off switch then you will blow a compressor.


They come color coded so if you plan on changing out an orifice valve try matching it up by color. This is very important because the wrong size can play havoc with your system

Normal head pressure or high side pressure is calculated by multiplying the ambient temperature by 2.3. Suction or low side pressure should always be around 30 to 35 in hg.

Other systems use an expansion valve or H block as Chrysler calls it


Feel the lines before and after the orifice valve. ( It might take a little detective work to find it and not all cars have one ( ie. Saturn, Concord, New Yorker use the H Block ). If the line is  hot before and  cold after then your orifice valve is doing its job, but if the liquid line has frost on it then you have a problem.

If the line coming out of the evaporator is frosty cold then your system is working good but ifs its warm then you have a blockage or expansion valve problem.

If you have a fan clutch instead of electric fans, check for proper operation by warming the engine up to operating temp and then have someone watch the cooling fan as you turn off the engine. It should not keep turning after two seconds. With the engine off, check for any play in the fan clutch itself by try to move it up and down and side to side. Any lateral movement is not good.


If you engine is prone to over heating then your A/C system will suffer due to the fact that the condenser is already trying to shed heat from inside the car and having excessive heat next to it will make its job harder.

If your compressor is on its way out then you will hear it making a chattering noise when it is running. If it fails you must replace the condenser along with the compressor due to debris lodged in the condenser.

If your High pressure switch keeps shutting off you compressor then chances are you have a plugged condenser or your fans aren't kicking on.


Driers and accumulators are only good for a couple of years . 5 at max. The reason why is that one of there jobs is to remove moisture from the system because moisture is a non condensable and moisture plus R-134A equals Hydrochloric acid. Not good. After so long the dessicant bag becomes over saturated and can no longer do its job.


The primary job of either two is the separation of vapor and liquid freon. The drier prevents vapor from passing into the liquid line and the accumulator prevents liquid freon from  passing through the vapor line. I know it sounds a little confusing but try to think of it like this.

If any vapor leaves the condenser and makes its way to the evaporator then you loose that much cooling efficiency because vapor cannot collect heat and if any liquid is allowed to leave the evaporator that has not converted to a vapor then it will travel straight to the compressor and " Slug " or damage the compressor since liquid does not compress.


If your compressor fails then tell your mechanic that you want a new condenser and accumulator ( or drier ) valve cores, Double End Cap PAG oil with ICE 32 , in line filter, new orifice valve ( if you have one ) along with a new (not  a reman ) compressor. Trust me you will thank me next year.

Last but not least, never try to mix freons. It is a recipe for trouble.

There are a lot of people out there that will tell you that's its OK but here's the truth about it. Most commercial freons like R414b ( Hot Shot ) are made from a mixture of freons, one of them being R-22.


The R-22 is in not compatible with a mobile A/C system and will destroy compressor seals and O-rings in your system. You won't notice it now but by next year your system will leak from every seal if you use it.


The only legal Drop in I have seen is Freeze 12 but is does not work as well as R-12, so as long as its still available, use it.


Last but not least, don't mix R-12 with R134a. The two freons are not compatible with each other and in short you will have an expensive repair bill.

Now I know there is a lot that I didn't mention but I want you to have basics for this summer. I hope this has shed some light on how it works and what to look for and remember to look for this logo when you go to a shop. It means " Automotive Service of Excellence " and if the shop you visit does not employ these certified experts then maybe you should look else where.

 

Now remember that if you have question about your vehicles A/C system or a repair problem , then just leave a comment by clicking on the contact us tab at the top of the page and I will try to answer it on my next blog, and if this web site has been helpful to you then please click on the coffee cup icon below to help us keep this site running. Thanks for all your support.    Jeff

If you like this post, buy me a cup of coffee.

399 Comments

1

What will or could happen if you fill both the low and high side of ac with the R12A refrigerant, through the yellow hose without the car running?? and with the car running???

2

Hi John, That’s a good question . As long as the vehicle you are charging is Not running then you can charge on the High side without a problem. But if the vehicle is running and the compressor is cycling then DO NOT charge on the high side. The pressure from the compressor will travel back thru the lines and destroy your can or tank and quite possibly severely injure you in the process. Also remember to only run vapor in the low side. If you allow liquid to inter the compressor then you could ” Slug ” the compressor and damage the reed valves. If you’re not sure about something, send me a comment and I will get you an answer and if you have any other questions, please ask them and I will reply as quick as I can. Thanks for the comment. Jeff

3

My A/C hasn’t been working since last summer. I figure the freon is low. Yesterday smoke was coming out from under the hood and it looks like its coming from the compressor/clutch. Is this a simple fix of refilling the refrigerant? And will there be any damage to the compressor/clutch?

4

Hi Stephen 14. Well to start with there is one of two things that is causing this . Either you have oil seeping out of the front shaft seal behind the clutch and causing your clutch to slip or you are running under 11.8 volts to your clutch, also causing a slippage problem. Try turning the compressor by hand with the engine off. If it turns easily then look for signs of oil around the outer clutch pac. If no oil check your voltage with a multi meter. If you cant spin the compressor then it may be locked up and your clutch is trying to spin it. If the freon is low, you may have damaged the compressor due to over heating from a lack of oil that travels with the freon, either way you may have to replace the compressor. I recommend it over a clutch pac swap for a lot of reasons. Remember that an A/C system has to have a proper charge to deliver the oil in the system to the compressor. I hope this helps.

5

I charged my ac today and it was fine. I then got on the freeway, and it shut off while i was driving. can too much freon make your car shut off, and what should i do to fix it? someone told me that I could let some of the pressure out and i would be ok, and it wuld start is that true. I really need help!!

6

Hi Niki. I have never heard of too much freon shutting the engine off but I would like to know the make and model and year of the vehicle and I will get you an answer.

7

Hi Jeff – Great name by the way! Love your website and your knowledge of the Car A/C system is admirable.
I have just had to remove and replace the Condenser on my 2005 Mercedes W169 A Class due to pipe damage on the lower section, thanks to the friendly speed humps installed on my local roads around here!
I am actually a fully trained Commercial/Industrial Refrig engineer by trade, but my knowledge of the small car A/C system is limited. Whereas I know when and how much oil to fill in a larger commercial system with oil sight glasses etc to help, how much do I need to add to my car A/C system, where there are no sight glasses on the compressor to fill to?…and do I fill at the compressor, or charge into the suction side of the compressor maybe? Appreciate your help please. Jeff

8

This might be a little off topic, but does leaving your A/C on when you get out of your car do any damage to it?

9

Hi Jeff, Thanks for the feedback on our site. To answer your question, in most cases the condenser takes about an ounce of oil and should be added to a new condenser before its installed at the top of the inlet tube, since freon is always introduced at the top and leaves as a liquid at the bottom. I recommend Double end cap PAG oil.
Most of the time you can add oil on the suction line with out too much problem and remember to charge on the suction side, never on the high side unless you have an RRR machine and the engine is off.
I like to add oil on the high side but we use a machine to do it and the rule of thumb for oil on components is 1oz. for the condenser 1oz for the drier 1-2 oz for the accumulator 2-3 oz for the evaporator and 4 oz for the compressor, but make sure you check your capacities first. If you have questions about how to charge a system properly we are making a short video to help people do it themselves so stay posted. I hope that helps answer your questions and if you have more questions, feel free to ask. Take care Jeff

10

I would recommend shutting the A/C system off first before you shut off your car. It won’t damage anything if you shut off the car first but its easier on the system when you go to start it up ( ie the Battery ).

11

Jeff,
2000 Chevy Suburban (1500) with rear AC: I’ve had a horrible grinding noise coming from the compressor clutch area. After some investigation, it seems the AC drive belt tensioner is bottoming out, breaking of the nipple that’s supposed to keep it within its limits, and hitting a bolt holding the clutch on, breaking one belt and a brand new tensioner in the process. There is a TSB from GM for this problem, and the solution is to replace the compressor. I would accept this as the solution, but the compressor spins freely with no binding under no load conditions. Will it bind under a load only, or should I simply look at building manual tensioner instead? Thanks Jeff and wonderful website!

12

Hi Josh, The compressor shouldn’t bind under load but as head pressures climb there will be resistance on the compressor pulley. I would check the tensioner first before I replaced a compressor. If the spring is worn it will cause the tensioner arm to move past its max point. Also check out http://www.alldata.com if you haven’t already to find all TSBs on your Suburban. Maybe there’s more in there that you can use. Let me know if that helps. Jeff

13

2002 dodge intrepid. the ac was cool, but not cold. took it to a shop, they said freon was low and tightened a valve. ac is still cool. then they replaced the expansion valve and the drier. afterwards the compressor died so they replaced it. ac is still cool, not cold. now they say the next thing to replace to increase the coldness is the condensor. they also mentioned an evaporator but it is a much bigger job so they want to start with the condensor. isnt there a test where they can figure out if it is the evaporator before replacing a the condensor? im getting frustrated and loosing confidence. your thoughts and comments are much appreciated. thanks in advance

14

Hi Will, Sounds like the shop you are going to is trying to see how much money they can get from you. I am sorry but that happens a lot in the auto repair business. So to answer your question. If the compressor failed for any reason then I would replace the condenser. The reason why is that all the pieces of compressor that came apart where lodged in the condenser and no flushing in the world can get it out. I don’t recommend flushing but that’s another story. Yes there is a test to determine what or why your system was blowing only cool. Its a pressure test. They should have leak tested to find out where the freon was leaving the system. Electronic detectors are the best way and fastest. If you feel your liquid lines and suction lines as the system is working, then that will tell you a lot as well. If the compressor failed then chances are it was either ran with no or little oil or the head pressures shot up above 500 psi. I suggest that you get everything in writing and ask for a warranty . If the compressor failed and wasn’t loud or chattering before they worked on it then I would hold the shop accountable for it. Also get a second opinion if they say you need repairs done. If the shop you go to isn’t adding oil to the new components then the compressor will fail. Remember to ask if the mechanics are ASE certified and IMAC licensed for Automobile A/C. As far as your repairs are concerned, yes replace the condenser and you should have cold air. Don’t let them talk you into an evaporator as they rarely need replacing. Well I hope that helps you out and let me know how it turns out. Take care Jeff

15

I had a repair at Firestone because the car was smoking and the AC went from cold to very warm. They said it was a leaky hose and needed a new condenser and dryer. $725.00 total repair. After picking it up, the car made an awfule clattering noise but the AC worked for 2 days. Now 2 days there again is very warm air. Since it probably is a bad compressor and I’ve already replaced condenser, hose, dryer, will all those components have to be replaced again as a result of a bad diagnosis? And paid for a 2nd time?

16

Sorry, Jeff. I forgot to tell you that this is a 1998 Mazda Protege with about 150,000 miles. Pam

17

Hi Pamela, I have heard this before and it sounds like they might have forgotten to add oil to the new components, which would have run the compressor low or even dry which without proper lubricant would kill any compressor. The sad news is that anytime a compressor comes apart, the first place it dumps its guts is the condenser. Most condensers are parallel flow and cannot have metal flushed from them due to the very small passages in them. If your vehicle has a tube and fin condenser then I would say yes. For the repair have a new condenser with compressor and have them use Double End cap PAG oil along with Ice 32 . Small screens or inline filter will catch any debris that gets by and if it has an orifice valve then I would change that too. I know that sounds like a lot but its cheaper then replacing compressors every month. Let me know if that helps. Take care. Jeff

18

Hi Jeff. My 2003 Durango’s AC “chattered” for awhile then the air went hot. Mechanic put in new AC Compressor, recover and recharge ac system, drier, expansion valve and a belt. $950.00. Should I have had the condenser replaced also? Thanks!

19

Hi Mike. Yes I would ask for a new condenser as well ( Preferably an OEM because most after market condensers are less efficient then what the manufacturer specs call for ). Like I always say, anytime a compressor fails or locks up chances are that any bits and pieces of metal and teflon from the compressor will go straight to the condenser. Now Mike I believe that the Durango’s use a Piccalo condenser and they can be flushed out to some extent but with all the repairs that you had done on a 2003 , I personally would of had the condenser replaced as well. Remember its the condenser that converts the high pressure vapor to a high pressure liquid. If it cant do that or the efficiency is compromised in any way then so is your evaporators ability to become cold because it has less liquid freon to convert to a vapor which is what makes the evaporator cold. I hope this has helped Mike. Take Care Jeff

20

Hi Jeff, I have a 2005 Town and Country and just had the compressor fail. We replaced the Compressor but did not replace the condenser which is a parallel flow. It has been about a month since we replaced the compressor and now I have been reading about how you cannot flush our condenser. Should we go ahead and replace it now or is it to late?
Also, we had to have the evaporator replaced last year. Is it possible that when this was replaced that not being able to flush the system caused our compressor to fail?

21

Hi Jess, for starters I always recommend replacement of the condenser after a compressor failure. The drier or accumulator should also be replaced if the system is opened or over 5 years old along with the orifice valve. As far replacing it now, if you can afford it, this would be a good idea. Remember to get an OEM from the dealership. This is important because all condensers are not the same and saving a buck here will cost you later. I believe you have the dual zone system and you said you replaced the evaporator. If it was installed without oil or not enough oil then this will cause a compressor to fail. Evaporators take between 2 and 3 oz. of oil. Check with the shop that did the repairs. Last but not least, make sure the shop that is doing the repairs has techs that are ASE certified. Well I hope this has helped. Take Care. Jeff

22

I have a 2002 Dodge Durango that blows hot air up front and cold air in the rear. The lines are cold up to the firewall where the condenser is located. Dodge said it was an H-valve problem. Should the condenser be replaced as well? Thanks, April

23

Jeff, I have a toyota corolla 94 model. A/C is working fine. When the heat outside goes very high (Texas heat), the A/C blows hot air. Early morning and evenings it is pleasnat to drive. A/c works at that time. But around 4.00 it is difficult to sit inside the car. Freon level is ggod. It looks like the engine gets overheated and shuts the A/C during the summer time. I took the car to a local shop and they were not able to figure out anything. They ran the car for 30 minutes and told me everything looks good. Can you suggest me the areas where I need to look,. thanks for your help.

24

Hi April. I take it that you have a dual climate zone system with rear a/c. If the H block is not working right then the evaporator will not receive the proper amount of liquid freon. Now if the air that is blowing out is hotter then the ambient ( Outside ) air, then I would look at the blend doors not closing properly. If anything, remember to get a second opinion from a reputable shop before you decide on the repairs. While they have the system open, make sure they change out the drier. A simple pressure test with gauges will tell you if the condenser is plugged. I would only change the condenser if it needed it. A qualified ASE certified Tech should be able to make a good call on that. I hope that helps April and if you have more questions, just leave me a comment and I will get back to you as soon as possible. Take Care . Jeff P.S. Check out http://www.alldata.com for good info on your vehicle ( ie. TSBs ) .

25

Hi Pani. When a vehicle overheats, it effects the condenser ability to shed heat, so if your car is overheating I would figure out why. Check the cooling fans for proper operation and make sure they kick on when the A/C is turned on. Next, thermostat. If it is sticking closed, that will overheat an engine. Check the water pump belt for proper deflection. Make sure you are running 50/50on your anti freeze to water ratio. Make sure there are no obstructions in the front of the vehicle the are blocking air flow. Check the face of the condenser for any damaged or bent fins that will restrict air flow. Last but not least, check for coolant leaks that will cause low levels of engine coolant and thus cause overheating. I hope that helps Pani and if you have more questions, then leave me a comment and I will get back to you . Take Care. Jeff

27

Jeff, the air upfront is not warmer than the ambient air. It is only very slightly cooler. I had the system recharged earlier in the year and they told me they pulled a vaccum on the system, recharched it and added a dye to detect leaks because they said that the air should have been colder than what it was, could this have produced a problem? I will make sure that I ask the repair tech about the items you previously mentioned.

28

Hi April. I dont think the dye is affecting the performance of your A/C system . I don’t like using it because it takes to long to detect a leak and they make electronic detectors that are very efficient at pin pointing the leak on any system. Is the shop that you are going to using a Recovery/recharge machine?

29

Jeff,

What’s your opinion of Red Devil AC additive to plug a leak in the system? I have heard it’s one of the few that doesn’t clog the filters on the shop’s A/C recovery machines.

30

Hi Matt, I think you mean Red Angel, but yes Its a very good system sealer. We use TLC sealer and U-View sealer in the shop. They are great because they don’t clog the recovery machine’s and they don’t react with moisture. Thanks for the comment. Take care. Jeff

31

Yes, that’s the stuff, I think they make a “devil” product too that I mixed up, thanks for the comment!

32

My 94 Intrepid has a very slow Freon leak in the evaporator. A charge usually will last 5-6 weeks. The mechanic I go to for jobs I don’t want to tackle myself tells me that changing it is such a big and expensive job that until it gets worse just keep adding Freon. I bought a nice set of gauges and my father-in-law who is a retired professional mechanic tutored me on the system and how to charge it. I’m a pretty good mechanic but knew very little about a/c systems. I’m trying to find the low and high side pressures for this model. I’ve read most systems: Low side should read 25-40 while high side should read 225-250. BUT: Some Chrysler models the low side will be 15-25. Would you happen to know for sure what my gauges should read when I stop adding Freon? Thank you.

33

Hi Rick, Good question. The rule of thumb is 30-35 psi on the suction line and 2.3 times the ambient Temperature for the high side. For the exact pressures, you may have to call the dealership or go online to http://www.alldata.com. As far as your leak is concerned, you might be able to use a good quality sealer for that evaporator. If the leak is too big though you will have to change it out. I hope this has helped you. Take care. Jeff

34

Jeff,
Thanks for the fast response and info. I actually found the numbers just this afternoon of all places, in a Haynes auto a/c repair manual at an Autozone. It has a section showing the pressures for all makes and models up to 1999. I assume there is another book showing later models. For my 94 Intrepid it shows the low side 17-38 and high side 131-214. I’ve also read elsewhere 2.2-2.5 x the ambient temp so I think sticking with your 2.3 number would be more accurate than the pressure range the book shows.
I’m so glad I found your site as just reading other posts have answered many questions and concerns. I was very interested in finding out more about the leak sealers and it sounds as if you do believe in at least certain brands. Will these sealers not affect my gauges or later, my vacuum pump?
I have also been told that pulling a vacuum on the system does not remove the oil. I’ve not seen any evidence that it does and was told the only time I need to add oil is if components are changed. Is this true?
In my case where I have a very slow leak and will be adding probably a can every 5-6 weeks, do I at some point need to add oil as well?
Sorry for the question overload but you’re the best source out there.
Thanks for being there.

35

Hi Rick, I sent you a response to your e-mail address. I hope this helps you. Take care. Jeff

36

Thanks Jeff. You sure filled in a lot of gaps in what knowledge I did have. I’m confident now I can charge it on my own without blowing something up or killing the compressor. LOL.

37

2000 dodge intrepid after changeing parts could not get the compressor to cycle changed pressure switch. i have power to pressure switch but no power from pressure switch or power to the compressor… compressor was working fine before i changed parts….help please….michael

38

Hi Michael, the first thing I would do is use a jumper wire across the cycling switch connector to see if you can get the compressor to cycle. Also , make sure you have the proper amount of freon in your system. If you can cycle your compressor with a jumper then the problem might be in your control head. Also could you tell me what parts where changed out. Remember to always check fuses and relays first. Jeff

39

Jeff,
I replaced the expansion valve and the accumulator… the owner-(my neighbor) who owns the car, tried to do this work himself, before I worked on it released the pressure by opening the high side at the accumulator..this might be part of the problem. I wish he would have brought it to me first so I could have reclaimed the freon..I have tried to jump the pressure switch connector…still no results as far as the clutch kicking in. I have checked the fuse in the dash and checked the relays also to no avail. I know the compressor was working because I rode with him to town to get the parts.Thank You, Michael

40

This pressure switch connector is a three wire one is hot one is grounded and the third – I get nothing…. I jumped hot to ground and it kills the engine. I jumped hot to third wire and nothing.

41

A month ago, shortly after starting my car my clamp dropped off and hose blew off one end and all the freon in my car escaped in a cloud of steam. A friend who used to manage a shop replaced the hose and recharged the a/c. the a/c ran super cold air, the coldest I have ever had it and I have had my car for 9 years and I live in AZ. Now that the month has passed and we are at 115 outside the compressor froze up, I had a new compressor and kit put in at brakes plus this weekend and inquired about replacing the condensor, the owner said he would try to flush it first and if that didn’t work they would put in a new condensor. The flush worked so we did not end up buying the condensor. The shop replaced the serpentine belt as well while doing the work. My questions are 1. Did my friend put too much freon in and it took a month to damage the compressor? (I had a couple shops look at the compressor to verify it was bad, both said it had reddish brown stuff on it and the pully thing(?) would eventually give out because the belt couldn’t work properly even if I just stopped running the hot a/c that would not prevent a breakdown if the belt snapped as a result). Question 2. I have a 99 Dodge Stratus, would the flush really have worked like the shop said?

