The A/C on my 88 automatic isn't blowing very cold air this year. I had the coolant conversion (to r134) done a couple of years ago and the A/C got pretty cold. Last year I had to add more coolant and it got cold, but not as cold as the year before. This year, I tried to add another can of coolant and it would not go in making me think that the coolant level is not the problem