42

Jeff
I am in the process of replacing a compressor, drier and exp.tube. My question is. When I vacuum down the system after flushing and replacing parts do you add oil first? I have read where they state add oil to the compressor and rotate a few times. Does the vacuum process remove the added oil?
Thanks in advance.
Lynn Davis

43

Hi Candace. To answer your questions, I don’t think your friend over charged your vehicles a/c system because when you have to much freon in the system the air will not be that cols. I hope your friend added oil to your system due to the fact that when a hose breaks under pressure the freon comes out violently especially on the liquid lines and any oil that is traveling with the freon will be lost as well. As far as flushing is concerned, I don’t recommend it due to the fact that if any is left behind it will break down the oil and destroy the compressor and most condensers are of the parallel flow family which means no flush in the world will remove any pieces of compressor that are lodged in it . It sounds also like you snapped your serpentine belt, due to the compressor locking up. Make sure you get a Warranty on your repairs Also Candice, I’am sure the people at Brakes Plus did a good job but for future repairs I would try to find a shop that specializes in A/C and make sure they are ASE certified.. If you plan on getting the compressor replaced , then make sure its a new one ( OEM ) and not a re-manufactured on. You will thank me next year. Have the condenser replaced as well as the drier and ask for Ice 32 . If they know A/C then they will know what that is. And get a good warranty as well. I know that this might sound expensive but you will pay more by doing it wrong then by doing it right. I hope this has helped you Candace. Take Care. Jeff

44

Hi Lynn. For starters I would not flush the system . Unless you are flushing straight lines or a tube and fin condenser then I would not recommend it due to the fact that if any flush is left behind, it will break down the viscosity of the oil and destroy your compressor. As far as the drier and compressor go, the rule of thumb is 1 oz for the drier , 4 oz for the compressor. Its always safe to drain out the oil that was shipped with the compressor and add your own. Try to use a Double End Cap PAG oil and if you can find it also try ICE 32 but remember to adjust your oil amount to account for the Ice 32 if you use it. Ice 32 is an oil additive and will prolong the life of the compressor. Think of it as Slick 50 for A/C systems. You are right about turning the compressor by hand a couple of turns to circulate the oil so as to not damage it upon initial start up. If you are replacing components then add the oil to each of the components before installing, then after the system is put back together that’s when to pull a vacuum. Pulling a vacuum does not remove any oil. I hope this has answered some of your questions Lynn. Take Care Jeff

45

Interesting and helpful info. I do have a concern I hope someone can help me with. First, I own a 1996 Chevy Lumina. I ended up replacing the compressor a little over 3 years ago and all is fine. I just relaced the altenator a week ago and volts are good on battery & altenator and car ran fine with A/C on. Started the car a few days later and issues came. The problem is this, low/rough idle and when the A/C is turned on (fan also starts), it engages rough and then the car runs rough. I would assume the compressor is fine because cold air comes out. A mechanic suggested I should just chnage the A/C clutch. Question-could this be a sign the clutch is bad or the compressor?? Any suggestions??

46

Hi Amy, I don’t think that your clutch pack is bad or even your compressor. I would have the voltage tested again under load to see if you are producing enough voltage. Also check the battery’s state of charge to make sure it is in good condition. I hope this helps Amy. Take care Jeff

47

Thank you Jeff!! I will get the battery and altenator voltage checked again (while I just replaced the battery a couple months ago too). I am so frustrated because I do not want to run the A/C and brake down (In FL, it feels like 110 degrees)I am not too sure on where to go from here as when ever I turn on the A/C, it makes a ringing sound but only when the A/C is on. That is why I thought it would be the clutch. I am not too sure why my idle if off/rough everytime I turn on the A/C? When this happened to me, it also triggered the EGR (low air flow) sensor, which tells me something is off. Any suggestions as to where to go from here after the voltage is checked again??

48

Hi Amy, I sent you an E- mail with additional info for your problem. I hope it helps. Take Care Jeff

49

Hi, my 2005 Kia Optima air strted gradually getting warmer so I serviced it with R134 and it stayed cool for only a couple of days then got hot again. I’ve looked at all of the exposed fittings and condeser for telltale signs of oil, but no joy there. Doeas anyone rent sniffers or will I have to cave in and take it to a mech? I’m an A&P mech, and have installed A/C systems in acft., but it was many yrs ago, and I don’t have any of the equipment left. Does r134 require a different sniffer from r12? It seems counterintuitive, but could it be someting other than a leak considering adding r134 fixed it briefly?

50

Hi David, as far as sniffers for rent, I would probably say no. I would choose an electronic sniffer over dye injection any day of the week so if you go this route choose the sniffer. You can buy one for about $ 150.00 from Robinair . Most sniffers on the market today are designed to detect all CFC, HFC, and HCFC Refrigerants, which include R-134a, R-12, R-22 and so on. The first thing you should do is a pressure test to find out if the system is properly charged. Then if not , a leak detector would be the next step, but remember you must have at least one pound of freon in the system to perform a good leak test. I hope this helps David. Take Care Jeff

51

Hi Jeff,

I just charged my system on a 2004 nissan xterra my pressures were 55 on low and 250 on high this is in arizona temp about 100 F and I had just replaced the compressor I was expect low side to be around 30 to 40 is 55 acceptable also the can fell over and I believe some liquid got in the low side do you think that could be my cause for the higher reading on the low side Thanks jeff

52

Hi Stefani, Those pressures sound a little high. I need to know what your duct temp was. ( duct closest to the evaporator ). Make sure you put the right amount in. Too much is just as bad as to little. There should be a yellow label in the engine compartment telling you the exact factory charge. Its important to be close to that number. As far as the liquid freon is concerned, I think you will be all right as long as not too much liquid traveled to the compressor which would damage a reed valve. Remember liquid does not compress. I don’t think that’s causing your higher numbers. Was the system empty first or did you try to top off the system and if the system was empty did you pull a vacuum first before charging ? Let me know. Take Care Stefani. Jeff

53

Thanks for the response Jeff, duct temp was around 38 degrees (f) I charged the system with 24 oz system calls for 21 to 24 oz although when the job was done and I went to clear out my gauge set there seemed to be alot of gas in high side line; I did pull a vacuum for about 30 minutes on a 2 stage 3 cfm pump: yes the system was empty I had just replaced the compressor thanks jeff by the way the system seems fine I am inquring because I want to make sure I do everything as ell as possible

54

Hi Stefani, yes you will always see a lot of liquid left over in your high side line when you go to clear it out. Nothing to worry about. I was wondering though why you decided to change the compressor and did it come shipped with oil or did you put your own in? I ask about the compressor because if you had a compressor failure then I would probably say that the condenser might have pieces of compressor still in it. Also while I had the system open I would change out the drier ( accumulator ) . Double End Cap PAG oil is also the best to use along with Ice 32. I hope this helps you Stefani. Jeff

55

Thanks for quick response I Changed the compressor because there was no movement in pressures with clutch engaged readings were only ambient of outside pressures, compressor did come shipped with (ICE) oil I turned the old compressor upside down and turned the shaft shook it to make sure everything was out then measured how much oil can out then replaced it with pag 100 oil to that same amount thanks your responses do help also when you replace the drier are you adding basic .7 oz of oil to the drier itself or entering through the system. thanks jeff I appreciate all your help

56

O k new vechicle new problem this guy has had no a/c for 3 years two shops told him compressor was bad he wanted me to change it so I did this is a toyota land crusier 93 withR134 I changed the compressor, drier, and expansion valve pulled vacuum and charged with 34 oz which is what the truck calls for had a hard time geeting freon in and it seemed to stop cooling towards the last 10 oz can;t be an overcharge system was empty, Iam thinking cologged condensor can you come up with something better or something that may shed some light on my sitituation thanks jeff please help not sure where to go if it not the condensor and I want to make sure that is the problem I just don’t want to change parts hoping it will fix it

57

Hi Jeff , you should add about an oz to the drier itself if you are replacing it. I have noticed that some systems operate better if you add the oil to the system not in the drier but that is my opinion. Jeff

58

Hi Jeff. Anytime a compressor goes bad and the condenser is not of the tube and fin design then I always recommend replacing it. Also I noticed you are using 12 oz cans to charge the system. If you can afford it I would highly recommend using a high quality scale and a 30lb tank. Its much more accurate and less chance of liquid getting in. Jeff

59

Hi Jeff. I have a 93 full size blazer that i’m fixn to replace the compressor, accumulator, condensor, and orifice tube. My system uses 8oz of PAG150. How do I split that up? The compressor came empty and they gave me an 8oz. bottle of PAG 150 refrigerant oil with ice 32 and also talked me into a couple cans(2) to start charging my system called 1st Charge with ice 32, contents: 11oz R134a, 1oz ICE32, and .5oz drying agent. Would I subtract 2oz of oil, or less, for maybe some being lost in hoses or the oz. that you lose per can when charging the system? Would an oz. over hurt? Just one more question should I use in line filter screens in my system?

60

Jeff,
Thanks for providing such great information. I have a 97 VW Jetta GLX VR6 engine. AC has been running warm as of late, so checked my pressures. All measurement below with car fully warmed up, at idle (750 rpm), AC on HIGH, all windows open. An Orlando, FL muggy evening.

Before @85 deg ambient LOW: 27 HIGH: 105 Discharge Air temp 60 deg

After charge @85 deg ambient LOW: 30 HIGH: 195 Discharge Air temp 44 deg

With the engine rev to 1500, LOW drops to 25, HIGH remains fairly constant.

Just want to run these buy you and get some feedback. I “think” the system is charged about right? Though the LOW seems a little low, need to check the VW manual. Your thoughts?

61

Hi Tim, It sounds like you are doing it right. As far as the numbers are concerned, put all the Ice 32 in the accumulator and subtract two oz from the total. Accumulators take about 2 oz of oil. The Condenser about 1 oz of oil and the compressor about 4 oz of oil. The evaporator hols between 2 and 3 oz of oil. Make sure to rotate your compressor a few turns by hand before you install it. In a system that big an extra oz of oil should not hurt. In line filters are great to use especially if you blew a compressor. We use the ones the fit in the back of the compressor but they are making some universal ones that you can see the filter element. When you evacuate try about 30 minutes and don’t forget to change out the service ports while you have the system open. Make sure all of you lines are in good shape. If you suspect a bad rubber line then replace it. That should about cover it Tim. I hope that helps and if you have more questions, I would like to hear them. Take Care Jeff

62

Hi Mike. Those numbers sound ok. Did you try a top off or did you evacuate and recharge with the exact amount of freon. I would also leak test the system with a sniffer if you can get one. Freon doesn’t evaporate. It finds a place to leak out of so if your system was low chances are that you might have a small leak. If so try to find the leak and repair it if not then try a good sealer. I also recommend using an electronic scale to weigh your freon instead of trying to figure it out with the small cans. Well I hope this helps Mike. Take Care Jeff

63

Appreciate the quick feedback Jeff. No, I did not evacuate the system and recharge from scratch. That would have been my preferred method, as I could weight the charge and get it exact, but I do not own a vacuum pump, and I was looking for a quick fix. Florida in the summer, ya know?? I am the classic “do it yourselfer”, and typicaly borrow or rent a pump when I need it.

I am preparing myself for the fact that there is probably a small leak somewhere in the system. Will monitor the temperature and see how long the charge holds. There is already dye in the system and I have a UV light, unless the leak is really small or in a place I cant see with the light. There is an AC place down the street from my house that has “sniffed” my car in the past for a leak and they never charge me (Ice Cold Air, HWY 50, downtown Orlando).

I have become quite intimate with the entire dashboard / center console / airbag / instrument cluster / radio removal process, and can almost do it with my eyes closed (all of which is necessary to get to the evaporator). Gotta love German engineering. The dealer charges an ungodly amount of money (labor hours) to replace the evaporator because of the dash remove / install effort.

My VW has been a chronic AC nightmare. I am the original owner (12+ years), and so far I have personally performed the following repairs:
Year 3 – Condensor (leak, replaced with factory part $$$), receiver/dryer
Year 5 – Evaporator (leak, replaced with factory part $$$), expansion valve, receiver/dryer
Year 7 – Compressor (started to loose suction but didn’t fail, New OEM replacement), expansion valve, receiver/dryer
Year 9 – Evaporator (leak, replaced with after market part supposed “better design), expansion valve, receiver/dryer
Year 12 – Tho not an AC problem specifically, HEATER CORE blow out, which requires removal of entire evaporator core / air box… so replaced receiver dryer, new o-rings for expansion valve

After all this “experience”, and the fact I own just about every other HVAC tool, I am seriously considering PURCHASING a vacuum pump. Do you have any suggestions for types / brands. I would like to keep it under $350 as I will not be using this as a professional. I am guessing a 2 stage, but not sure if I should go with a lower 3 CFM or is the 5-6 CFM worth it?

64

Hi Mike. Wow, that sounds like a lot A/C repairs on your VW. As far as vacuum pumps go I would recommend a Robinair 2 stage 6 cfm pump ( part number 15600 ). You can find them for under $ 300.00 dollars at places like http://www.thetoolwarehouse.net/ . I have purchased through these people before and you can trust them. I use the Robinair pump all the time and as long as you change out the oil every so often, then it works great. Well I hope that has helped answer some of your questions Mike, keep the comment coming and try to stay cool this summer. Take Care. Jeff

65

Hey Jeff,
I have a 2006 Dodge durango with dual air. The air in the front has been coming on and off for a while when turned on . The rear is still blowing when turned on . Recently the front has not been working but the rear still works and is blowing cold. Any suggestions.

66

Hi Michael, You might want to check the resistor block for the front motor. If there is a problem there then the blower motor may not work on certain speeds. Also the control head may have a short in it causing an intermittent problem with the blower motor. When you say that the front air is coming on and off , I would think that you are talking about the blower motor itself. Also check the relays for the blower motor as well. I have seen some that are not working all the time . Last is the blower motor itself. If it has a short in it that could cause it not to work as well . I hope this helps. Take care Jeff

67

do you have any ideas what would cause hi pressure switch to be blown completly out of the compressor on a 2000 chevy Astro.

68

Hi John, If you are talking about the thermal limit switch on the back end of the compressor, I would say one of two things might have happened. One, your head pressures went so high it blew out the switch or the snap ring that holds it in came loose somehow allowing it to come out. I hope this helps John. Take care Jeff

69

Jeff, thank you for your quick response to my a/c question. A plugged orfice tube would be the only possible reason for the high pressure,right? Also, the best scanner and software for around $200?

70

Hi John, You will know once you pull it. There are other factors that will cause high head pressure ( ie. plugged or restricted condenser, restricted air flow, inoperative cooling fans, over charged system, ect. ) As far as scan tools under $ 200.00 check out Actron, EZ scan from Auto X Ray , and Equus http://www.thetoolwarehouse.net/p-1126-equus-3130.aspx. They are all good for the price. I hope this helps John. Jeff

71

i have a 97 chevy blazer and the Accumulator Drier has condensation on it the air is not running at all its enough that it is dripping off the bottom of the accumualter drier what could cause this problem the air work fine gets cold 97 have not done any work on it at all

72

Jeff, In march ’09 shop replaced my ’98 Audi A4 compressor, now 5 months later the system only blows warm air. Shop says they need to replace the low pressure line since “something” over time rubbed a hold in it allowing all the liquid to leak out. Shop says vibrations from driving over potholed roads could have caused this. I’m thinking they did not do something right when they replaced the compressor. Is it possible their explanation is correct? Should I be taking my car somewhere else for repair? Thanks!

73

Hi Corey, Sounds like the compressor might be running even if the fan is off. Check to see if the compressor is cycling when you have this condensation on the accumulator. Your fan may not be on but if the compressor is pushing freon through the system, then that would cause this to happen especially if the humidity levels are high. I hope this helps. Jeff

74

Hi Doug, This is possible, so the first thing I would do is to ask to see the hole in the line. You will be able tell if it happened that way or if it was created by the shop. If the do replace the line have them replace the drier as well if it hasn’t been changed out already, and new valve cores are always a good idea. Find out what kind of warranty they will offer and tell them to check the system for other potential problems so that if something else happens your covered. As far as your problem is concerned, I have seen friction wear a hole in the aluminum lines before so this is not unheard of. I hope this helps. Jeff

75

Hi Jeff:

I have a 2000 Chevy Surburban, the A/C was blowing hot air in the front and back so I took the car to my mechanic. He said he could not see any leaks after he charged the car and me $300 {He used the Neon Goggles}, after a week it was the same. Now I’m told the compressor may be shot but the problem may be under the dashboard. The cost is around $1500, is that possible?. Any help would be great, thanks!!

76

Hi Jeff, decided to make my 78 vette A/C functional again. changed condenser, comperssor, all hoses and lines, accumulator, evaporator, metering reed/valve, high pressure switch, blower and blower motor. Vaccumed and charged with 134A and proper ester oil with leak detector. No leaks. It blows cold at idle and around town. 58F at vent closest to evaporator. Gauge shows 40 PSI @1000 rpm and 95F ambiant temperature. All vent vaccum operated doors seem to work as does the heater core which was also replaced. On highway system ices up and flow air flow is restricted. Shouldn’t the compressor cycle at high rpm. Do you recommend a new thermostat cut out switch sensor or should I add additional freon at a higher rpm. Thoughts, Thanks.

77

Hi Justin, I quess my first question would be was the system low on freon. You said the mechanic had to charge the system. Freon does not leave the system unless there is a leak. Second was the A/C blowing cold after he worked on it. And third when you said that the air is blowing hot is it hotter then the outside air temp. I would need to know this first before I can give you advice on which way to go. Jeff

78

Hi Paul, your 78 vette originally came with R-12. I would have stayed with that freon instead of R-134a. Nothing cools like R-12. Did you replace the expansion valve? And no I would not add more freon. Once again the system was designed for R-12 and if you convert to 134a then you have to use less then what was called for from the factory. And yes the compressor should cycle at high rpm’s but if your system is icing up then you could have a restriction at the expansion valve. If you haven’t replaced it yet, I would but if you can afford it, stay with the R-12 freon. Jeff

79

Thanks for the quick response. Yes, expansion valve has been replaced. Iceing appears to start at the metal portion of the low pressure line at the compressor connection and spreads at high rpm toward the dryer, evaporator and up the small exit line (where the expansion valve is located inside the pipe) past the connection at the high pressure swtich. never quite made it all the way to the condenser. R-12 would have been nice, but i followed the advice of a corvette Expert? that recommended retrofitting for R134a. I believe lack of cycling is the issue as I can switch to vent only on the a/c control manually stopping the compressor and the ice melts almost instantly. Lot a condensate (water) is being shed from system prior to iceing. Not suprised as here in south louisiana humidity is usually very high.

80

A GM orfice tube has a grafite greyesh coating. It’s only a couple weeks from system recharge & vaccum only. Is this a sign of compressor
damage?

81

Hi John, It sounds like metal wear but I wouldn’t worry about it unless you either had black pieces of debris stuck to the screen or large pieces of metal there. Those are signs of compressor damage. I hope that helps . Jeff

82

Hi Paul, Icing is usually a good sign of blockage some where. I believe you replaced the cycling switch. In this case, you may have to take it in to have it looked at to solve this problem. Jeff

83

I have a 2000 Chrysler T&C and a/c does not cool. When I check the high and low pressure sides, the pressures are same even when the compressor is running. The a/c clutch is engaging and the low pressure side is at the correct pressure. Is this a problem with the compressor or is the expansion block stuck open?

Thanks in advance!

84

Thanks Jeff for the help and e-mail. You were correct, orfice tube was defective/blocked. Replaced and seems to be working fine. slight misunderstanding about expansion valve. Car does not have one. Great blog. You offer a very valuble service. Keep it up.

85

Hi Bob, I dont think its your H- block ( expansion block ) Bob. Sounds like the compressor is not compressing the freon. You may have a bent or even broken reed valve in the compressor. If you have a certified tech that you can trust, then I would take it to him for a complete diagnostic inspection. I know this is not what most people want to hear but if it is the compressor then you will need a new ( not reman ) one installed. I hope this helps. Jeff

86

Hey Jeff, I see you’ve answered alot of peoples questions on oil, and i read your responses carefully to try and keep from asking you a repeat question, but i couldn’t find the answer i was looking for. One of my car’s a/c line started leaking, it dripped tons of green oil all over my driveway. No way to estimate how much…but it was quite a bit. If it matters, it was the line from the condenser to the evaporator which includes the orifice tube. I replaced the line, the orifice tube, the accumulator, added 2oz to the line and 2 oz to the accum and vacuumed the system then recharged it. I just am wondering, how do i know if i have enough/too much oil in the system. I know how much “should” be in each component, you’ve explained that. Is there a test to see if you have the right mixture overall? Sorry for the long explanation, just thought i needed to explain myself, because everyone tells me, just put back however much came out…which i don’t know even if i did i don’t know if it had too much to begin with or what i was working with. Thank you so much in advance.

87

My ac was not blowing out cold air. Brought to a mechanic. They checked for leaks and did not find any. They then charged the ac/freon and charged $110.00. The ac worked for a day and stopped blowing out cold air again. Now they are putting in a new evaporator, which is a labor intensive job. Being that they charged me $110.00 for charging the freon and that did not correct the problem, should that money not be applied to current repair cost to replace the evaporator?

88

Hi Jayson, sounds like your doing everything right . This is a tricky question because you are not sure how much leaked out . I think you did right to compensate for the lost oil by adding two additional oz of oil. The oil that leaked out probably came from the condenser headed for the evaporator, so I would have added it to the inlet side of the condenser to replenish what was lost. The only thing that you can do now is to check your pressures and duct temp. If you know what your numbers should be then great but if not let me know and I will give them to you. So the big question would be is the system working properly. If so then I think you will be ok . If its doing something unusual then let me know and I will help you with it. Jeff

89

Hi Maryann Sounds like the shop you are taking it to is double charging you. If they had to add freon to your system to make it work, then you had a leak. If it leaked out in one day then its a good size leak. The shop should have been able to find a leak that big in your system unless the are using the old dye technique for finding leaks. But still they should have mentioned that its hard to spot a leak in the evaporator with dye and credit you your $110.00 towards the repair. I would ask for a $ 110.00 credit for the first freon charge that leaked out and if you do have them complete the repairs, ask to see your old evaporator after the work is finished and get a solid warranty. Make sure they don’t tack on an additional $ 110.00 on the back of the bill. If they have a problem with this go to a certified shop and report them to the BBB. I hope this helps. Jeff

90

Thanks a lot Jeff, that was comforting information. I have the low side and high side pressures and everything is in range, no strange noises, and a/c blows ice cold. Just didn’t know if low/high oil could cause long term problems. Thanks again

91

Thanks Jeff. With this information I will definitely address this with the repair shop. Very helpful info.

92

Hi Jeff,
Me again. So my evaporator was replaced and the ac is pumping out cold air… for now. However, driving my car yesterday about 35 miles, just barely home and I hear a nasty noise coming from under the hood. I get home an smoke is coming out from underneath the hood.
My brother knows something about cars and listened to the noise. He thought it might be the compressor. When the ac is off there is a noise happening that wasn’t there before but when the ac is on, the noise is like 10 times worse. Is this just a coincidence that now I have another problem going on right after my evaporator was replaced? Seems a little suspect to me. Needless to say I dropped it off to be checked again. Waiting to hear the prognosis.

93

So the I got the result of the noise going on under my hood. They tell me it’s the bearing in the compressor. The compressor does not have to be replaced but the labor for the repair will be 1 to -1 1/2 hours labor. Could this problem be a result of the ac being repaired or just a coincidence?

94

Jeff,
Have a question for you. My wife 2003 Chryslers Town and Country has had a problem with condesate leakage on to the floor board when you make a sharp turn. Up to today its has blown really cold it. We got back from a 100 mile drive, went to go pick my kids up from school and it just blows hot air. I can hear the compressor kick on and off. ANY THOUGHTS
THANKS MATT

95

Hi Maryann, first of all the smoke you mentioned in your last post has me concerned. If the smoke was freon then you would have warm air right after that. Second, as far as the bearing noise is concerned, when a compressor fails, it sounds like a lot of marbles in a tin can under your hood when the a/c is on. As far as a bearing going out in the compressor, that can happen but after everything you have told me I would ask for a new compressor. ( Not a re manufactured one). It sounds more like the clutch pack has failed which would have a burning smell to it. Magnetic clutches fail from having oil on them to low voltage running to them.I have the feeling Maryann that you might want a second opinion from a certified shop. I have seen this all to many times and I think it would be best for you to have it looked at by another shop ( ASE certified ) . I hope this helps. Jeff

96

Hi Matt, The condensation problem is usually contributed to a plugged drain tube that runs through the fire wall to drain the evaporator box. If the compressors cycles to fast, say on a few seconds then off a few seconds , then you have a low freon charge due to a leak. But if it cycles normally then I would check the blend doors by switching them from hot to cold to check for the doors opening and closing. Feel the suction line coming from the evaporator. It should feel cold. If not then you may have a blockage or inoperative H- block. Check to see if your fans are coming on. Last but not least check your pressures if you can. Low side 30-35 psi , High side 2.3 multiplied by the ambient temp. If you have a dual system then check the rear for cold air. If you do then freon levels are good. Back to the blend doors or H-block. I hope this helps. Jeff

97

Hi Jeff,

Actually the mechanic did end up changing the compressor because he said the compressor would only be $50.00 more than the bearing.
In the end another $295.00 dollars including labor.
Thanks for your response once again. Know any good mechanics in Queens New York?

98

Hi Maryann, I wish I did but Iam sorry no I dont know any mechanics in Queens. If you have any more questions, I would like to hear from you. Jeff

99

Hi Jeff,

I just spent the last 60 minutes reading this page. You are a wonderful person for providing such a valuable and time consuming service for us DIY folks. My questions are regarding low side pressure reads. 2003 Astro LS van w/front and rear A/C.
1. Would there be a difference in low side pressure(LSP)w/both components on versus just the front?
2. Should I be checking the LSP with both components on?
3. What would cause very high or very low pressure on the LSP?
4. Is there a common multiplier/divisor for determining the correct LSP?

Thank again for your time
JohnM

100

Hi John, Those are very good questions. For starters, question one, Yes. If you have only the front system on the pressures will be lower then if you have both systems running dure to the increase in heat load. Question 2. Yes but make sure the rear system fan is on low for a more accurate reading. Question 3. High pressure readings can be caused by but are not limited to condenser problems like plugging or restrictions either in or outside of the condenser,fan clutch or electric fan problems. Low pressures can be caused by restriction in the orifice tube or accumulator or even the restrictions in the evaporator. Question 4. Proper LSP should be around 30 to 40 unless you increase your heat load by increasing the rear A/C fan speed. I hope that has helped John. Jeff

101

thanks Jeff that helped

102

Hi Jeff. I must say I am impressed with the knowledge you have provided to all those visiting your site. You have an obvious desire to help others, which is very nice to see in the automotive repair industry.

I have a 96 Dodge Grand Voyager, 3.8L, original owner, and aside from transmission problems (they’re known for it) it has been an excellent vehicle. In January, I had to remove the dash to repair some burnt wiring, so I had the ac system discharged at a local shop. After a successful dash repair, I had the same shop recharge the ac system. It worked just fine. Well, the van sat in the garage until two weeks ago, while I addressed yet another transmission problem.

Now it’s all operating fine, except for the ac. Fuses are fine, compressor is cycling, but no cold air, no cold lines anywhere. The HVAC vents and flaps all seem to be operating normally in the dash. I am aware of the difference between low side and high side ports, but I can only find one port on this system. It is the larger diameter of the two lines from the compressor and is about 4-5 inches from the compressor. Suspecting that the refrigerant had slowly leaked out, I bought a recharge kit with a gauge. When I connected it to this only port I got a reading of 110PSI right off the bat.(engine off) Doesn’t sound like the low side port to me, but it is the only one I can see. Is there another port on this system that I have missed? (The setup appears to have the accumulator next to the condenser, and it has the Chrysler H block at the firewall) Any assistance/advice you can provide would be great. Thanks.

Dan

103

Hi Dan , The reading you got with the system off is normal. Remember that pressure and temp. with the system off will look similar. If you hooked up your gauges and turned the system on, then it should drop quickly to 30-35 psi. I always tell people that the suction line will be larger in diameter the the liquid line. There is a good reason for this. Pressure. The liquid line will have less chance of bursting under high pressures ( ie. 250 – 400psi ) if the line has a smaller inside diameter. Follow your suction line from the fire wall to the compressor. You will find the suction port or low side port this way. For the high side port, start at the compressor and work you way around to the condenser and then the drier . Sometimes the port will be hidden under the front grill or trim. I know this sounds crazy but they can be hidden here sometimes. If you bought a kit at a parts house, then chances are it will not fit on the high side port, which is good news for you. If you low side pressures with the compressor cycling are blow 20 psi, then your system is under charged. If you have a dual system then turn you rear a/c blower to low when checking pressures with the front system on high. I hope this answers your question Dan. Jeff

104

Jeff:

Hello. Today I bought a used 2002 Jetta with 116,000 miles. It runs great and the AC was cooling down to 58 degrees F. I charged it with most of one can using a basic AutoZone kit (R-134A) and the AC started blowing hot air. I suspect I overcharged it.

Now, how can I check to see if I did in fact overcharge it? Can this explain why the AC now blows hot air? How can I tell if I damaged the compressor or any parts? Can I release the pressure myself if it is overcharged?

I did this in Phoenix, ambient temp 100+, AC running (compressor engaged), freon added to low side port.

Thank you for your answer and time.

Ricardo

105

Hi Ricardo. It sounds like you might have overcharged the system. If you don’t have a set of A/C gauges then I would suggest investing in a kit that has the gauge on it. It will be color coded so you can tell if the pressures are right or not. Make sure the a/c is running and the blower is set to max. If a system is over charged it will blow warm air. As far as checking for a damaged compressor, listen to it after you get the pressures right. If it sounds like its rattling or chattering a lot then its damaged. And yes you can release the pressure out if it is over charged. Make sure the engine is off when you do this and there is plenty of ventilation so you wont become asphyxiated . After releasing some freon, put the gauge on the low side port and cycling the compressor by turning your a/c on. Take your time on this and and if you can, do invest in a digital thermometer to put in your air duct to check temp. I hope this helps. Jeff

106

Jeff:

Thank you for your reply.

Just to be clear–when I release pressure from my AC system (2002 Jetta) do I do it at the testing port that has a tag on it reading something like “Must test at 1 PSI”? It looks like the valves on a bicyle tire. Do I depress it (engine off!)with an open-ended hose abd connector, or simply depress with a piece of metal, pen, simiar firm object?

Also, do you offer ant DVDs on Ford F-150 AC systems? Home AC systems? Either way, I appreciate what you do and I am ‘buying you a cup of coffee’ just as soon as I fix this.

Than you, again.

Ricardo

107

Hi Ricardo, You can release it at the low side port. The tag the you have mentioned, if there is a green cap on it and it says must test at 1 psi then that is the EVAP test port. The port is usually on a black plastic line. This is not the port you want. Your low side port is on an aluminum line. If you release the freon by depressing the valve core make sure not to damage it or you will have a leak. Do not breathe in any of the freon. That is very important. And yes the engine must be off. I highly recommend that if you can afford it and know an A/C shop, then I would have them do it. They can get the freon recovered properly and the can get the system charged more accurately. As far as DVDs, we are currently making a DVD for the DIY on vehicle A/C that will explain everything in great detail. It should be finished by next month. Our current DVD explains how to perform brake jobs. I hope this helps

108

2003 Dodge Caravan Compressor replacement
I’m a novice do-it-yourself mechanic and have recently been told by an auto shop that I need a new a/c compressor & clutch along with a new a/c receiver drier. Total cost to repair $1100. I have researched and can purchase all needed OEM parts for $320. Here is my plan of action but wanted to run it by more experienced people to see if there are any flaws. I’d like to drive it (it is drivable) to a local shop about 5 miles away and have the system evacuated. Then I’d like to drive it home and replace the compressor and receiver drier. Can I drive the vehicle without any R134 in the system? Will it damage anything? Once I replace the parts I planned to recharge the system myself with cans of R134 I get from the auto parts store. Is there anything wrong with my logic and plans? Of course I’m just trying to save money but am looking for advice on whether my plan will work or should I just shell out the money? I’ve never worked on an a/c system before and would appreciate any advice. Thanks!

Mel

109

Hi Mel, I don’t blame you for trying to save some money by doing it yourself but there are a few things you should know before you tackle this job. First of all the compressor you buy should be new not a re manufactured one. The compressor should be drain of the factory oil and about 4oz of double end cap PAG should take its place. The drier will need about 1 oz of oil in it. You should have new seals for anything that has to be replaced. After the oil has been added to the compressor, rotate it by hand a couple of turns to keep it from locking up on start up. The service port valves should be replaced if you can while you have the system open. After everything is installed then you can take it down to your A/C shop to have it evacuated. About a half an hour on the pump. Ask the shop if they noticed a pressure drop after shutting off the pump and waiting 5 minutes. This will tell you if you have a leak. If everything is a go then charge your system on the low side with the correct amount of freon. Low side pressure should be around 30 to 35 psi and the high side should be ambient times 2.3 . This is only if you have a single system, if it is a dual system then I would take it in to a shop. That’s the quick version. That’s why shops will charge 1100 to 1500 dollars for that kind of job. I hope this helps . Jeff

110

Jeff – I have a 1991 F150 that I have owned since 1995. I’ve never done anything to the A/C except charge periodically. It sits on my farm and has not been charged for 2 years. I have considered Freeze-12 for a quick charge followed by leak detection (quick fix possibly or intermediate step if major leak) but if I do that I really should change connectors which will open the system – requiring evacuation and vacuum etc.

This is where I get slightly confused – about oil in the system. If you don’t flush and re-oil the compressor etc. how do you know what oil is in the system after evacuation and vacuum?

You recommend changing the accumulator and orifice tube after 5 years. I am trying to list the process I should follow, bearing in mind that I do all the rest of my mechanical work and have R134 gauge setup. It seems that if I decide on R134 conversion or whatever, I should evacuate the system, flush it, change accumulator and orifice (irrespective of R134 or whatever), vacuum the system, re-charge the system and then look for leaks.

Can you recommend steps, bearing in mind the age and suspected low freon and potential leak. Also how to re-oil the system – through low port or into the compressor etc., and also recommend flush system/procedure?

I have 2 cars with R12 and 3 with R134 and want to use this as a learning experience. I am not against buying a vacuum and getting a decent balance between pay/DIY.

Thanks (Nice site!!)
Gary

111

1997 Dodge Intrepid.

AC seems to be staying on all the time and freezing up the evaporator after 1/2 hour of driving.
Within 1/2 of driving, there is no air flow coming out of anywhere, regardless of the settings. You can hear the fan pushing air, but its not coming out of any of the interior ports.
When I park the car, after a while there is a large amount of water underneath at the r/f corner, just behind the tire.
But before the 1/2 hour driving is up, seems to work fine, air flow from all settings are good, heat works, cold works, etc. But when it is on cold, and you then turn on the ac, it is not noticeable, since the air is always ice cold.
I took the knee bolster off after driving it when the problem happened, so I could see everything, and found the section of the heater boz that houses the evaporator was ice cold!, even after 1 hour almost of not being turned on while I took the knee bolster, etc off to access it.

I had the AC recharged by an AC shop a couple of weeks ago, since it had never worked when I bought the car a while ago. They said the did a vacuum leak pull, things were fine, put a sealer into it, and topped up the refrigerant.

Ideas please?

112

1997 Intrepid part 2

Forgot to mention……

It blows ice cold air when started, even if parked out in the hot sun, or overnight.
Instant AC………..
I tried reconfiguring the heater control system as per a shop manual.
Turn fan on low, all the way to cold, and full defrost, then push and hold the rear defogger button until it flashed.
During the flash cycle it goes thru different modes, heat ,cool, defrost, floor, etc……then after 30 seconds it stops flashing as per the manual says. If the light stays on, there is further problems, but the light turns off, so the controller seems to be fine.

113

i have a 2003 nissan xterra. lately ive been noticing a foul odor coming fromt he A/C vents i replace the cabing air filter already and the smell is still there is there any suggestion that i can do to remove this smell.

114

Hi Darrell, The two things that I would check are the cycling switch and the H- Block.

115

Hi Gary, To start with if you have an R-12 system I would stick with R-12 and not try to retrofit. There are a number of reasons why I say this but number one is that nothing gets colder for vehicles then R-12. So if you can afford it, stick with R-12. As far as retrofits go I don’t recommend them or even give advice on how to do them. Sorry. Unless you have a large leak that has oil coming out with the freon or oil has left with the evacuation then chances are you still have same amount of oil in the system. There is no accurate why of knowing how much oil is in a system .If the system hasn’t been opened, then you can add oil through the Low side port with an oil injector, but if you replace a drier or accumulator then you add the oil to the component before you install it. Also I don’t recommend flushing a system unless its on straight lines due to the problem of flush being left over in a system will break down the new oil and destroy the compressor. The process for re-charging is correct, but keep in mind to charge through the low side port especially if you plan on using the compressor to help draw in the freon. This is critical because if you open the High side valve on your gauges while charging and the compressor cycles you could have the can or tank of freon explode from excessive pressure. Be careful. Leak detection is best done with a an electronic leak detector for about $ 130.00 dollars ( Robinair ) I hope this Helps. Jeff

116

Hi Ben, This is a very common problem, especially in places the have high humidity levels. Chances are that you might have a mold or fungi problem in your evaporator box. They sell kits for this but most of them require you to drill a small hole in the evaporator box in order to spray the fluid in. Very risky for your evaporator. You may have to take it to a certified shop to have them remove this smell from the box. One other thing I should mention. Pop the hood of your vehicle ans smell around the engine and battery. The smell could also be from something in the engine compartment that is being drawn into the cabin filter. I hope this helps. Jeff

117

I would like to get an answer to an oil usage requirement. Every where i read, everyone is saying put double end cap Pag oil in R134A systems. But I have ran accross this oil, PAO Oil 68 AA1 a synthetic oil that claims to work with all oils and freon.I just want to know the pro’s and con’s of using (PAO Oil 68 AA1 oil) over (double end cap Pag oil). Is it better to use a synthethic?

118

Hi Tony, That’s a very good question. I have heard a lot of good things about PAO oil and it sounds like it has all the qualities you would want out of a compressor oil. It can be used in any application as well, but I have not used it myself as of yet so I can’t give you any advice on its durability . I have used double end cap PAG for years and I know that it works very well so I stand behind it . I know this doesn’t answer your question about it but until I know for sure if it can stand up to its claims, I cant recommend it. I hope it helps. Jeff

119

Hi Jeff, My compressor is making a winding noise when I start my car, I think the bearings are gone, it still gets cold every now and then. I am about to replace my compressor,drier,condenser and expansion valve. I know from one of your post you don’t like flushing. But I have flushed out the a/c lines, because I can get all the solvent out of them. I did not replace the evaporator. Its still good, but I don’t know how clean it is, and I didn’t flush it because everyone say it is kinda hard to get all the solvent out of the evaporator. And that if you didn’t get all the solvent out it could break down the knew oil and cause your compressor to fail. What would you do with the evaporator, as far as making sure there is no junk in it? I also want to know would you put oil in each replacement item (compressor,drier…ect) as you put it back together, or wait until its all put back together and do it during the charging of the system?
I have a 2000 CLK 430,4.3L,V-8

120

Hi Tony, as far as the evaporator is concerned the only thing you can do to check if there is junk in it is to blow compressed air through the inlet and outlet tubes and see if any oil comes out. After that check to see if any small pieces of metal came out or a thick black oil which is signs of compressor failure. Other than that there’s not much you can do unless you pull it. Now when replacing components put oil in each one before you re assemble the system. Its very important Tony that you put the correct amount of oil and the right kind of oil in each part. If you don’t know then ask and I will tell you. I hope this helps. Jeff

121

Jeff, I have a 1999 chevy suburban 2wd 1500 5.7 vortec, the ac is not blowing cold air like it used to. It is not hot air coming out just not cold. The condenser is coming on when you turn the ac on, however when I turn the truck off you can hear a hissing noise from the passenger side, it lasts about 20/30 seconds then stops. Also on one of the service ports behind the condenser, when I took off the black cap and put my finger on it there was oil present? Can you please give me any insight into this problem. Thanks Kevin

122

Hi Kevin, It sounds like you might be low on freon due to a freon leak coming from the service port. The only way to know is to use a leak detector to find the leak and a good set of gauges to read the pressures. If you don’t have these then you may have to take it to a certified shop to have it checked, but if you have access to these tools, then I can tell you what to look for. Please don’t dump cans of freon into your system unless you can at least see the low side pressure. If you put to much in you can drive your head pressures up to the limit and nothing but warm air will come out. I hope this helps. Jeff

123

hi jeff, i have a 99 durango 5.2 and would like to know how the low temperture cut out switch bolted to the expansion valve works. it has 3 wires, one is battery volts from ignition, one is ac switch sense and the other is mode switch output. testes all other switches and relays and found this switch if umped from switch sense to mode switch output the ac works, also it will work if i grond pin 22 on the jtec controller c3 connector. testing results are my controller changes the voltage on pin 23 from battery volts to .5 volts but the pin 22 sense and pin 1 clutch relay stay battery voltage. the switch sense from pin 22 thru ac low pressure switch to mode switch output has battery voltage and i think it should be grounded or have .5 volts, can u help ? may need a pot of coffee :)

124

Hi Rick, are you having any issues with the pressure sensor on the H-block at this time. Is the clutch on the compressor cycling and is the temp at the ducts right. I’am just trying to understand what issues you may be having with the system. Jeff

125

Hi Jeff,
Recently bought a honda pilot 04 lx and my A/C stop blowing cold air (only air from outside temp). AC fan seems to be running, the compressor seems to be ok, I dont see any damage and oil leak on the condenser. Although underneath of the suv there seems to be some sort of green dye on one of the tube. My guess would be that the previous owner recharged it and put a dye to detect the leak as well. So now I was thinking of recharging it with Redtek R12a kit but Im not sure if I should and instead go to a shop to have them charge it w/ the R134 stuff. Could you please give some info on what I should do? Do I need to have a mechanic check/replace anything with in the AC system?
Thanks. :)

126

Jeff, I was able to borrow a leak detector and a set of gauges, here’s what I found. With gauges hooked up and engine idling the low side was 55 when compressor was not on and 70 when compressor on, high side was just above the 50 mark with compressor off and just a feww bars higher with compressor on. If I hold rpms at 1500 low side is 55 (off) and 80 (on) high side doesn’t change at all. The leak detector only went crazy when I removed the cap from the high side service port and put the sensor up to it. All other components checked out good, this is the same port that I said has oil around it. 1999 Chevy Suburban 5.7 vortec

127

Hi Manny, It sounds like you have a leak in the system. As far as the freon choice, I would stick with R-134a. The reason why is that RED TEK 12a is Flammable.
Below is the MSDS for this Refrigerant. If you go to a certified shop Manny have them fix the leak first and then charge the system or you will be back where you started. I hope this helps. Jeff
RED TEK® 12a Hydrocarbon Refrigerant
Replaces R 12, R 134a
301 12a 6 oz. Can (18 oz equivalent)
321 12a 5 oz. Can (15 oz equivalent)

Product Information Charging/installation guide
Material Safety Data Sheet Hydrocarbon Refrigerant Intro
Frequently Asked Questions Oil Selection Guide
Weight equivalent chart Elastomer compatibility guide
Vapor/pressure chart Packaging available

5 or 6 oz. Can
(15 or 18 oz. equivalent)

SECTION 1 – IDENTIFICATION

Manufacturer: Thermofluid Technologies, Inc.
Address: 409 Home Avenue
Maryville, TN 37804
Phone: (865) 983-1633
Fax: (865) 983-0068

Product Name: RED TEK?Dye 12a™ 6 oz can
Proper Shipping Name: Consumer Commodity; ORM-D
UN Number: N/A
Hazardous Goods: N/A
Uses: Refrigeration Systems

24 HOUR EMERGENCY TELEPHONE NUMBER
CHEMTREC: 1 – 800-424-9300 or 1-703-527-3887.

SECTION 2 – PHYSICAL PROPERTIES

APPEARANCE: Colourless gas; pine odour
ODOUR THRESHOLD: N/A
COEFF. WATER/OIL DIST: <1
FREEZING POINT: -267 F
VAPOR DENSITY: (est.) 1.76
VAPOR PRESSURE: (PSIG) 70@ 70 F
PHYSICAL STATE: Gas/Liquid
SPECIFIC GRAVITY: 0.540
EVAPORATION RATE: Rapid
BOILING POINT: -30.4 F
pH: N/A

SECTION 3 – FIRE OR EXPLOSIVE HAZARD

AUTO – IGNITION TEMPERATURE: 1585 F

FLASHPOINT: -34 C

LOWER FLAMMABLE LIMIT (LEL): 1.9%

UPPER FLAMMABLE LIMIT (UEL): 8.5%

EXTINGUISH MEDIA: If possible, stop flow of gas. Use water to cool fire – exposed tanks, surroundings and to protect personnel working on shutoff. Water spray, dry powder, or carbon dioxide can be directed at flame area to reduce fire intensity. Do not extinguish flames unless leak can be stopped.

HAZARDOUS COMBUSTION PRODUCTS: Normal combustion forms oxides of carbon.

SENSITIVITY TO STATIC DISCHARGE: Vapor may ignite if exposed to static discharge.

EXPLOSION DATA: Sensitivity to impact. Mixture is not sensitivity.
FIRE AND EXPLOSION HAZARD: Flammable vapor may form if allowed to mix with air. Accumulation of gas is an ignition hazard. Vapors are heavier than air and may travel to an ignition source

SECTION 4 – INGREDIENTS

Hazardous Ingredients % CAS Number L C50 P.E.L. ACGIH TLV
Alkanes 100 800 ppm 800 ppm

SECTION 5 – REACTIVITY DATA

CHEMICAL STABILITY: This material is chemically stable.

CONDITIONS TO AVOID: Propellant is flammable, avoid ignition source.

INCOMPATIBLE MATERIALS: Strong oxidizers.

DECOMPOSITION PRODUCTS: Burning of this product can produce oxides of carbon.

HAZARDOUS POLYMERIZATION: Will not occur.

POLYMERIZATION TO AVOID: None known.
SECTION 6 – HEALTH HAZARD

AS WITH MOST FLAMMABLE PRODUCTS: Do not expose to flames , sparks, torches, welding area.

INHALED/ASPHYXIANT: This product may cause irritation of the respiratory tract. May also cause headaches or dizziness at moderate exposures.Heavy exposure may cause anemia and irregular heart rhythm, respiratory arrest and death at elevated exposures.

EYE CONTACT: Irritating if the liquid gets into eyes, with a possible hazard from freezing due to rapid evaporation. Extremely high vapor concentration may also be irritating.

SKIN CONTACT: Exposure to rapidly expanding gas or vaporizing liquid may cause frost bite damage to tissue . Prolonged contact may irridate the skin and cause dermatitis.

CHRONIC: Prolonged exposure to this product may cause central nervous system disorder and/or damage.
SECTION 7 – FIRST AID

INHALED: In emergency situations, use proper respiratory protection and immediately remove the victim to fresh air. Administer artificial respiration if breathing has stopped. Seek medical attention promptly in serious cases of over exposure.

EYES: Flush eyes with tepid water for 15 minutes . Seek medical advice immediately.

SKIN: Avoid skin contact with the liquid . Remove contaminated clothing and wash the exposed area with soap and water.

FROSTBITE: Obtain medical assistance. If medical assistance is not available , place person in a warm area as soon as possible and allow the injured area to warm gradually. DO NOT WARM EXPOSED AREA TO EXCESS HEAT OR COLD.

INGESTION: Unlikely to be a problem , this should not occur.
SECTION 8 – SAFE HANDLING

SPILLS: Shut off ignition source and source of leak. Evacuate all non essential personnel from the area. If possible , ventilate the area. If mechanical ventilation is used, equipment must be explosion proof. Use water spray to disperse vapors. Isolate and ventilate area until gas has dispersed . If the incident is significant seek assistance from local fire, police, and other relevant authorities.

WASTE DISPOSAL METHOD: Dispose of product in accordance with local, county, provincial/state, and federal regulations.

STORAGE AND SHIPPING: Store in a cool , well ventilated area. Store away from strong oxidizing agents, chlorine dioxide, excessive heat and /or static discharge.

OTHER PRECAUTIONS: Empty containers may contain flammable or combustible vapors. Do not use without adequate precautions.
SECTION 9 – PERSONAL PROTECTION

ENGINEERING CONTROLS: Use only in a well ventilated area! Ensure there is good ventilation. If additional ventilation is needed use auxiliary ventilation equipment ensuring that all systems are well grounded and spark proof.

EYES: Wear chemical safety glasses with side shields and/or goggles.

GLOVES: Use thermal, chemical resistant gloves when handling this product.

OTHER PROTECTIVE CLOTHING: Long sleeves, pants and closed toe shoes.

RESPIRATORY PROTECTION: If ventilation of the area is not adequate use a jointly approved NIOSH/MESA respirator for organic vapours, to prevent overexposure by inhilation.
SECTION 10 – PREPERATION

128

Hi Kevin, besides being low on freon it sounds like you have a compressor issue. The low side pressure should have dropped down below 20 psi if its low on freon not climb higher. The high side should climb not stay even as with the engine off. As for the leak at the cap you will always have residual freon under the caps and with presence of oil you could have a small leak from the valve. Very common. You may end up having to take it to a certified shop for a more accurate diagnosis Kevin. Make sure if this is the case that it is a shop you can trust. I hope this helps. Jeff

129

Jeff,
Thank you so very much!! :)
You just made my decision a lot easier.
You are awesome!

130

hi Jeff, I was wondering if you could help me out…..I have A 2000 Chrysler grand voyager and the ac up front blows cool but not cold and when rear ac controls are turned on it only blows hot air in the back and only through the floor vents, nothing through the top vents. oh and also when ac is turned on my van makes a loud whistling noise only when you accelerate….but not when ac is off. My transmission just went out and its in the shop getting a new one put in but i wasnt sure if that had anything to do with the ac or not…please tell me what you think is wrong.

131

Hi Jeff:
I have a 1974 Corvette. The AC was last serviced prefessionally 13 years ago but this summer I have noticed that it doesn’t block cold air anymore. The compressor clutch does not engage when the AC controls are on. I am thinking of adding R12 myself. There may be a trace of oiliness on the back of the compressor at the center. Is is considered within tolerance for the R12 to eventually be lost over 13 years? There is a threaded port on a large diameter hose that runs between the compressor and the accumulator/evaporator. There is another port adjacent to a sight glass on a small metal line that runs from the condenser and the accumulator/evaporator. Also on this metal line is a compressor switch to turn off the unit if pressure is too low. I have the GM Service Manual but it is vague. Which is the low pressure port? Both ports appear to have 7/16″ threads and both have black caps. To start charging do I have to jump the compressor switch or will the freon by itself turn the switch on? Thank you.

132

Hi Brandy, for starters , no the transmission has nothing to do with your a/c problem. Second, Grand Voyagers are known for having rear a/c issues like the one you are experiencing. You will have to take it to a certified shop for testing and chances are they will tell you that you have a freon leak in the rear evaporator and possible a blend door problem. Have them check your serpentine belt as well . Hopefully the whistle sound is coming from that. If not then the pressure test that they should do will tell them if you have high head pressures causing extra load to be put on the belt. Don’t forget Brandy that if you do take it to a shop for an inspection that hey are ASE certified and that the shop is qualified to do A/C work. If you have questions about anything they tell you then run it by me and I will let you know if its right. I hope this helps. Jeff

133

Hi, about the Corvette, yes it is common to loose a freon charge over that many years of time. If you plan on charging your system with R-12 there are a few things to keep in mind. First R-12 was banned in Nov. of 1994 by the EPA which makes buying it difficult unless you have an IMACA license. Second, if you can get your hands on the R-12 then make sure you have some kind of gauge to know what your pressures are while adding the freon. The sight glass on the drier is a good way to know when the charge is right but you will need to know what to look for and for this info you will need a Haynes Techbook 10425 for A/C which is a good source for this. Third, the freon is charged through the suction line port which is the larger of the two lines you described. Never, and I cant stress this enough, never charge an A/C system on the High side. Most after market quick charge set up’s will have a connector that can only fit the low side ( Suction Line ) port but if you are using gauges you can make this mistake. To answer your last question, you can use the compressor to pull the rest of the charge in by using a jumper but try it first without one. Try spraying water over the condenser while charging. It drops the temperature of the the condenser which will make the freon enter it faster . Remember heat will always travel to a state of less heat, which means to say that freon will always flow to a state of less temperature then where it is stored. I hope this helps. Jeff

134

Dear Jeff:
Your help on the Corvette 1974 is very appreciated. I purchased the Haynes book. It turns out that my vehicle has a VIR near the firewall with a low pressure access port on top of it that is almost hidden under the fender. There is also a low pressure access port just off the compressor as well. The latter one is readily accessable. To use the port on the VIR I have to remove the supplemental coolant reservoir for the engine radiator. It seems a lot easier to go through the low pressure port near the compressor but I am concerned about potential problems to using this port in recharging refrigerant. I read that you don’t want to get any liquid freon to enter the compressor. Will this occur if the R12 can is kept upright with the compressor off or on? Should I just play it safe and go thru the VIR access port? Thanks for the help in advance. Basilio

135

Hi jeff, Im stuck doing a condenser replacement in my wife’s 2000 jetta and would greatly appreciate your advise.

A chip of glass from the road penetrated the condenser. Im keeping my fingers crossed the low pressure switch kicked in soon enough to prevent it from ruining the compressor. Picked up a new condenser and dryer.

Since the oil was lost in the process Im planning to bench the compressor drain it from whatever oil it has and put in a new fresh charge 4.5 oz of double capped pag46. From what I have read I should probably flush the system with compressed air and nitrogen (not flushing expansion valve or compressor. Im skeptical about opening up the expansion valve so that I can avoid flushing through it (in the spirit of if it is not broken dont fix it). Is it likely if I take care of the compressor and condenser there would be much oil left in the rest of the system or should I bite the bullet and do the flush?

For the freon I know using the 12oz cans is not the ideal method, but I dont have access to a 30lb tank and scale. I do however have a small electronic food scale that can weight a single can and tap before/after it’s use.

I found that if I attach the can tap and put it on the scale then I can determine the initial weight at the start and end. Using this method I think I can determine how much r134a that I used in total.

The problem/challenge is how to account for the freon used to purge the yellow hose at the start of each can, and I am also a little uncertain if I need to repurge the line when switching cans.

I have a set of robinair hoses that have a check valve type connect that supposedly shuts off inbetween. Im thinking that I can probably get by purging the yellow hose once and then rely on the check valve when swapping cans.

If the can swap idea with check valve works then I think I can account for the initial hose purge by purging the hose, shutting off the tap for the can, disconnecting it and weighing it so that I have the true starting weight.

Also on the target charge the vehicle by VW calls for 26+1.8 ounces and I am a little uncertain if the +1.8 ounces is intended to be the extra for hoses or machine or if this is part of the allowable target range.

My guage set has 6″ hoses and based on the initial 27oz target was planning on adding 2oz for the manifold/hoses i.e. target 28oz. It is now winter here in Ca so it is about 50 Degrees out. I was planning on warming the r134 to about 100 Deg to maximize extraction from the cans. Since the hoses will be at room temp, do I need to adjust/increase the 2oz allocated to the hose set?

Any pointers/suggestions appreciated.

Paul.

136

Hi Paul, Sorry for the delay on the reply, ( Holidays and Family in from out of town ) but to answer your questions I would not flush the system but you can use compressed air or nitrogen to blow out debris. I always tell people not to flush for a host of reasons. If OEM is with an orifice valve, then replace it at this point. Its cheap insurance. Make sure you add the oil to the new condenser before installing it and add the oil to the inlet tube, not the outlet tube on the condenser. I like the idea of using a small kitchen scale for the weight measurement. I found that if you use the green can taps , then you can switch between cans faster. Yes I would purge a little out of the yellow line each can swap. Once again it cheap insurance. I would assume at this point that you have a vacuum pump to evacuate he sytem first. Robinair makes a really good 6 cfm for about $300.00. They also make good leak detectors, which is would you should do after you run a pressure test. As far as the 1.8 ounces is concerned, I really would not worry about it that much. The book calls for 26 ounces only but if you want to account for freon in the line then simply add the difference after each can weight check. I don’t think you will have to worry about it though. As far as the last question is concerned, you can adjust for the temp difference but remember that you should only have 26 ounces of freon in the system when you are done. If the cans are warm and you purge the lines each time then the warmer freon will be in the lines so adjustment may not be needed. Sounds like you got it mostly covered Paul. If you have any more questions, feel free to ask. I hope this helps. Happy Holidays. Jeff

137

Jeff, thanks for the updates. Couple points I was not clear on.

Regarding the flush, compressor did not go out and all the oil that dripped out I could see looked clear. I was not planning solvent based flush, just compressed air. Is it ok to blow compressed air through the expansion valve or do I need to disconnect it and blow the air from the output?

The expansion valve seems to be pressure regulating type. A/C worked good prior to condenser puncture. Since compresser did not shrapnel I was not planning on replacing it ~50$ but might consider if you think it is suggested?

Regarding the oil addition I am a little confused where is best place to add it. Bentley had suggested adding all the oil to compressor itself and rotating it a few times to make sure it does not shock the compressor on startup. Other places show a breakup/rule of thumb budget of oil per component.

I removed the compressor so I could drain the oil from it. Am I ok to add most of the new oil all in compressor, half/half compressor/condenser suction side. I don’t want the vacuum cycle to suck it back out.

Regarding the yellow line purge, I am a little worried about how to account for the lost freon from the total charge for purging the lines. With cans it will take three times purging yellow hose. DIY said to purge with line cracked for about 10 seconds. Does this sound right and would this represent a significant loss of the charge?

Robinair hose set supposedly has a check valve type thing at the can connector port of the yellow hose. It seems like a sort of air tool quick disconnect but I have not tried it yet. Im thinking it may keep air from entering the hose when I disconnect/swap cans. If so I could pre-purge the hose, then start my measure/charge/measure routine with the three (2. cans. Might be safer to re-purge but Im worried about getting my total charge calculation to work out ok.

For the pump I have the little brother of the pump you mention the robinair 2 stage 1.5cfm. I was planning on letting it run a couple hours since it is not so strong. Hopefully this should be ok, but I could run it longer, im not in a hurry but dont want to damage the pump or system.

Thanks again, your assistance is greatly appreciated.

Any pointers/tips appreciated.

Paul.

138

i think my ac unit is stuck on and i cant get heat can i disconnect it?

139

Hi Clara, to answer your question in short, yes you can disconnect the A/C system without it affecting the engine performance but if your heater does not work there could be some other issues that need to be addressed first. If you tell me more about the make, model and year then I can help you diagnose your problem better. I hope this helps. Happy Holidays. Jeff

140

I have a 2004 Toyota corolla the a/c was working fine then it started to blow hot air after cutting the car off and waiting about 10 mins I started it back and had cold air I let the car run for 10 minutes or so and the air stayed cold then I drove the car and after about 10 miles it was blowing hot air. I was told this could happen if the feron was low but then some one else said no, what could be the cause and how hard is the fix

141

i took my car in to shop because air conditioner wasn’t blowing cold air. they discovered a leak in the low pressure hose area. my car is a nissan sentra 2001 gxe, how much should this repair cost?

142

Hi Lynn, well for starters I would check the cooling fans to make sure the are operating when the A/C is switched on. If you have a low freon charge, then the compressor will cycle on and off every 5 to 10 seconds. Also check the condenser at the front of the vehicle to make sure nothing is blocking air flow. ( ie. plastic bag, card board ) . After you have checked all these and you still have problems then check back with me and I will help you with it. Jeff

143

Hi Sadie , well that would depend on how much the shop charged per hour. ( ie 75.00 an hour up to 120.00 an hour ) . If they replace the hose or even the seals that job could cost you up to 450.00 but I don’t know how large the leak is. Some shops inject a sealer into the system if the leak is small enough and that costs less then a hose replacement. I hope this helps. Jeff

144

Hi Jeff, love your website!!! I have a 2001 dodge Durango. I have a problem. My A/c was just charged by my mechanic(my husband) and it has charged fine. Now the rear is blowing out ice cold air and the front is blowing out warm air. My husband says that the condensor and the compressor (i think thats what he said) are working fine. and he thinks that it might be a blocked valve. He is not the best at A/c work so he wants to talk to another mechanic when he gets off of vacation in another two weeks, and it is getting too hot here for me to wait that long. I have been checking everything I can, H valve, expansion valve, and I don’t know. He said he needs inout before he messes with anything else. Please help me!!! I would so greatly appreciate it! thanks so much!

145

Hi Heather, dual systems can be tricky to work with and you have to charge them right. I am guessing that your mechanic is using a set of gauges to help him determine the right pressures and to check for problems. As far as the H block is concerned, yes they can cause problems and Chrysler mounts them on the fire wall next to the evaporator. You can check there operation by feeling the inlet and outlet lines going to them. If the inlet is frosty, then you may have a restriction. If the outlet is frosty, then the valve is stuck open. Also something to think about is the blend doors ( A small door in the evaporator box the mixes cold air with warm air from the heater core ) I doubt it is stuck but it is possible. So Heather, check your pressures on the gauges and the inlet, outlet lines on the H-block on the fire wall. After that check back with me and let me know what you have. I hope this helps. Jeff

146

Hi Jeff, very informative site! . My teenager have a 97 saturn SL and there is a problem with the AC. The problem started a few weeks ago when the clutch was replaced by a local shop. Afterwards, the ac didnt blow cold. The strange thing is it blows cold air randomly then other times not cold. From reading from other post there isnt any strange unusal noises when the AC switch is turned on. Since getting it fixed the engine light comes on and off … and the AC only starts blowing out cold air when that light come on for some reason. Thanks
-Kiliani

147

Hi Kiliani Loui , sounds like the first thing to do is to let the shop that did the repairs know about your situation. Sometimes when a big job is done on a vehicle, other problems can happen if even just one wire or one vacuum tube is not back where it should be. Most of the time if you make the shop aware of it they will usually find the problem quick and have you back on the road in no time. That is why it is so important to choose your shop and mechanic wisely and that they are ASE certified. If after all that you are still having problems then I will give you a list of things to check. I hope this helps. Jeff

148

Hi Jeff, I have a 94 Chevy Lumina with a 3.1 V-6. I had to replace the compressor and of course, after the install it was necessary to
recharge the system. I’m a heavy believer in having either a Haynes or Chiltons manual for every car I own or have owned as I take a realistic approach to my shortcomings. Having said that, the manual addresses the compressor clutch not engaging if too low on R134a. The manual reads “you can pull the low pressure cycling switch plug from the evaporatorinlet line and attach a jumper wire across the terminals. This will keep the compressor ON”. Unfortunately, my trusty manual assumes I have knowledge in terms of completeing this task as it does not offer any insight as to how to accomplish this. I would be most grateful if you good guide me through this process as it does not seem complex in nature – I prefer to feel confident in what I’m doing before I do it as the alternatives could be costly.
Thank you so much for your consideration

149

Hi Michael, for starters you have to evacuate the system with a pump before you introduce freon to the system. A good 6 cfm Robinair pump is what we use. Vacuum down to as close to 30 in Hg as possible ( inches of mercury ) for about a half hour. When you installed your pump did it have oil in it and did you rotate it by hand a couple of times to prevent oil slugging. I know it seems like a lot but I would have checked and perhaps changed the orifice valve as well while I had the system open. This will tell you a lot just by looking at it and a new one is good insurance. Most cycling switches are located on the accumulator and you can run a jumper wire on it after you disconnect it from the switch. I am also assuming at this point ( very dangerous to assume ) that you have gauges and you know how to use them. After you get about a pound of freon in you can re-connect the cycling switch wire ( Pig tail ) and let the system do the rest. I hope this helps and by the way, only charge on the low side. Let me know if you have more questions. Jeff

150

I seem to be having some problems with my A/C in my car. Corolla 05. This has been a two year problem. I have taken it to an ac shop and they pulled a vacuum and added 2 oz r134a. Went back and said everything check out and it was normal for an ac to only be 60 for output temp. I went back saying the problem wasn’t fix they checked for leaks and couldn’t find any. They went ahead and told me The is normal for the air to only be coming out between 55-60 F and then go up to outside temp for a few seconds. I didn’t think so.

The ac system works fine if it is 80 or high but has a hard time cooling between 70-80. The compressor clicks on for 30 secs and then stays off for about a min. The temp reading go from 55 to whatever the outside temp is. I have been doing some test myself and if I bypass the relays and which keep the system on and fan on which makes the system work perfect 38 degree out. I have taken the pressures on 70df outside which is 140-120 high side and the low side is 25-45 the last number being when the compressor is off. I know my car has a temp senor on air out put temp. Do you think this could be bad? I have been in my friend’s corolla and his air is cold coming out which it is an 08.

151

Hi Danny, the first thing I would check is the amount of freon in your system. You will need gauges for this. Remember that freon pressure and ambient temp co inside with each other. The second thing to check is the cycling switch. Also high pressure cut off switches. Last your duct temp sensor. I know this sounds loke alot but if you check it yourself then you know for sure and will fell better about it. I hope this helps. Jeff

152

Hey Jeff, I have a 2006 Limited Expedition with about 89,000 miles. I was driving home from work today and I turned the AC on, soon after my wife called so I turned the intensity down so I could hear her. I quickly realized that it was stiil loud so I proceeded to turn it off.The front vents seemed to turn off, but the defroster/defogger was running full blast and wouldn’t turn off. It only turned off when I shut the car off. I have no idea what the problem could be. Thanks for your help!

153

Hi Jeff,

Nice site with good information. I have a 1992 Silhouette. The rear ac works great while the front ac is slightly warmer. I also noticed that only 1 of the two lines from the accumulator to the evaporators is cold. I think they should both be cold. The front and rear systems are separate and each has their own evaporator if that helps. Good pressure at 50 when compressor kicks on and everything else looks ok. Any insight would help.
Thank you,
John

154

Hi Jeff, I have a 2003 Lincoln Town Car Stretch Limo. I started it up today and the front a/c was blowing warm air. The weird thing is the rear a/c of the stretch portion of the limo was blowing ice cold. 2 weeks ago the entire vehicle was blowing warm so I took it in. They told me that the orfice tube was plugged and replaced it along with recharging the a/c. I’ve had entire vehicles blow warm befor but never just the front. Any ideas what may be causing this?

155

Hi Jason, sounds like a the front system has a plugged orifice valve. Check the return lines to check if they are cold or not. Jeff

156

Hi John, check the front orifice valve to see if it is plugged. Jeff

157

Hi Ryan, check the relays for that circuit first then the next thing would be the control head. Jeff

158

hi Jef thx for sharing ur knowledge… but here is my problem
i have my 1995 hyndia accent compresser changed to to a leackage in it …the AC worked just fine but 2 days later i had a tube blown up and oil was all over the engine.
In the shop the changed the damaged tube and just added new gas…after that my AC works fine for few minuts after turning it on then the air tempreture goes up. i won’t have hot air but it is not cold enough so when the tempreture is high the AC is doig me no good.
could you please advice about what could be the reason since the mechanique told me that he put gas in the AC as much as he can.
thx a lot for ur help.

159

bye the way today i passed by a new shop and they tried to add some more gass to the AC but nothing changed.
but i read on the Gass bottle R-12 will that cause me any problems since after reading the above conversations i know that different gasses shouldn,t be mixed.

160

and sorry for my bad writting ;)

161

Hi Jeff,
I’ve got a few questions about my 1989 Toyota Corolla DX sedan, but I’ll limit them to this a/c topic :-) My car’s a/c seems to work fine when the outside temp is 85 or below, but on the hot days, it will work for anywhere between 15 minutes straight to 45 minutes (with the compressor cycling on/off every 30 seconds or so as it always did) and then the air just gets warmer. I believe the compressor is still running at this point. What will wind up happening is that either I will shut the engine off, or the a/c switch for several minutes…maybe 15 or so, start it up again, and voila…the a/c is nice and cool again… for a while and then the process repeats itself. Any ideas?
Thanks, Ben

162

hi jeff thanks for ur information, i need to ask u smthg…
i have a hyundia accent 1995 my AC compresser was leacking gass so i change it the AC went great for 3 days befor an AC tube burs and oil was all over the motor.
i went to a shop he changed the tube added new gass without oil or changing a thing.
now my AC goes cold for a small time when i turn it on then the air becomes hotter so its better than outside but not cold.
i went to new shop they also added gass but i saw on the botle R-12 now i know that its not good with my 134 AC. but with all that the AC is still not working properly.
so could you please give me ur openoin about the problem and will the new added gass ( R-12) cause me any problems????

163

Hello Jeff,

I have a 2003 Mazda MPV w/ 130K miles.

The air conditioning is blowing cold air just fine, however, the cooling fan keeps cycling about every five seconds from “on” to “off” (or maybe between “low speed” and “high speed”).

The engine temperature is normal and the A/C coolant was just topped off.

My mechanic said it was the condensor’s fan that was cycling in this crazy fashion. He wasn’t sure why it was doing so. Any thoughts would be appreciated.

Regards,
Addison

Regards,
Addison

164

Hello. y name is Earl and I have a strange problem +with the A/c system in my 1995 Mazda Protege. When I take my car to an auto shop for A/C recharging the system charges like it supposed to initially. At random times after the service, A/C refrigerant burst from under the hood as if its under a tremendous amount of pressure. The mechanic at this shop tries to identify the point of leakage but can never find it. All we know is that its bursting in the front of engine. He couldn’t explain the cause. He let the car sit with the A/c on for about a hour and it never has that problem. It does it at random times. He did suggest that there may be a problem with the activation of cooling fan, thus causing a considerable amount of pressure. Please help me out with some possible solutions.

165

took off expansion valve on 1996 tcrysler town n country , found green pellets clogging it up . mechanic just guessing with my money now. could the dryer be bad ? he has no idea where these green pellets are coming from. I did use freon with sealer a while ago.

166

Help! Have a 2004 pt cruiser that was not blowing cold air. I was told compresser needed replaced which the mechanic did. it still was not working correctly but I needed the car for a short trip…when he drove the car to me and left it idle for us to switch cars all of a sudden a noise came from the car, like a pop and stream came out from under the hood. Is it safe to drive? What was this? I need to use the car and cannot leave it for him to look at..it was dark. Thoughts?

167

Hi Yolanda, I would have to say that if the ” Stream ” is engine coolant then no dont drive your car. If it is freon then yes you can drive it but you wont have A/C. Jeff

168

Upon opening hood I noticed lime green fluid…checke
d engi ne coolant which is rust colore not green and it is full

169

Hi Jeff,

I have an 89′ crx and changed the a/c to 134a. I replaced the expansion valve,receiver/drier,o-rings,pulled a vacuum,added 2 oz to compressor and put in about a can and a half of freon. The low side at 1500 rpms is 35-40 and high climbs to 300-350. My question is it normal for the two lines coming out of the receiver/drier to be real hot to the touch. Also, the compressor and condenser are extremely hot, but the air is 60 at idle and gets down to 40 while driving? Is the high side getting too high when it climbs while at 1500 rpms?

170

My AC stopped blowing cold. I’ve had the car for 8 yrs(2003 Toyota Matrix). I took it to shop and they charged the system. I should say they overcharged the system, it made a noise. It worked fine for 2 days but by the third day it started to make a loud noise periodically. I took it back, they said the pressure was too high and bled out some freon but it’s still making a sound so what do you think is happening?

171

I was reading all these responses and questions people have asked you. But i have a problem with my car it’s a 2005 ford fivehundred and my a/c was working fine one day and the next day it started blowing hot air when i am parked or at an idle and cold air when i am driving so i took it to a shop and they changed the expansion valve and the suction line but it is still doing the same thing what could be wrong with it any insight would be greatly appreciated.

172

Jeff
I own a 1996 Chevy Blazer. We just replaced the motor in it. The AC was working fine before,we did not unhook the system. Now the clutch will not engage. Just to be sure though we pulled a vacuum on it and recharged the system. Still the clutch would not engage. We changed the compressor AC relay,still noting. We even did a jumper wire on the cycle switch. No luck there either. We put a jumper wired on the relay contacts and the compressor kicked in. Called the Chevy place and they said it was a bad ground. But as far as we can tell all the ground wires are where they should be.We changed the compressor as well. Checked the voltage on the cycle switch it was 13.6 near the accumulator and the voltage on the regulator was 13.6. The voltage on the plug on the compressor side was less than 1 volt. We did while the car was off and the car was on. We are stumped please help!

173

Hi Jeff, Vehicle: Mazda Etude\Protage 1600 DOHC 1995, 220 000km Jeff only when I use the AC the car idles rough (250RPM~1000RPM) and only when the car warms up! Had the following Job at the mazda agent discription “Water pump cambelts V belts Removed engine mounting, removed compresser, replaced camblet, replaced water pump, replaced tensioner. Since then I had the car back to them 3 times and the proble presists! The following error was found “there is a possible fault to PCM it is not giving a signal for idle up to engine PCM no longer available at factory! Could the fault be due to AC! Would appreciate your advice!

174

hi Jeff, I have been having problems with my A/C as well as honest mechanics for the past 2 months… I’m hoping you can give me some answers. I have a 2003 Mazda 6 (85,000 miles) and 2 months ago 2 of my passanger fans started to blow a bit warm until the entire system started blowing warm. I took it to my mazda dealership where they told me i had a leak in my low-pressure AC hose. They went ahead and replaced it and 350 dollars later it started doing the same thing again (about 2 days later after they “replaced” the hose and charged it with freon). I went back and they kept the car over night to tell me that I need a new evaporator and that it would cost roughly 800 dollars. At this point I’m extremely angry and so I take it to a local mechanic. He replaces my evaporator and now not only does my car make strange vibrating noises and grinding noises when i press on the gas, but on the highway, the AC shuts off and its amlost as if it blows inside the car-not out. I then blast the AC and it slowly starts to come out but with droplets of water with the AC.By thw way, when he charged my car with freon, it was blowing SUPER cold. I take it back since I have a warranty, but he tells me its not his fault and that now my condenser needs to be replaced. The thing that confuses me is that when I do city driving the AC works just fine (the noises are still there), but as soon as I take on the the highway, the AC starts to blow IN not OUT, and this can be heard. Today the two AC vents that were began blowing warm from day one, are now again blowing warm. Its a matter of time until the entire AC begins to blow warm and here I am again going in a circle…1100 dollars later. Please help!!!

175

Hi Jeff , I have a Toyota Highlander Base 2007 model, You said that drier and accumualator last only about 5 yrs does this mean i need to change mine ? Is this process can be done by DIY , if not is this costly ? Greatly appreciate your advice.

176

Hi Reggie, Unless you are having issues with your A/C system then I would leave it alone for now. It is true that driers and accumulator are only good for 5 years I would not change them out unless you had to open the system for something else. As far as doing it yourself, if you know how to work a set of A/C gauges and a Vacuum pum,p I would say sure but if theses things sound strange to you then I would say no. I hope this helps. Jeff

177

Hey Jeff,

I have a 95 chevy 1500 pick up. I was on the road and the heater cut out. I went a couple of days without ac or heat. The ac clutch would not engage at all. Then all of a sudden the ac kicks in but only blows out very little air. It doesn’t matter if I have the control setting on high or low. The air that does come out is cold or hot depending if I have the ac or heater on. I figure I have a connection or a some kind of relay switch problem but I’m not sure. Any suggestions?

Thanks!!!

178

Hi Laz, The rule of thumb is to always check your fuses and relays first. After that I would pull the control head and check for for a possible short. Also the resistor block for the fan motor would cause the fan to blow at one speed but mostly on high. I hope that helps. Jeff

179

2002 Chevy Suburban 1500, front/rear A/C. Hello Jeff, Driving home after an oil change, I heard a terrible noise coming from under the hood. The noise occurred several times and the last time warm air started blowing from the A/C vents. My mechanic said I needed a new compressor. In the meantime he installed a belt. I’ve had the belt replaced 3 times, throwing good money after bad, but now I’m ready for a new compressor. I have two questions: If the A/C cooled perfectly with new belts, is the compressor bad? Questions #2, you’ve given excellent advice about the types of oil to use, rotate the compressor by hand, etc. Would I be out of line if I asked the mechanic to follow your suggestions and advice? I can afford to have this work done only once. Happy Valentine’s Day. Many thanks!

180

I have a 2004 Dodge Neon, and the air conditioner isnt blowing, it still feels like cold air coming through but its just not blowing. When I got out to check whats going on under the hood and the whole left side where the air conditioner stuff is located was completely frozen-covered in frost. It melted away pretty quick though. Please help me, I figured I would ask someone who knew whats going on before I go to a mechanic and get ripped off! Also my car has been cutting out lately. Thank you!!
Kayla

181

Hi Kayla, well for starters if there is no air coming out of the ducts when the fan is turned on I would say look at the fuses and relay for the fan first. If they are ok then check the switch on the control head and if thats ok then the blower motor itself may need to be replaced . Remember that the A/C system is a two part system. one for air flow over the evaporator and the other to transfer BTUs of heat thru the freon to the front of the vehicle where the condenser is.Thats where the compressor comes in. It sounds like your problem is with the blower motor, not the freon system . So even if the freon system isnt working you should still have air flow coming out of the air ducts. As far as the frosting is concerned, it could be a result of no air flow over the evaporator which in turn helps convert the low pressure liquid freon to a low pressure vapor . If you take it to a shop make sure they are ASE certified and if you feel you are getting the run around then get a second opinion. If you have more questions then I will try to answer them . Jeff

182

Jeff-
Thank you for taking the time to answer comments and for your wonderful site. I have a 09 Honda Accord with 53,000 miles. For some reason, the clutch won’t engage until I drive about 15-20mins. The air coming out is the same as the outside temp until the clutch is engaged. After engagement the air is cold and works perfectly. I have tried to take it to the shop but by the time I get there, the A/C is working fine again. They say all my fluid levels are ok and my pressures are ok. Do you think this is an electrical issue?

183

Hi Dan, That’s a good one. If you know of a good shop ask them to look at the cycling switch. You may have an issue with it. Also have them scan the climate control module for issues. Last have them check the voltage running to the clutch on the compressor. Anything below 11.5 v is not good . I hope this helps. Jeff

184

Jeff-
I have a 2007 Grand Caravan the back a/c works ok blowing cold are and having condensate dripping. The front a/c blows warm air cooler on the passenger side and warmer on the driver’s side. I know to have the recirculation button on to make it cooler no condensate drip in the front. What could cause this?

185

Hi Robert, It sounds like you either have an issue with the bled door for the front A/C or the the H block ( expansion valve ) is not working properly. Check the suction line coming from the front evaporator. If its real cold then check your blend doors. Jeff

186
Ashleigh Philbrick
April 26th, 2011 at 8:50 am

I have a 1995 Chysler New Yorker I took it to the shop to find out why 1st I had just had 2 cans of freion put in and the next day it was blowing hot again and 2nd the head unit could be off or on then all of a sudden the lights go off on the head unit and starts blowing hot air out of the defrost, I can hit the side of the unit and it will turn back on right and I can cut it off. They told me I had a leak in my evaporator core. I understand that could be whats causing the freion not to stay in but what about the blowing out the defrost thing and when I say hot air I mean hotter then the hot texas air I already deal with outside! PLEASE HELP ME!

187

Hi Ashleigh, to answer your question, yes it could be the control head that is causing hot air to come out the defrost vent but I would have the blend door actuator checked first. If the air is hotter than the ambient air then chances are that the blend door is open for the heater core. It could be stuck open or the actuator or servo could not be operating properly or the command from the control head is not being sent. As far as the leaking evaporator is concerned, I would get a second opinion due to the fact that the cost for replacement is going to be high. If in fact it is the evaporator , you can have the blend door inspected while they are in there . Remember to always get a second opinion and that they are certified to do the work. I hope this helps. Jeff

188

Jeff,

I have a 99 dodge caravan in perfect condition. Instead of making payments on another van, my paid off van runs fine except the air conditioner went out. Do you agree with my list;

1. New Air Compressor (Not Reman)
2. New condensor
3. New accumulator
4. New in line
5. New Double End Cap PAG oil with ICE 32

If I need any addtional parts would you comment and give me a “heads up” of what to look out for. I was told the system has to be very clean before the new system is installed?

Thanks

189

Hi Jane, it sounds like you have everything. I would check to see if it has rear a/c though because there are more components. Also chrysler uses an expansion H-block for freon control to the evaporator. If you are going this far I see no reason not to replace the H-block as well. Jeff

190

I am just trying to figure exactly what to order for my a/c on my 99 Dodge Grand Caravan repair.

1. How do find out which type of condensor my van has; with or without aux trans oil cooler?

2. My van has a blower for the rear a/c and heat, but the heat and a/c are controlled in the front console. So I was wondering if that means it has rear a/c even though it is just a blower and no other controls.

191

Hi Jane, One way is to use your VIN ( Vehicle Identification Number ) number on the door frame or up by the driver side windshield. Call the dealership with that and they will tell you what you have. If you have a rear blower then chances are you have dual A/C . Once again the dealership can tell you with that number. They usually ask for the last 8 or 9 numbers, but have the whole thing just in case they ask for it. Jeff

192
Abhinav Chadda
May 3rd, 2011 at 8:44 am

Hi Jeff,

nice article. I am having a strange problem with my car (2003 Dodge stratus coupe – 140K miles). The A/C blows out good cold air when it is on Highway. But when driving in city or at slow speeds, it does not cool at all. I would really appreciate it if you could give me some pointers before i take it to the mechanic as i am a student and can not really afford much.

Appreciate your help.

193

Well there are a couple of things you should check first. Turn the A/C on and listen for the fan to come on. If so look in the air intake in front of the condenser to see if there is a plastic bag blocking it. Next check the engine coolant levels to see if they are full. Next with the engine running and a/c on full check the small aluminum line ( Liquid line ) running into the firewall. Is it hot warm or cold. Next check the larger line ( Vapor line ) next to it coming out of the fire wall. Is it hot,warm or cold. Jeff

194

first of all i want to congratulate you guys for that mega website.it is very informative. u r doing a very good job. i have refilled my 94 camry ac system with 2 cans of R134a, each can containing 19 0z. I just read online that i should not have put more than 30 oz. i want to know if 6 0unces above the recommmended level can cause a major damage.

195

Hi Jean, Its never a good idea to put more freon in a system then it requires. Will it damage it ? You can by increasing the head pressure which in turn will bend or break valves in the compressor . To high of head pressure ( 500 psi and up ) can destroy a compressor. Did you evacuated the system first before adding freon? Was any of that 19 oz oil ? Are you using gauges ? The pressures will tell you a lot if you are ok or not. Jeff

196

Hi Jeff,
I just bought a 2000 SVT contour with a 2004 3.0 Taurus engine upgrade the ac blows warm air if its warm outside and cool air if its cool outside I see the compresser is turning and the cooling fan works aswell so I figured it needed to be charged. That did not work so I happened upon your site while trying to learn more about ac systems and I was hopping you could give me some pointers on what the problem could be.

Thank you
Dale

197

Hi Dale, I think the first question I have is how did you know how much freon to put in ( ie. pressure gauges ) . To little freon can be as bad as to much freon. With the system running, feel the liquid line and vapor lines at the firewall. How do they feel. Does the vapor line feel slightly cool or warm. Does the liquid line ( smallest in diameter ) fell warm or hot. If you are not sure I would recommend a good shop that has ASE certified mechanics to look at it. I hope this helps. Jeff

198

Hi Jeff,

I must compliment you on how much help you are providing to people. I think I saw a comment from you about Freeze-12 and you said it didn’t cool as well as R12. I redid the system in my 69 Pontiac Firebird and used Freeze-12 and everything seems to be working right but it’s not quite as cool as I would like. I also changed it to cycling clutch instead of the POV it originally had. Do you think it would cool better with R-12? I still have 4 cans of R-12 and could get one more and change it back to that. Besides that I have another question on whether or not it’s got enough freon in it. I put in exactly what the sticker on the system says it holds adjusted for the Freeze-12 instead of r-12. 3.75 x .8 = 3 pounds of Freeze-12 according the the Freeze-12 website.
The inlet is very cold just past the expansion valve. The outlet pipe is cold but probably not quite as cold as the inlet. Does that mean it’s got all the Freeze-12 it needs and there would be nothing gained by adding more? The other question I have is how low I can safely run the low side pressure without damaging anything. Its set now to cycle off at about 28 psi and it comes back on around 40 psi. It feels like I’m losing some cooling because it will cycle off and on enough that the off period lets the air temp rise enough to feel, I’m guessing a 5 degree rise. The system will easily pull down to 20 psi when the engine is up to 2000 rpm. I’ve tried it that way and that keeps it going longer which gives more “on” cycle time which gives lower outlet air temp. The humidity is very low here and freeze up is almost never a problem. Will it hurt the system to set the pressure switch to 20 instead of 28 if I’m willing to accept the increased chance of freeze up? I remember my Dad had a Mark V under-dash unit way back when and it would make ice cubes so I’m thinking they must have run the low side pretty low. Thanks for any insight into these questions.

Jim

199

Jeff,
99 dodge grand caravan. makes clunking noise when rocked back and forth. the noise comes from under the engine right in the middle. i feel it under the floor when i drive it. was just wondering if you had any ideas???
thanks
Jane

200

What would happen to the system if you were to put R-22 into a R-134a system and run it? My brother is having problems with his A/C, I am going to look at it for him this weekend, I don’t know if it has a leak but from what he told me it sounds like, it does. I was going to pressurize it with R-22 to use my sniffer and then go from there. I don’t have any R-12 if it does have a leak so I will probably put freeze 12 in it. I am EPA certified so getting R-12 won’t be a problem, that is if I can find any.
Thanks in advance.

201

I have a 86 Lincoln town car that has been retrofited for 134a, how can you tell if it has freon or the 134a in it?

202

Hi Jim, Freeze 12 is a legal drop in for r-12 but cannot trap heat like r-12. R-22 has butane in it so I would not use it in a vehicle. I would have stayed with the r-12 system originally. Your formula is right about the freeze 12 so I would not add more. More freon does not mean colder air. Because the system is not factory, I would say try to adjust the cycling time to increase freon movement. You are working with a lot of variables so I cannot say what is the exact formula to create the perfect duct temp. Jeff

203

Hi Jane check the motor mounts and torgue struts on the center cross member. The inner rubber mounts my be damaged or missing. Jeff

204

Hi Kelley, I would not put r-22 into a r-134a system for a lot of reasons. The primary reason is that r-22 has butane in it. If it came with a r-134a system in it then I would stay with that freon. I don’t advocate retrofitting a system due to the fact that they dont perform very well after that. Jeff

205

Hi T-Roy, the easiest way to tell if the system has a charge in it is to turn on the a/c and see if the compressor kicks on. The most accurate way is with a set of freon gauges. As far as telling whats in the system, that would require a freon identifier. Jeff

206

Hey Jeff,
I have a 97 vw jetta and the a/c is blowing warm. compressor is running when a/c is turned on and not running when a/c is off. i put a guage on the system and its showing that it is overcharged, would this be the reason why its blowing warm?. If you could lead me in the right direction to fixing my a/c it would be greatly appreciated!

207

Hi Jeff.

My compressor wasn’t working so I filled with 16oz of R-134a and then at less than 1/4 remaining in can the compressor started with very cold air. Now when AC is pressed only fan air comes out BUT I can see the compressor spinning and condensation coming from the line going into evaporator core. From reading other responses the most likely cause is my “blend doors” Where are they located.

1. Where are blend doors located? (2001 Pontiac Sunfire)
2. Fan blower speeds 1 & 2 don’t work. 3 & 4 work just fine.

Feedback will be much appreciated !

208

Hi Jamie, Yes that is a good reason why it is blowing warm. The first question I would have is who put the additional freon in the system . The only way to fix the problem is to evacuate the system and recharge it with the accurate amount of freon. It should be posted somewhere in the engine compartment. Some people try to top off or drop the freon down until the pressures are with in range but that is guess work and some systems are very charge specific. Jeff

209

Hi Ron, most if not all blend doors are located in the exchange box under the dash. If you look up under the passenger side of the dash you will see a large black plastic box. That is it. The actuator is sometimes located on top or on the side of the box. Fan blower speed is regulated by a resistor block but if you can check the control head first to see if both of your problems are from one source. Jeff

210

I have been trying to determine the proper amount of refrigerant and oil to use in my 1989 S-10 with a 2.5L engine.
GM label under the hood:
R-12 charge – 2.5 lbs
Oil amount not stated
GM Service Manual for 1989 S-10 Light Duty Truck:
pp 1B-5
Refrigerant and Oil Capacity
R-12 – 2.5 lbs
525 Viscosity Oil – 10 oz
pp 1B-49
Specifications for DA-V5 Compressor
System Capacities
Refrigerant – 3 lbs 8 oz
525 Viscosity Oil – 8 oz
NapaCapacityGuide2-8-05.pdf
pp 9
S-10 Pickup, 89, All Eng
R-12 – 56 oz
Mineral – 8 oz
What would you recommend?
Thank you.

211

Hi Jerry, I would put 8 oz of mineral oil in the system and 2.5 lbs of r-12 of freon in . The early r-12 systems are not as critical as the later r-134a system are. Jeff

212

I have a 1985 Chevrolet S10 pickup, 2.8 point liter engine, and I can’t get the A/C to blow from the vents mounted in the dash. Air comes out on the floor and it will not defrost. The pickup came from California. We’ve owned it for 10 years. Can you help me trouble shoot this problem? Thanks, Glynn Glover

213

Jeff,

I own a 2002 Ford Econline, 5.4L. The AC Clutch does not engage. I’ve looked for fuses or relays that control it. No luck. The Owners Manual only identifies fuses for 4.2L engine only. There is no freon pressure in system, All fans work. The compressor does not engage in Defrost as well. Is there a way to replace clutch without replacing Compressor? Is it worth it in the long run?

Thanks

Michele

214

Jeff, I’m going to change the rear evaporator in my ’06 Dodge Grand Caravan w/ a 3.8L V6. How much oil do I need to add? If I use freon with oil do I need to add oil separately? Thanks.

215

Trying to put 134-A freon into a line, but the low-side service port was corroded and valve core stuck. Got the valve core unstuck and the recharge coupler on the line but the freon is leaking out when we try to recharge because the service port coupler is pitted from the corrosion. O-ring in the recharge coupler looks good. Is there an easy way to replace the service port (looks built-in to the line)? Or should we replace the valve core and try again? Would the service port being pitted cause this problem?
Thanks

216

Hi Jeff,
Thanks for sharing your impressive knowledge with us. I have the following problem; Any insight would be greatly appreciated.

I, trying to be a A/C mechanic, decided to add Freon to my Vehicle. I think I added too much as my compressor began turning on and off repeatedly over and over again and the air coming out was warm. I then leaked some of the freon out and the compressor began to run for longer periods of time and the air became colder again.

Here is my problem- Today, running my car in 90+ degree temperature, I noticed that the A/C would run cold when I was moving down the road/highway. However, when I stopped at a red light or in traffic it would become warm (almost humid).

I bought the do-it-yourself kit at the local auto parts store with a primitive gauge and I thought I filled it correctly. Anyway, what do you suggest? I drive a 2004 Mazda 6.

Thanks,
Alex

217

Hi Glynn, The first thing to check is the vacuum actuators that route the air. They can be found on the sides of the exchange box. The early design used vacuum controlled dash pots or actuators which later went on to become servo units. You may have a vacuum leak in the lines that control them . Jeff

218

Hi Michele, If there is no freon in the system then the clutch will not cycle. If you want to check for clutch operation then remove the pig tail from the cycling switch and use a jumper wire to connect the circuit . The clutch should engage but if there is no freon in the system I would recommend doing this for just a second or two due to the fact that freon and oil travel together. No freon, no oil movement and compressor damage. As far as replacing the clutch, yes it can be done but I would not recommend it for a host of reasons. Jeff

219

Hi Steve, the job you are about to undertake can be tricky if not performed properly. The rule of thumb for evaporators is about Two oz of oil. I would add the oil separate from the freon for a more accurate charge. If you are in doubt of any of the procedure then I would recommend a certified A/C tech. Jeff

220

Hi Troy, I would replace the valve cores first then try again. If the pitting that you are seeing is bad enough, then that can create a breech for the freon. Some service ports are replaceable while others are permanently built into the line. Jeff

221

Hi Alex, “Semper Fi” This is a very common problem with the ” do it your selfers ” . Too much freon is as bad if not worse then not enough. Too much freon can cause excessive head pressure thus tripping the high pressure transducer and in turn shutting off the compressor. More freon makes the system run warm. The first question would be if you added freon, the reason would probably be due to a poorly operating system. If freon levels are low then the leak must be found. If there is a restriction somewhere then it must be found. As far as what to do, I would evacuate the system for 1/2 hour and recharge it to the proper amount based off the label inside the engine compartment. If you continue to have problems then you know the charge is correct and you can move to the next problem. If you really want to do your own A/C then invest in a set of Quality gauges. A vacuum pump ( Robinair preferably ) from http://www.thetoolwarehouse.net/ can be bought starting at $ 100.00 dollars. This way you know for sure what is in the system and you wont pay a lot for repairs. Jeff

222

Hi!

New Relay installed, A/C blows cold for 5-minutes, then warm. When I turn it off for about 10-15 minutes, it blows cold again. It’s almost as something is overheating, and when it cools down the A/C work again.

What can it be?

Jose

223

Jeff,

Semper Fi. I figured I added too much freon. I added more because I thought it wasn’t cold enough. Guess I should have been satisfied. Oh well, I’ll invest in some good gauges and rectify my problem. Thanks for your help.

Oh one more thing? Is it dangerous to run before I fix it? What could be the consequences?

Thanks.

224

Hi Alex , that all depends on the head pressures. That is why gauges are so important. If the head pressure begins to spike you may get a leak in the system if you have a weak spot or if the pressures are to high a bent valve will result. Then again you may be in the safety zone, its hard to know with out seeing the pressures. Jeff

225

Hi Jeff, I have a 2004 Nissan Xterra and when the car is at idle the compressor makes a clicking noise and blows warm air. When I start moving the air becomes cooler and I do not seem to hear the clicking. Does it sound like my compressor is going out? I just had the ac recharged but, it did not seem to make a difference. Thanks for any help you can offer.

226

Hi Jose, are the cooling fans turning on ? Jeff

227

Hi Marty, if the compressor is making a clicking noise, then you may have an overcharge system or the teflon rings are destroyed causing piston slap in the compressor. Have the pressures checked first. Jeff

228

Hi Jeff, I have a Toyota Camry 1995 XLE V6 and every time i would turn on the A/C, my car would start making this screeching noise. But just recently, I was driving and suddenly my A/C just cut off and it caused the RPM and the windows to stop working. Various of people have told me that it’s the air compressor, but others tell me its the A/C blower/fan. What do you think it could be?

Yelany

229

Hi Yelany It sounds like your compressor is loading up. With the engine cold, see if you can spin the compressor with your hand ( engine is off of course ). If not then you have a locked up compressor. If you can then check the belts the drive the compressor for proper tension. Jeff

230

Took my car to the dealer where I bought it. Air Conditioner was not blowing cold air. My car is a 2009 Dodge Caravan. It is still under warranty. They said the freon was low. They filled it and now two days later it is blowing warm air again. They said it did not have any leaks because they did a dye test on it. Something is wrong. I had to pay then $250. What do I do?

231

Hi Martha, I don;t think you should have had to pay $250 for a warranty item unless there is a deductible for the repairs. As far as the A/C is concerned if it is blowing warm again then first take it to a shop you know and trust and have them check the freon levels. If the system is low and the leak due to dye injection can be seen then ask for a print out. It may cost you a couple of bucks but will be worth it. If it is low on freon ( i.e. a leak) then take it back to the dealership and if they try the old no leak line again then you can show them the document and then ask for the service manager. Tell him or her that if this problem isn’t corrected then you will notify the BBB, the local news agency and the District Attorney’s office for fraud. This should get there attention. Jeff

232

hi Jeff, I have a similar situation as Niki wrote about in June, 2009 but I could’t find your response. I have a 2000 Ford Taurus sedan, the ac was blowing warm air and a couple weeks ago we brought it to the shop. They checked for leaks, found none and recharged it with ~1 lb freon. They also told us the valve cover gaskets, upper plenty gasket needed to be replaced and the throttle body needed to be cleaned. At that time we did not get this other work done. The ac worked like a champ around town. Then yesterday we got the other work done. we’re not sure if that is related but we took the car for a drive and all worked fine at first. But when we got onto the highway the ac shut off when we reached ~60 mph. We drove on the highway for awhile, then got off. The ac kicked back on a lower speed. Then we got back onto the highway,when we reached ~60 it kicked back off. We drove for awhile and got back off. At lower speed it kicked back on. Any ideas on what would cause this?

233

hi jeff
every time i try and put freon in my car a 2001 dodge intrepid es the frion starts smoking out of the hood and comes thru the vents inside my car just wondering if this means i need to replace my compressor.also whenever this happens my husband leaks the frion out and it starts working again but the gages say its low??

234

Jeff, I have a 2004 Nissan Quest minivan. I’ve had problems with a leak in the A/C system for the past year. The dealer replaced the low pressure side hose. A week later the freon leaked out. Took it back, they said schrader valve needed tightening. The Freon leaked out again. I took it to an independent shop this week and (using UV dye to check) they said the evaporator core is leaking inside, underneath the dash. They will have to take apart the dash etc… They stated it was a 8 hour job.

Is it common/rare for the evaporator core to leak? Before, they are making the repairs, are there any other questions I should ask them? While they have the dash apart and the system open, is there anything else I should make sure they do or replace? Expansion Valve? O-rings? Condenser? Receiver/Dryer? Accumulator? etc…

Great amount of knowledge you have Jeff, Thanks for helping so many people!

235

Hi! I have cressida 1991 and problem in my AC i would ask on how to fix the warm air coming from my AC blower and please advice the method of AC flushing?

236

Problem…(A/C not blowing cold at all WARM AIR before (short belt) and after work/replacements performed) bought 99 Maxima 3.0L Automatic. Compressor had the belt removed and shorter belt was running alternator only. After further inspection the clutch bearing had locked up the pulley. Removed the compressor (repl w/reman) and replaced the expansion valve and drier also. Evaporator was very dirty and flow was not good through fins. Cleaned carefully and now air should flow over the evaporator at normal rates. Pulled a good vacuum on the system and put 3 cans of 134 in. I did notice an immediate cooling with the 1st can. After 3rd can and then taking a gauge reading I noticed that the high side does not register above 140psi and the low side will not drop below 80-90. No matter what I do. Please help, where should I be looking. Some are saying condensor…(I do not see any signs of a restriction with these pressure characteristics…..) Please help, current readings having low side too high and high side too low indicate compressor not working. Tomorrow I will replace the reman with a new compressor and recharge…am I doing the right thing….I’m in the 500-600 dollar range on this repair and about to thro up my hands. Tks for answers to: gandl2123@comcast.net

237

If you answer directs me to my problem I will surely donate as your service is commendable. Tks

238

Hi Gregg, First thing I would ask is was there any internal damage to the compressor. If so the first place damaged compressor pieces go to is the condenser. If so it should be replaced not flushed. Second, never ever ever use a rem compressor if you plan on keeping the vehicle. Third, use a double end cap PAG oil 9 approx 4 oz in the compressor. Remember to turn the compressor by hand a couple of times first before firing it up to prevent slugging it with oil. Jeff

239

Hi Mike, I need to know more about what is going on with the system before I can answer that. I would only flush on large tubes or straight lines, never evaps or condensers. Jeff

240

Hi Stuart, no it is not rare for the evaporator to leak but I would be asking the Dealership why they could not find this problem to start with if this is all that it is. They should replace the receiver dryer since they only last for 4 to 5 years. If it was only a leak then you should be ok with the other items. The shop that is doing the repairs should replace the seals associated with the repair and then leak test. The valve cores should be replaced while the system is open. Jeff

241

Hi Nicole, before you start replacing components, you first need to know where the leak is . If the freon is coming through the vents and the vents for recirculation is closed then that could mean an evaporator leak. The system will work on low freon and the leak is probably only evident ( White cloud ) with higher pressures. The leak is still there but with a low charge you will not have the visible freon cloud. Find the source first then replace the defective component. Jeff

242

Hi Tim , If the system had to be recharged with a pound of freon then yes you do have a leak somewhere. That should be the first question you ask a shop if they have to recharge the system with that much freon. As far as the other repairs are concerned, throttle body cleaning is not always needed and upper plenum gasket leaks will cause a check engine light to come on ( banks 1 and 2 running lean ). If the shop that did the repairs is a trusted one then tell them your issue and they should check into it with no question. Jeff

243

Hi Jeff, 1993 Honda accord se coupe, a/c finally went out after 18 years and 215,000 miles…noticed it was not cooling as well over past 3 years. Jumped the low pres switch and conden fan and compressor came on, also sight glass was bubbling and streaking. Decided to throw a can of r-12 in it…got a can tapper and hose and when I went to put it in low side (right in front by radiator cap) the Schroeder valve was inner diameter threaded? Can’t find an adapter anywhere…this vehicle has been in family since new, and no one has ever taken the a/c system for any service. What can you tell me about this and where might I get an adapter? thanks, Scott

244

Hi Jeff, I have a problem with my 97 honda accord. I just replaced my evaporator (leak) and expantion valve and dryer. Vacuumed system and held overnight,charged with 2 cans of r134 12oz. (req 24oz.) max. Also 1 can of oil 2oz. Temp. coming out of vent is 58, thats driving on highway at 65mph. Tested temp on 09 Accord it reads 40 at 65mph. Both on 100 degree day. So I added another half can. Do you think thats all im going to get out of it. Or should I evacuate again and recharge. I still need to take a reading on gauges in the morning. Thanks for help.

245

Hi Scott, You might have to check with the manufacturer on that one. The service port you described is very rare . There are a few after market companies out there that might have the adapter you need . http://www.ntxtools.com/ http://www.thetoolwarehouse.net/ . Jeff

246

Hi Mike, I think I would evacuate and recharge with the exact amount. When you replaced the evaporator, you should have added the oil to it with the system open and directly into the evaporator. ( 2 oz ) After you recharge it again run it for a little while to get the oil to circulate . Jeff

247

2000 Ford focus. Some time after an engine rebuild I routed one of the hoses under the condenser and after awhile it cut through. I bought a new hose from the dealer to the accumulator and also a new accumulator. Upon having it filled some how I burned up the compressor. I Replaced the compressor and charged system and it was fine and getting cold everything seemed to be read fine on the service port(on the accumulator) 25 to 35 psi. Until the car sat for 2 hours now the clutch cycles on and off. The service port now reads 45 psi and as quickly goes up to 65 at which point the compressor shuts off and the cycle continues over and over. Where to go from here ?

Thanks Jon

248

Hi Jon, just a few questions first. Did you have the system properly evacuated before having it charge. ( ie moisture ) Is the compressor new or re-man. Did you have the orifice valve replaced. Was the high side pressures reading ok before your problem. Any one of these things can cause a problem. Jeff

249

I took it to a shop after installing the compressor and they suggested to replace the pressure switch. They evacuated the system. I installed a new pressure switch and the compressor is a re-man. I’ll check the high pressure side later on today. The shop never mentioned a problem with the high pressure readings. I only have the kit for refill from the low pressure side. But the compressor is doing the same thing it did when they evac charged it as when I did with my set. On for 5 secs then off. After reading your info on the page I am assuming that ambient temp would be outside temp X 2.3. I also noticed that since I burned my compressor once I may need to replace my condenser. The orifice valve has not been replaced but will be soon. You have alot of great info on this page and I clicked every ad I could see. Thank you for sharing your knowledge and giving everyone a better understanding of AC systems.
Thanks again Jon

250

Well I put about a can of Freon in my wife’s Chevy lumina 1999 and still the clutch will not kick in any hints Jeff?

Using cauges both reda 100 psi

251

Hi Jeff , you may have an electrical issue. Try using a jumper wire on the cycling switch ( located on the side of the accumulator ) If the compressor still doesn’t cycle then check your connections at the compressor. After that I would check the relay and control head. Jeff

252

Hi Jeff I have a bmw 540i 2002 model. It is only blowing hot air from the a/c and there is an extremly loud fan noise as if the fanis running on overdrive. It sounds like a jet engine. My husband took it to one place they put in a 50.00 computer and still nothing and no one else has got a clue. If the compressor is “straight” wired it will cut on and does run the a/c cold also its full of freon no leaks and has been charged…any info you might have would be great.

253

Hi Kelly, I would recommend taking it to a shop that deals with European based vehicles only. The BMW series is a complex vehicle and can be tricky to work on and unless you know what you are doing, you will never figure it out. Jeff

254

Hey Jeff,
I have a 2003 Hyundai Tiburon that runs cool for a day or two after I charge the system. the compressor kicks on fine once the system is charged, and like i said, runs cool and then progressively gets warmer until it runs out. Do you know of any common leak areas on this car? Any input would be appreciated, thanks!

255

I have inadvetaly reved my engine to the red-line a couple of times. Can you damage a compressor (honda) by over reving?

256

Hi Mike, you should by ok. Jeff

257

I have a 1994 maxima. Ac blows hot air only. Charged with freon. Still no cold air. I opened hood and noticed fans not turning. Do they eventually kick on

258

Hi Jeff , I have a 06 e-350 with a 6.0 diesel i,ve replace the a/c compressor 3 times because of lack of cooling its got a add-on rear unit the high pressure gauge is jumping almost like vibratingand even low pressure is jumping some its around 60 psi on low side the front evap lines will be cold then theyll get hot front vent around 65 degrees rear around 48 degrees.these are new motorcraft compressors.i have been taught when your high side gauge shakes steady its a bad compressor shouldnt be 3 in a row. i,m thinking blockage in the evaporatercause add on has its own evaporater and expansion valve .thanks tim

259

1992 camry was converted to r134 about 5 yr ago. now the air is cold at 40+mph but min.cool at idle or low speed of traffic.
my rpm gague and radio stopped working about the same time. Could they
all be related to an electrical problem?
my ac low pressure reading is in the 30′S.

please give me any help you can
thank you
6/25/11

260

Hi Jeff, I have a 1999,f/350 diesel I have replaced the condenser,compressor,orifice,and the drier everything looks good. I vacuumed it down for 45 min gauge never moved so that told me everything is sealed? I went to charge it with Freon and nothing? It will not take anything! I want to literally blow it up! Do you have any suggestions on what I am not doing/missing? an I also flushed/aired the high lines using a little acetone came out clear on the other end. My husband and I have already spent about 650.00 dollars what in the world could it possibly be when everything is new…. My husband will not ask you he’s trying to figure it out on his own!!! This scares me!!! I do not want to buy all the parts again!!! Please help!!!

Thanks
(secretly from my husband)
LeeAnn

261
Sheldon Altschul
June 26th, 2011 at 12:26 am

Hi Jeff,

I have a 1996 Subaru Outback. The A/C blows very cold for a while until, I think, the high pressure switch opens and shuts off the compressor. After a while, it will start cooling again.

I hooked up an thermometer to the center console vent and observed that even if it’s in the high 90s it will cool the air down to the high 40′s before it cuts out. If I watch the temperature and manually turn off the A/C when the temperature gets to the mid 50s I can keep the A/C cooling all day. It will not cut out. Of course, if I miss it, I have to run without A/C until the high pressure switch closes again.

The mechanic says I need an expansion valve. I don’t understand how that would cause the problem. To my way of thinking, it sounds like an A/C thermostat problem.

Can you give me some insight into my problem?

Thanks,

Shel

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Thanks Jeff will do sorry about the late get back busy as heck here.

Jeff

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Hi Ben, Yes they should kick on with in a minute or two. Jeff

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Hi LeeAnn, First of all when you say it ill not take any freon, do you mean that the compressor is not cycling. Try jumping the cycling switch to use the compressor to pull the freon in with the engine running. Water on the condenser while doing this will decrease transfer time. Make sure you always charge on the suction side ( Low side ) . Jeff

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Hi Sheldon, If the High Pressure transducer is shutting off the compressor then you need to know why. If the pressures are building up that high then you may have a blockage( i.e. expansion valve) somewhere. You need to see the pressures on a gauge first to determine what is happening. Jeff

266

Hi Ken, Yes they could but doubt they are related to the vehicles A/C system. With anything electrical, you always start at the fuses and relays. Check for any of them that are burned or not working. Look for aftermarket connections made for the retro fit job. As far as the low side pressure, 30 is a good number. Jeff

267

Hi Tim, If you have replaced three compressors then you make have a blockage somewhere in the system. Did your high side pressures exceed 400 psi. As far as the add on is concerned, I would consult Ford on the compressor you are using to find out if it is compatible with your application. Jeff

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Sheldon Altschul
June 26th, 2011 at 5:19 pm

Jeff,

Thanks for your response. The high side was normal when it was in the shop. The lines and the evaporator are not icing.

Is it not possible that the thermostat is not cycling the compressor when the cooling demand is met or does it not work that way? There must be something I don’t understand.

Shel

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Hi Sheldon, you may have a faulty cycling switch. Jeff

270

Hi Jeff,

Thank you for a very informative article. I am about to attempt replacement of my comp, receiver drier, condenser and orifice tube on my 2000 Ford F150 5.4.

A professional shop I paid to look at it since it stopped blowing cold last month said they found no leaks and the comp. was starting to make noise. So after a evac of the system they checked the orifice tube and showed it to me. There was a few bits of dark material near the top on the screen. It didn’t exceed 1/8 inch on the tube and the rest was clean. They said I caught it early.

His recommendation was to r/r the compressor and receiver, flush the system and fill. Amount $1087.00

My question is will I need to flush the system as the mechanic wanted to do since I will be changing out the condenser? I will be buying all new Motocraft parts. Cost 497.20 delivered.

Also if you can think of any suggestions please feel free to add.

Thank you in advance, Dwayne

271

Hi Dwayne, I would not recommend flushing the evaporator since it is difficult to remove all of the flush but on straight lines it is ok. Check the oil in the compressor. If it looks like silver paint, then you may have to replace the evaporator but do not flush it. Other than that you are rebuilding the system I would check the hoses as well. If they need replacing, now is the time. Tell the shop doing the repairs to use double end cap PAG oil. It is the best. Jeff

272

Jefff

I have a 99 dodge grand carevan with a 3.3l engine.
and i am courious. what causes the cooling fan to come on when the AC is on and the engine is cool to cool the condensor.

273

Hi Mike, When the A/C is turned on at the control head, a reference signal is sent to the PCM and it converted to an output signal that activates the relays for the fans. Jeff

274

Jeff, i have a 2004 Nissan xterra. we had the a/c vacuumed and re-filled about two weeks ago. i have not noticed anything leaking, except water from condensation, but now it is blowing warm air. I am getting ready to check all the o-rings and seals now to find something. know anything that might help on the Nissan xterra’s? Oh, and while at the parts store they had a few “stop leak” cans with fron and oil mixed for around $30. not a fan of the stop leak, just a gut fealing i have, any thoughts?
thanks for your time and help.

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Hi Jason, If you are going to charge it yourself then make sure its the exact amount. The capacity label is in yellow and black under the hood. As far as a leak goes you can use freon that has dye already mixed with it or you can purchase a sniffer. Either way you should find the leak before going through all of this again. If it is a compressor leak then you will need to replace the compressor. Stop leak is not recommended but if you cannot find the leak or it is to difficult to repair then it is an option. Jeff

276

Hi Jeff,

Thanks for all the great information on your site. My girlfriend bought a 2002 Dodge Durango. It has a dual zone system with the rear air. The a/c was cool but not cold. She added a 13oz can of r134a with 2oz of sub zero booster for a total of 15oz. Afterward the ac was only blowing cool intermittedly with the compressor engaging and disengaging every second or so when really hot outside. Ambient pressure with engine off was 100(with low side slightly higher) at 85* . I checked the pressures with doors open, front ac on full and rear ac on full cool, low fan and low side was reading 40-45 and high side 225-250 at 85*. The center duct output was 65* after running a few minutes. The lines were cold(no frost) and hot. I was getting lots of condensation under the front and little from the back. I’m wondering if it’s overcharged or whethter I have another issue?

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I also forgot to add that these pressures were at idle 750rpm. The rear air is running about 10* warmer than the front. I also noticed that with both a/c units on full cool/high fan that the pressures are running about 50 low side and 250-300 high side at right around 90* air temp outside. Thanks for any help.

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I have a 2004 Ford explorer the low side is high and high side is low everytime the compressor kicks in the pressure jumps. Could it be the reed valve and how do you fix the valve.
Thanks for any help.

Steve

279

Ok… I feel like an idiot..
I recently got a 2006 Suzuki Aerio from my dad for a good deal.
The AC would blow fine while on the frewway but barely worked at idle.. I bought some R134A with no gauge, over charged the low side by way too much… the serpentine started smoking and the making a bunch of noise… shut the system down… went and bought a large can of R134A with a gauge.. dropped the pressure down to the “filled” blue section… now my compressor makes a grinding noise for a few seconds then quiets but only blows hot air….

I plan to take it to a shop but I dont want to get ripped off.
The AC light comes on but no air what so ever… A new compressor is $1500 which I do not have… So do you think its more than likely a clutch issue or did I just blow out the compressor?

It was in the red section and was reading around 120 psi before I brought it back down…

280

Hi Jeff,

I have 1999 , 2.4 plymouth voyger , my AC is leaking some where
i put the freon and then i drive 17hour , very nice cooling, but when i park over night my freon is leaked, can u tell me where is he problem or i how i can fix my Car or where can i find the leak, please let me know. Thanks

281

my 1994 Toyota Corolla (200k miles) ac failed..first we replaced the valves,H and L, as one appeared to be leaking..lasted 2-3 days then failed..hen we replaced the O rings on both lines..ac worked great for 2 weeks..again failed..we used a ‘sniffer’ and the compressor appears solid..no apparent leaks anywhere..it is a mystery..

what to try next?

don

282

I have a 2004 Mitsubishi Galant. My air was blowing a little warmer than I would like so I added some freon. When I got back in the car it was blowing hotter than before the freon was added. Do you have any suggestions on how to fix it and or what I may have done. Thanks,

283

I have a 1998 S-10, replaced the AC compressor 4 years ago, evaporator, accumalator and orifice tube, in short everything but hoses. In the last few weeks the AC has gotten to the point if I’m not running down the road at 55 mph the compressor won’t kick on but if I stop somewhere and wiggle the plug connection at the high pressure switch it will take off. When it’s runnng she’ll freeze you out

Starting today I’ve noticed the compressor once it’s started (either cause I’m running down the highway or started it by wiggling the connection at pressure switch) will run for a short time and stop working. Now it seems like it is kicking out for high pressure but before I was thinking maybe the pressure switch was bad or a short in it or at the plug on the wiring harness. Plan to get it checked this weekend but I am curious for your opinion on the matter or where might be the best place to start looking.

284

Hi Kevin, Dual climate control systems are hard to diagnose due to there being two of almost everything. Your pressures seem a bit high. I would evacuate the system down to 28 in hg and recharge the system as close to OEM as possible. Then watch your pressures again. Use water on the condenser to when transferring the freon. It will flow faster to the system. Jeff ( Please don’t forget to C-L-I-C-K on all the A-D-S-B-Y-G-O-O-G-L-E as this is how we keep this web site running. Jeff )

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Hi Kevin, Pressures are too high.

286

Hi Steve, A bent or damaged reed valve could cause this and can not be fixed easily. Most cases the compressor is replaced with a new one. Not Re-man. Ford used a Scroll compressor on that year I believe and I would go Dealer with the replacement. Jeff ( Please don’t forget to C-L-I-C-K on all the A-D-S-B-Y-G-O-O-G-L-E as this is how we keep this web site running. Jeff )

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Hi Brian It sounds like you drove your head pressures so high that it damaged the compressor. With the engine off and the compressor COLD try to spin the compressor by hand ( not the outer puller ) and listen for grinding or metal sounds. Compressor new are about 3 to 400 and if the where heavily damaged then the condenser and accumulator?drier needs to come out as well. Jeff ( Please don’t forget to C-L-I-C-K on all the A-D-S-B-Y-G-O-O-G-L-E as this is how we keep this web site running. Jeff )

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Hi Farooq, The easiest way to find a freon leak is to look for signs of fresh oil. Freon and PAG oil travel together so where there is a leak there will be oil unless the leak is so minute or slow that the oil ( being heavier ) is left behind in the system. Dye injection or heated Diode sniffers are how most shops find the leak in a system. Jeff ( Please don’t forget to C-L-I-C-K on all the A-D-S-B-Y-G-O-O-G-L-E as this is how we keep this web site running. Jeff )

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Hi Don, I assume that you are pulling a vacuum on the system each time you recharge it after the repairs. If you have a ‘ sniffer ‘ then try under the dash by the evaporator. You will need at least one pound of freon in the system to do this. Jeff ( Please don’t forget to C-L-I-C-K on all the A-D-S-B-Y-G-O-O-G-L-E as this is how we keep this web site running. Jeff )

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Hi Chad the misconception is that if a little freon is cool then more freon must be colder when in fact too much freon will make a system run warm. Without gauges it is difficult to know how much freon is in the system. You may have to take it to someone who can tell you what the pressures are before you can move forward. ( Please don’t forget to C-L-I-C-K on all the A-D-S-B-Y-G-O-O-G-L-E as this is how we keep this web site running. Jeff )

291

Hi Jeff Your High pressure Transducer may be at fault but more times then not it is a poor connection at the pigtail. If you can disconnect the pigtail and look for signs of fraying wires or missing insulation. If you have a Multi meter run a continuity teat on the connector and wiring harness. As far as the Transducer is concerned I would replace just to be safe. Jeff ( Please don’t forget to C-L-I-C-K on all the A-D-S-B-Y-G-O-O-G-L-E as this is how we keep this web site running. Jeff )

292

hi how are you doing i have a serious question my ac works blows cold air but when i put it on max ac it does not blow on my face but only on the windshield which does not cool the car can u please help me out if u no what this may be from thank you

293

Thanks Jeff. Now it was just my morning drive and by noon today here in Louisiana it will probably be a heat index over 100* but for some reason my air actually blew cooler than yesterday. I eventually had to turn it down b/c of how cold it was. Is it possible I have a leak and over filled yesterday but overnight it leaked out causing pressure to go down. Thanks for the help.

294

Hi Mark, depending on the type of vehicle you are driving it could be the control head itself or a vacuum leak ( Ford ) in the lines that run to the actuators that control flow routing ( i.e. blend doors ect. ) Jeff ( Please don’t forget to C-L-I-C-K on all the A-D-S-B-Y-G-O-O-G-L-E as this is how we keep this web site running. Jeff )

295

I’m having a problem with my air conditioner in my truck. Its a Dodge ram 1500 4×4 and there are no leaks that i can find..its got plenty of freon but it cuts out..the blower still blows but the air gets hot. I can cut the air conditioner off for 5 or 10 ten minutes and cut it back on and it works for awhile but then just cuts out again..the compressor isn’t freezing up it just kicks out, although iv had it checked and was told it was fine. it seems like it works better at night but at times its still sporadic. Is there some kind of sensor that could be going bad or something? I cant find it if there is. Today I was sittin at a redlight and it was working fine but the minute the light turned green and i took off it cut out. I’m at a loss.

296

I have a 1995 mustang 5.0. The AC works very good but not all the time. I could be going to work when its about 77 degrees and it will be cold right away our not at all there is no working and then not getting cold it either blows cold air or hot and stays that way until maybe the next start up.When I get off work the same thing when its about 95 degrees but it seems to work more often in the mourning. Any info would be appreciated.

297

i have a 2000chevy express van 3500 the air blows on feet not vents canynt figure it out.can u help mr please’johnny

298

Hi,

I own a 1999 2.2 liter Chevy S-10 pickup regular cab. I have had problems with my AC unit blowing semi cold air for two summer seasons now. I have had it charged twice and checked for leaks both seasons and it blew cold air for a while but now it just blows cool air. It takes 15mins for it to get semi-cool and it makes a chirping cricket noise when its turned on. What might my problem entail?

Thanks Shane

299

Jeff, great information. I have a Ford Focus. On normal days, like 75-85 degree days, the AC works great. On really hot days, above 90 degrees, the AC will blow warm air. What could be the possible diagnosis to this?
Thank you. Stay cool!

300

Hi Jeff, thanks for your help for us DIY people.

I have a 2005 Chevy Uplander with dual a/c. The a/c was fine but began making a “marbles in trash can sound” with the a/c compressor engaged. Eventually the compressor locked up. I can’t turn it by hand. I have a new compressor and new condenser/drier (condensor component also has a receiver/drier bolted installed with it). I will ensure I have 4 oz of oil in the compressor and add 2 oz of oil to the condensor/drier components.)

I haven’t planned on replacing any of the expansion valves or flushing any components except for the lines leading to the compressor, condensor and the line to the front expansion value and blowing them with air.

Since its a dual a/c, is there anything else I need to do? I plan on vacuuming for 30mins; test for leaks; and recharge while holding the low pressure 30-35 and high at 2.3 x ambient temperature. I plan on setting the rear a/c on low fan speed. Thanks Jeff.

301

Hi jeff, i have been doing ac work for a while, and have learned alot. except the fine tuning or diagnosing. i am doing the ac on a 01 f350 with a 7.3, the customer brought it in saying it would blow cold and then warm up after a while. so i thought the fan clutch might be weak, or the condenser might be clogged up with bugs. so the fan clutch was working great, and i power washed the condenser and between the raditator and condenser all seemed nice and clean, you could feel the fan sucking the air through the rad and condenser. so i was thinking the orfice tube might be clogged, so i opened the system flushed the evaporator core for 30min and then blew dry air through it and then added 1oz of oil to it. flushed all the lines really good, replaced the condenser and the accumalator and the orface tube. added 2oz of oil to the compressor and sealed the system up. after vaccuming the system down for 30min and letting sit, and no leaks. i added my freon. just wonderful, blowing out about 45degrees. but after running and driving for a while it warms up!!!!!

302

Hey Jeff….I have a question in retrofitting an AC system…The threads are a little worn on the low pressure port. In putting on the new retro port can I just remove the guts of the original low side port and then screw the retro port on? Of do you have to have the low side complete?

303

Jeff,

Last summer I added 1 can of freon 134a to my 91 Dodge Durango. It worked fine. This summer I added 1 can 134a because was not cold enough, but the air goes from cold to warm. The gage indicated that it was low based on the out side temp. So I added a second can and I noticed that the Compressor Clutch was engaging and disengaging. When it engaged, I felt the can get cold and when it disengaged, the can became warm as though the freon stopped being dispensed. The clutch is presently engaging and disengaging. When I start the truck, I can hear the Clutch engage on the first cycle only from inside the Cab.

Where do I start with my investigation?

Great Site, I will click as instructed.

Thx, Jim

304

Hi Jeff;

I have a 98 Chevy Astro Van with rear air. The system had a leak due to a crimped hose connection rubbing against the trans fill tube. The system hasn’t run in over a year, and I’m replacing the receiver/dryer plus replacing the 3# of R134a – my question is: How much oil do I put in the system?

305

I have a 1994 Jeep Grand Cherokee whose AC is not blowing cold air.
The system is properly charged; the compressor is cycling; the low pressure line entering the firewall (evaporator ?) is cold and the other line coming from the firewall is warm. What gives?

306

Wife’s 2002 Cavaliers compresser was cycling on and off. I jumpered the cooling fan and it works ok. Tried adding a little freon but it didn’t seem to take much if any. thenn comperssoer was blowing off the pressure relief valve. unplugged then plugged high pressure sensor back in and now the ompressor will not kick on. i’m thiinking it;s got something to to with the cooling fan not coming on with ac. could maybe be temperature sensor? Thanks in advance.

307

Hi. I have a 1996 Chevy Extended cab PU 4.3 Litre. We have replaced the freon with the 134 a. The air coming out seems cool, but it is not blowing very hard like it use to. Can you give me some advice ? Thanks.

308

P.S. We did use a gauge and it showed that it was the right amount.

309

Hi Jeff, I’ve got a problem with my a/c. My compressor turns on then decides to turn off whenever it feels like it. Then turns on again after while like 15 – 20 min. I recently replaced everything in the system from the compressor to the orifice tube, accumilator, and a few valves in the service ports that where leaking. Worked fine but after a few weeks it started acting up. I checked the refrigerant lines to see if where leaking or losing freon but looks fine I also hooked up my hoses to see what the pressure was and it was at alert around 65. Over the filled marker on the gauges could that be a problem and if not what else can it be.

310

Jeff;

I have a 1990 Eagle Talon TSI since new; the a/c has always been really cold until last year when my compressor failed. I was told that R12 was no longer available and that I would have to convert to 134.. which I did at GREAT expense.

The conversion included all components save the connecting lines and hoses. I got the car back last week and to my chagrin, cools.. but only to around 60 degrees; that does it cut it when the temperature is 95+. I took it back to the shop and they tested for leaks again and found the system functioning properly (?)

After reading your article above, might my problem be that the replacement condensor is the original R12 type and not the paralle flow?

Question: Could you obtain such a condensor for me?

Question: I have been reading about Ice 32 and another product called ICECOLD. Would either of these help and do you sell them?

Thanks in advance for your counsel.

Desparately seeking solution!

RJS

311

Great article on AC. Question – I have tried several times to send a follow up question regarding AC and when I press submit – I get a prompt that says I did not answer the challenge question correctly. I see no challenge question anywhere on your site so am confused by this prompt. Should I submit my question at this comment section?

Thanks.
Frank B.

312

To save time – I will copy/paste my question here as the “contact form” prompts me with “I did not answer a challenge question correctly”. I don’t know what that is about but here is my question and thank you very much, Jeff.

Hello Jeff. I am wanting to run a pressure check using the low side AC service port on my 2006 Dodge Ram 5.9 Diesel. Only problem – I can only locate two ports – one a small one which my pressure hose fits – but this port sits on the evaporator cannister next to the firewall and measures 150 lb. so that has to be the high side port. The only other port is left front of the engine next to radiator – this port is on the larger line but the port is larger than the standard hose coupler which has fit other low side ports on vehicles I have added refrigerant to. I called Dodge and they confirmed the low side service port on their vehicles is a standard fitting. So, my question is – where the heck on my engine is the low side AC service port where refrigerant can be added. Thank you.

313

Heyy Jeff question do all cars need a condenser

314

HI Jeff: I have been searching for info on my odd puffing. When my AC is on it seems to make an occasional puff noise (approximately ever 30 seconds or so, not regular). The gauges don’t indicate a change in anything, but I think I feel a slight reduction in the cars power when it happens. I have a 99 Subaru Forester with on 75k miles.

315

Hey Jeff… My AC was working pretty good, buddy said it could be better so he tried charging it up. Now the AC doesn’t work and blows full hot all the time. He thought maybe over charged so he tried sticking a screw driver in the low pressure port to drain some out, but it was like there was nothing to drain out? 113 heat index today, need my AC back

316

Hi Jeff,

I have a 2003 Isuzu Rodeo – never had A/C issues before but recently my A/C was blowing cool (not cold) and just intermittently. I figured the r134 was low so I grabbed a few cans and filled it and it seemed to run cool again, but that was when the days were cooler/warm well now we are in the heat of the summer days and what is happening is the air will blow cool for a few minutes (maybe 10) then it will start to blow warm, I turn the compressor off for about 5 min and then turn it back on and then it blows cool again. And this happens over and over until I just give up and drive with the windows down. Here is the rub though in the mornings and the later evenings (sun down) it will blow cold continually with not stopping and starting? I am at a loss is my lines freezing up? What would cause it and what can I do to fix it? Thank in advance for any advice.

317

Oh, and I forgot to add that I had an local A/C service look at it (and of course it was blowing cool for them) they said the pressure was fine, the hooked it up to the gauges to check. So pressure is supposedly fine but still intermittent blowing on hot days??

318

hi jeff…… quisiera saber si puedo colocar un filtro universal el la linea que sale del condensador de un malibu clasic 83…. la idea de esto es que este filtro recoja las particulas que salgan de condensador y mantenga la valvula de orificio libre de sucio, es lo que yo pienso pero no tengo experiencia en el tema…. espero su pronta respuesta…..

319

Hi I have a 1998 Chevy blazer and the AC hasn’t been working, my dad added more freon to it and it worked ok not great for like 3-4 days and now hasn’t worked since. When I turn it on it just blows HOT air not even cool at all. Thanks in advance for any help you can offer.
Yaala :)

320

Jeff,

I really hope you can help me with this; I had the compressor replaced in my 2004 Audi A4 last summer after it ate itself alive. After replacement, the new compressor drew so much power from the vehicle that it would slow the car down (as if gearing down) as I came to a stop. Along with the drawing of power came a very loud hum (groan) which silenced instantly when the AC was turned off, and a vibration you can feel in the pedals. Also with the AC off, the car operated fine. I returned to the shop, and they reluctantly replaced the compressor with another, as well as a new tensioner; however, the problem persists to this day. It is probably also worth mentioning that the belt tensioner (both new and old) bounces crazily with the AC on, and I have lost about 10 MPG since the replacement (I actually regain this if I’m not using AC). Thank you so much for any input you can give.

Rod

321

Hello Jeff.hope all is well.I am so frustrated. I have a 2ooo Honda Accord coupe.I changed my compressor since it got burned. I also replaced the drier.and pressed and changed a hose since it had a leak. after flushing the system and adding freon to it.I then noticed I had a leak in the high service port ( black or red cap ) so the mechanic tried changin the valve but the leak was still there. So I had to get a new pipe with the service port since their one piece.after doin the job. I checked my car and it seems I have another leak on top of the drier.where the the new pipe is connected and also the pipe next to it.it seems their both leakin but slowly.service pipe port seems to be leaking a little more.it seems every time I fix a leak another pops out somwhere else.also a sound comes when I turn the AC on..its like a clicking sound. I started hearin it after he replaced the pipe. Is there a possible way to seal the these small leaks on the connection of the servive port pipe and the adjacent one. And can you tell me what is making that clicking sound.thank you in advance.and god bless for the help you are giving to the people.take care.

Ahmed

322

Jeff,I have a 97 vw golf and in the morning(when it is cool)my a/c works good but in the evening(when its hot)my compressor will turn on then off every 2-3 seconds causing my car to feel like it has a very bad miss.Would this be high head pressure and if so how would i fix it?

323

Hi jhurtado, Yes you can put an inline filter on the high side but I would recommend putting it before the condenser. Jeff

324

Hi Ahmen, yes they do make a stop leak for a/c systems and some of them do work but I would recommend fixing the leak because you are risking plugging the condenser. The clicking sound cold be coming from your compressor and I would check the pressures ( i.e. overcharged) They shop that is performing the repairs should be leak testing after each repair. Jeff

325

Hi Aub, make sure the fans are coming on and if you can check the pressures. That will tell you a lot. It does sound like the pressure are climbing high enough to trigger the pressure transducer on the high side. Jeff

326

Hi Rod, Anytime a compressor fails I would recommend changing out the condenser with an OEM due to the fact that all of the guts from the compressor go straight to the condenser and no amount of flushing will get it out. It sounds like the compressor is under high load either due to over charging or a plugged condenser. A pressure test will reveal this and the shop should know this. jeff

327

Hi Yaala, If you had to add freon to the system, then chances are you have a leak. Have the system leak tested with a pound of freon in it. If the leak is coming from the compressor housing or front seal, them replace the compressor. Sign of fresh oil on hoses and lines are an easy give away of a FREON LEAK SINCE OIL AND FREON TRAVEL TOGETHER. Jeff

328

Hi I have a couple questions first is it bad to blow shop air threw the ac lines, evap, and condenser? Also friend has a 95 Lincoln towncar they over charged the system which made it blow warm air. However I Vacumed the system and then re added the correct amount of freon the car is blowing nice cold air however once u give the car a little gas the compressor kicks off then back on repeatedly not real fast but at a idle the clutch stays engaged. I jumped the low press switch n it didn’t kick on and off so I thought bad switch bc the pressure on the gauges didn’t drop below 20 on the lowside however it still does this with the new switch what could b causing this and also the compressor is on it’s way out(can see red/brown) on the clutch if the compressor goes what all should b replaced I see u don’t recommend flushing them cause it’s not poss w a parallel unit not sure if the Lincolns is a parallel or tube fin. Anyway if u have any insight on what the problem could b or if this is normal thanks

329

Hi Gary, yes you can blow shop air through the lines ( flush for straight lines and tube and fin condensers ) just evacuate a little longer to get the moisture out. Your pressures on the Town Car should be Low- 22-47 and High 160-245 and you should have 2.13 lbs of freon. If these are your specs and you still have a cycling issue then its time to check other areas. If you replace a blown compressor then replace the condenser, orifice valve and accumulator. Its worth it. Jeff

330

hi i have a 2001 dodge stratus with 35 to 40 psi freon range ac compressor runs but no cold ac. control from heat to cool works fine hot heat with car warmed up but ac is slightly cool not cold.

331

Hi Jeff,
Have a 2006 Chrysler town& country. Compressor, I think, made loud screeching sound, then hot air. I hear a clicking sound when I turn on a/c. Can also smell strange odor. Also, if the compressor fails, will it still spin or will it stop and burn up belt. I think there is only one belt. Worried about driving it if there is a chance it could cause other engine problems. Thanks in advance!

Jim

332

Hi Jeff,
im so happy to have this chance to get an advice from expert like you,

i have infiniti FX45 2003 model, when i switch off my car for more than 2 hours the AC is not working at all (very warm air), once i drive car for 10 minutes on high way or by keeping rpm over 4×1000 suddenly ac is working perfectly very cold ,
it will be like this till i switch off car for 2 hours again same issue,
i have asked for advice but all are advising to replace all parts which its quite expensive,
any advise?

333

so, do i have to check cut-off sensors or stuff like this?
or maybe i can change basically one part ?

334

Hi Nadi, check to see if the cooling fans are on when the a/c is switched on. Make sure nothing is blocking thew condenser and then with the a/c on and engine at idle check the compressor. Is it cycling on and off quickly or with long intervals. Jeff

335

Hi Jim, your compressor may be on its way out . As long as the a/c is off the compressor pulley should freely spin. With the engine cold and OFF ( not running ) try to spin the compressor by hand if it is locked up or excessively hard to spin then you need a new compressor . Jeff

336

Jeff,

ok , the ac will be on off quickly without any delay (after working properly),
how can i check if condenser is blocking or not?

337

Hello Jeff,

I was wondering if you could help me out with this:
I have a 1998 Pontiac Firebird Trans Am.
Ever since I bought it, the A/C system has always blown very little air(I have it on High and it feels like it’s on the lowest level). I have taken it to two mechanics who tell me that nothing is wrong with it. I oppose since I have been in other Firebirds and theirs always blows much, much more air than mine does.
I have no problems with it blowing cold/hot air, just that it blows very little. Not enough for me to actually use it in the blazing summer heat.
I have replaced the compressor since it had been making a lot of noise, and the mechanics tell me that nothing is wrong with the blower or vents.
I have, however been told that it might be the evaporator core? Could this be the problem? I think they said that there was no condenser on the car? I just want to get advice from an expert.
Thanks in advance.

338

Jeff,

I have just purchased a 2000 Chrysler Concorde. The AC blows but not cold. The man we purchased the car from said that he had put in freon previously and the air blew cold for an afternoon and then went back to just blowing air so he is assuming that there may be some type of leak. How would I go about getting something like this repaired? Could it be something more serious than a simple leak? And what should I expect in terms of cost on this repair?

339

Hi Jeff , thank you for helping people . My neighbor has 99 chevy suburban . when A/C(car on also) on ,It blows cold for 10 seconds then blows out hot .What could be the problem?

340

my 2003 land cruiser AC it started making clicking noise from the dashboard and some other times the air gets blocked half way and it gets released again, this happens every few seconds and sometimes it just gets blocked the whole trip. I have played with the switches and they turned out to be fine. This has been happening for the past 3 months, the local agent so far can not figure out the problem. Hope you can help.. Thanks!

341

Hey Jeff,
The A/C in my 1994 525i went out the other day. Worked great one day, not a spec of cool air the next. My first thought is that the refrigerant needs to be recharged. I use to do this to my Mazda truck. I did my research, have the correct refrigerant(R-134a), my tester gauge, found the low side pressure port. Started the car, turned A/C on max and tested with gauge. Sure enough nothing registered. Then got the refrigerant and started to fill. In no time a foul smelling “smoke” (for lack of a better word) started coming up from the passenger side front corner. Of course I stoped immediately. Smoke continued to come up. I turned off the A/C and smoke stopped. Turned it back on and smoke started again. So I am thinking ok, it must be a busted hose or something and that is the refrigerant leaking. Then I noticed a green liquid dripping on the pavement underneath the passenger side front and I hear a hissing sound from the same area. I asked myself “is that antifreeze?” But I use the BMW coolant which is blue.

Did I just kill my car?

Thanks,

Kristen

342

Hey jeff just like to say thanks you for taking your time to help all of us. I have a 97 dodge stratus 2.4 compressor went out so if went ahead and changed it along with h block and drier. I filled her up with freon and everything seemed fine got to the freeway and tpok off and started blowing hot air went back home hooked up the gauges everything seemed normal readings no leaks went back out stopped again this time if noticed compressor was fighting to try to stay on so hooked up gauges and still fine so went home recovered a bunch of freon out of the system after readings some of your posts from phoenix always tjought it should be around 45 or more if dropped it to around 35 on the low it seems to kinda help with thecompressor staying on but now when if run her up to about 2500 for a bout 45 seconds clutch will disengage and only way ive found to get it going again is flutter the gas erratically and it will engage again it is a reman compressordoyou think it could just be a bad compressor prob or condenser or maybe a relay? All if know is im kinda stumped and leaning towards the reman compressor any insigyt at all would be much appreciated

ThxDavid

343

Hi Jeff,

My Honda Civic A/C blows less cold air. In other words, the cooling is not enough. Should I recharge or the issue might be some thing else.

Please let me know your thoughts on this problem.

Thanks
Raj

344

I WAS WORKING ON MY SISTER\’S 1986 CHEVY CELEBRITY 2.8L V6 FI TRYING TO FIX THE COOLING FAN, WHEN I NOTICED THAT A WIRE WAS DISCONNECTED FROM SOMEWHERE. AFTER SEARCHING I FOUND THAT IT WAS SUPPOSE TO CONNECT TO THE BACK OF THE AC COMPRESSOR BUT THE PART THAT IT PLUGGED INTO ON THE COMPRESSOR WAS BROKEN OFF. THEN I MADE A MISTAKE, I REMOVED THE CLIP HOLDING THE PART IN PLACE & THE COMPRESSOR BLEW OUT PRESSURE & I DON\’T EVEN KNOW WHAT ELSE, FREON I AM GUESSING. I FINALLY FOUND THAT THE PART IS THE Compressor Mounted Cut-Out Switch. HIGH OR LOW, I DO NOT KNOW. MY QUESTIONS ARE… ONCE I REPLACE THE PART, WHAT DO I NEED TO HAVE DONE THE THE SYSTEM? JUST ADD FREON? OIL? HOW DO I KNOW WHAT KIND OF FREON THE CAR NEEDS? DO I NEED TO PULL A VACUUM? CAN I JUST ADD FREON FROM THOSE CANS YOU GET AT AUTOZONE WITH THE GUAGE ON IT? ALSO, THE PART HAS BEEN VERY HARD TO FIND… IF I REINSTALL THE OLD ONE, HOW DOES IT AFFECT THE SYSTEM, NOW HAVING THAT PLUGGED IN LIKE IT IS SUPPOSE TO BE? THANK YOU SO MUCH IN ADVANCE FOR YOUR HELP, THIS HAS BEEN A SMALL NIGHTMARE!!

345

The A/C on my 2005 Chevy Cavalier is working fine until I have to stop at a traffic light or go through the drive through. It still blows the air but it is very hot. Once I start moving again, it goes back to normal cold air. Any suggestions?

346

Hey Jeff the A/C in my 1999 Sebring convertible only works on high and blows cool. My dad tells me it’s not my compressor but, I’m about to make a trip to Arizona with a 1 year old and I desperately need the air to work. Any ideas as to what could be wrong?

347

Hi Kearston , If the air only blows on high and no other setting then the resistor block may be bad . Without looking at the pressures it is hard to tell why it is not blowing very cold. Jeff

348

Hi Terri it sounds like you may want to check your condenser fans for operation. Make sure nothing is blocking the condenser. If you can check the pressure, that will tell you a lot. Make sure the engine is not over heating. Jeff

349

Hi Raj, Honda Civics have very small condensers and the freon charge has to be right on the money with them. The pressures will tell you if the system is under charged. Also if the compressor cycles to fast is another clue. jeff

350

H David Anytime you replace a bad compressor the condenser must also be changed. Jeff

351

Hi Lisa, anytime the system is opened you must evacuate it with a vacuum pump for about a half hour, then introduce freon to it. Jeff

352

Hi Jessica, Yes you do have a leak but now you need to know where and that will tell you how much. Compressor front shaft seal leaks and evaporator leaks will cost the most. Dye testing or a sniffer will work . If you cannot do the test then take it to someone you trust. Jeff

353

Hi Mari, First thing to check is the vent doors and check to see if air is coming out of the defroster. The blower motor itself may be defective and yes you have a condenser. Jeff

354

Hi Jeff.

I have a 2003 Dodge Stratus that just the past few days has blown freezing cold like it should, or just plain air (outside temp). Often it will work for a bit, then after I stop to shop and get back in, it doesn’t blow cold. NAPA guy instantly told me my compressor is blown (it never chattered or made a sound) and will cost $1300 to fix. I’m cringing at the thought of the rest of the Georgia summer with no AC! Is it possible I’m being taken for a ride?

355

I made a donation, I wish it could be more!

356

Hi Sarah , Thanks for the Donation, we Greatly appreciate it. Jeff

357

I took it to another mechanic on the advice of a friend, and it was low on freon. $20 and blowing cold. I was totally being taken for a ride by the first guy. Sad thing, it was an ASE certified, NAPA auto shop. Crying shame you can’t trust people! My friend told me it really depends on your gender when you go to that shop – the owner consistently rips women off. Glad I got a second opinion!!

358

Hi Sarah, I would recommend having the pressures checked first. This will tell you a lot. Always get a second and maybe a third opinion. Try to find a shop that you trust and is certified to do the work. Most compressors will make a rattle noise as the begin to fail so you may have an issue with freon levels or possibly a defective switch. Once again the pressures on the low and high side will tell whats going on inside the system. Jeff

359

Hi Jeff!

Yes, I’ve had compressors go out in the past and there was ALWAYS early warning in the form of a chatter or rattle. There was none of that in this case, which is what really made me feel that wasn’t the problem and I was being taken advantage of. The low freon appears to have absolutely been the issue – I have driven it several times today and the AC is blowing cold like a champ.

This column was very helpful to me in that I went into the second mechanic’s shop armed with much more knowledge and possibilities of what it might be! Keep up the good work. I am bookmarking you for future reference and will share you on Facebook as well!

360

Jeff,
My post from 2 days ago somehow disappeared even after I donated… I’ll try again, I have a 2000 Jetta TDI and had it in the shop several times for the AC. My problem is my AC works fine for 15 to 20 miles then it stops blowing thru the vents. Kinda sounds as tho it’s blowing somewhere else but if I turn the AC off and let it blow on re-circulate for a couple mins and put the AC back on, it works fine and does the same thing and stops blowing. When it works, it is COLD. One problem was I was getting a whistling sound then it sounded like the AC was gonna blow up. The mech. changed the expansion valve I think it was and the noise went away but still have the original problem. The fan was also changed. It’s driving me nuts and broke trying to figure this thing out. Please help!!

361

Hi Mark. It sounds like your blend doors may be at fault. When the air stops blowing from the front vents check to see if the air is coming out of the defroster. The servos or actuators can sometimes be defective or the control may be sending the wrong command. A bi directional scan tool can check the climate control system to check for fault codes and to command the blend doors to check for issues. Jeff

362

HI JEFF. I POSTED A COMMENT ON 9/7 @ 4:54AM. YOU ONLY ANSWERED ONE OF MY QUESTIONS ON RESPONSE. YOU SAID I WILL NEED TO EVACUATE WITH A VACUUM BEFORE ADDING FREON, BUT…
HOW DO I KNOW WHAT KIND OF FREON THE CAR NEEDS AND HOW MUCH? CAN I JUST ADD FREON FROM THOSE CANS YOU GET AT AUTOZONE WITH THE GUAGE ON IT?
ALSO, THE PART HAS BEEN VERY HARD TO FIND… IF I REINSTALL THE OLD ONE, HOW DOES IT AFFECT THE SYSTEM, NOW HAVING THAT PLUGGED IN LIKE IT IS SUPPOSE TO BE?

363

Jeff I have a 98 surburban and here recently my air in the back blows but its warm air. My air in the front will freeze you. Can you tell me whats causing this?

364

Hi April, On rear A/C systems, you have two evaporators and two orifice valves. I would check the orifice valve first to see if is clogged. Jeff

365

Thanks Jeff. I will have someone check that out.

366

please help!!!

367

Hi Blaine, The first thing to check is the pressures. For that you will need a set of gauges or have someone do it for you. Also check the fan clutch to see if is operating properly. Is the vehicle overheating ? Jeff

368

Hi Jeff,
I was wondering if you can help me with this problem I am having with my ac. When my car is on and is on park, the ac gets hot, but when my car is going on the road, it gets really cold. It’s been like this for over a month or two already. We already changed the fan, added freeon, changed the radiator, but the problem is still the same. Why is it that the ac gets hot when I am parking, and when I am driving it gets cold again and then when i park it starts getting hot again in less than a minute. I would really appreciate any input. Thank You

369

Hi Resa, The first thing I would check is the pressures. That will tell you a lot of what is going on inside the system. Without that info I might say you may have a clogged condenser , plugged orifice valve depending on the type of vehicle. Once again the pressure test will tell you this. Jeff

370

sir my car is nissan sentra what will i check if the switch number 1,2,3 is not working but the switch number 4 is very cold

371

Hi bhines, depending on the vehicle I would check the resistor block. Most of the time they are located inside or on the blower motor. Jeff

372

I have a 2005 V8 Lincoln LS with approx 33K miles. For last 3000 or so miles the air conditioner seems to make what I can describe as a gurgling sound from the dash. This doesn’t happen all the while the ac is running but only intermitently. The car is cooling just fine but am concerned that this noise is an indication of a future problem – - one that a little preventative maintenace would fix.

I have an extended warranty with Ford and I’ve pointed out to the dealer that I hear this noise. They said the tech did not hear and the air cond is fine.

Any thoughts on what is going on or what is wrong? A big thanks!!!

373

Hi Joan, It sounds like you might have an air pocket in your heater line that feeds the heater core. Check your engine coolant levels . Also make sure your engine is not running hotter then usual. The sound you hear is from air bubbles rushing through the heater core lines that feed the heater core under the dash. Jeff

374

hey jeff,
i have a question i live in florida it is cold out tonight and when we were driving my 2003 hyundai elantra of course i had the heat on and the windows were foggy. so i cut on the A/C to defog the windows and cool sort of warm air was blowing out not cool air. then about a hour later my husband took the car to the store then called me and said the car was smoking i gues he had the ac on. so i dont know if it needs to be filled with freon or not i think it do i just dont know what the smoking was. if i need freon how many cans.

375

Hi Michelle, the first thing I would ask is where is the smoke coming from and was there any noises or sounds associated with it. Can it be recreated and how long does it last ? Jeff

376

hello

you r v knowledable. i have 1 question.

my ac is cold bt onlt until i keep driving the car. why is it like that?? i have a brand new compresser.

waitng for your kind reply.
thank you

377

Hi Zain, it may be low on freon or the condenser fans are not operating when the a/c is turned on . Jeff

378

thanks a lot for your kind and rapid reply.

bt i have confirmed both fans kick on when turning on a\c.
and i just filled freon 2 days back.

could it be bad condenser.??

a\c gets quite cold when on highway. stop on redlight and coldness goes away.

thanks again for your valuable suggestions.

waitng for your kind reply.

379

Hi Jeff
I have noticed green oil on my driveway from my 2001 Suburban — from my web searches it sounds like that it would likely be an AC leak — what is the best approach for diagnosing (I plan to inspect this weekend visually – but expect that it will be hard to pinpoint) And what is th elikely remedy?

Thanks

John

380

Hi John, first you must localize the leak to determine the next action ( hose fitting, seal, compressor ) . Then the system must be evacuated of freon, make the repair and recharge. Of course I have simplified the procedure but that is it in a nut shell. Jeff

381

Thanks

382

Jeff,

My 2000 Durango’s heating and cooling system is working fine, but there is brown, spongey material coming our of all the vents. I little accumulates on the dash when using the defroster. Should I be concerned or is my 12 year old truck just showing her age?

Thanks (great site!)

383

Hi Jeff,

I have a Nissan Pulsar 2001. The air conditioning has been mucking up for about 14 months now. In an effort to sort this problem, I had it serviced,flushed and re-charged, there are no leaks. Three (3) different auto electricians have looked at it and they can find no problems.

I had to have my idle motor replaced(it stopped working because coolant had got into the internal workings of it.) This also led to the computer board having to be repaired because it shorted out. I also had the alternator replaced and also later the brushes(?) repaired.

Depending on the outside air temperature, the cold air works intermittently. Currently not working at all, but tomorrow if it is a cool day, the cooling could work again. Also, if I am idling in traffic it stops working.

It has become progressively worse over this last summer and rarely works at all now….. Except when it does.

When working properly it is lovely and cool but this lasts for a max of 20 minutes and then it just blows hot again.
Originally I thought it may have been something to do with the interior controls on the dash, as cooling stopped sometimes when I made adjustments.(air temp, fast/slow etc.

Then it was suggested it could be the clutch mechanism not engaging properly. Something to do with the clutch plate needing to be shaved or skimmed or whatever, to ensure the ‘gap’ was correct.

Another suggestion was the ‘ignition switch’ could be the problem.

Then or course, there is the thermostat..this car has climate control.

I don’t know where to begin, to try and avoid unnecessary repairs.

Where should I begin now?

Keep up the great work.
Regards
Jen NSW Australia

384

Hi Jenny, there are a few things you can do to determine the problem. Are the cooling fans for the engine coming on when the A/C is turned on. Is the hot air coming out of the air vents outside air temp or hot. If hot then the blend door is to blame ( possible short in control head ) . A voltage test at the compressor when turned on ( at least 11.5 volts will tell if clutch is slipping ) A pressure test with gauges will tell whats happening inside the system( plugged condenser, restricted orifice valve, or bad expansion valve. ) Jeff

385

Hi Dennis, when the engine is cool check the engine coolant to see if it is the same color . Jeff

386

2000 mazda 626 starting its fined but when you drive it 10 minutes the car is died and then you have to wait atleast 15 – 20 minutes and the car is fined again to start….. I dont do anything yet.. Please need your help Jeff William.. Thank you!!!!

387

Hi Iglesias, It sounds like the ignition control module or the coil is heating up and then shutting down. I would start with those two first. Jeff

388

Hello Jeff, I have a question…
You may have already answered this, so forgive me for repeat question if so. But I drive a 2004 Neon. Whenever I start my car and left the defrost on, it makes this horrible squeal. If I turn it off, turn the defrost off, and then restart the car; no noise.
My dad thought it was the drive belt but that wasnt it. Do you have any idea what the noise is? or at least a direction to point him in?

389

Hi Aiysha, it does sound like the serpentine belt. Try starting the vehicle without the defroster and check to see if you still have the noise. If so then replace the belt. Jeff

390

Hi Jeff. I own a 2004 Nissan Xterra and my compressor is leaking freon. I charged it (before I knew it had a leak) because it was only blowing warm air. The freon charge lasted over night. When it was charged my compressor would cycle and my car was blowing wonderfully cold air. I took my car to the shop and the mechanic said I need a new compressor and an ac line (he did not specify which one). I am wondering do I need to get a second opinion or does this all sound legit? Can you do the work yourself or is it best to take something like this to a shop? I am not afraid of getting my hands dirty I just can’t take a punch of $1000+ to fix this ac.

thanks for your time!

391

Hi Kirby, I would say that if the compressor body or compressor front seal is leaking then yes replace the entire unit. As far as you doing it yourself I would say maybe if you have worked with R-134a systems before and have an evac pump. If not then no . Jeff

392

What happens if I don’t rotate the clutch of the A/C compressor as is mentioned in the instructions when installing it?

393

Hi Cindy, you could bend a valve in the compressor . Its called slugging the compressor. Jeff

394

Hi jeff,

Just came across your website and it is very informative and i believe it is assisting many people out there
I drive a Toyota surf 2003/ 4runner my only works when the car starts, then after driving for a while its stops working just got hot air. Again if car stops and starts AC works but stops shortly after. Hope you can shade some light on that.

Thanks

395

Hi Saabir, without knowing more info I would say to check your freon levels first. I Have a video on Youtube the shows you step by step how to do this. Just go to Ghosttownhunter in Youtube and look for A/C re charge video. Jeff

396

Great goods from you, man. I have understand your stuff previous to and you
are just extremely fantastic. I actually like what you’ve acquired here, really like what you’re stating and the way in which you say it.
You make it entertaining and you still care for to keep it smart.

I cant wait to read much more from you. This is actually a great web site.

397

Thanks for the great comments Janina. WE are working on a couple of things right now so you will see some more soon. Jeff

398

Hi, I have a nissan x-trail. I have changed the compressor, condensor, drier and valve, but the aircond is still not cold enough. The previous air cond was cooler but then it broke down.( the old air cond was blowing hot air sometime when idle)

Can you help me with this??

Thanks.

399

Hi Paul, sounds like you changed just about everything but the evaporator. Check the bled doors. Feel the two pipes going into the fire wall is one cold and the other cool or is on of them hot. Did you evacuate before recharging ( 30 minutes ) Jeff

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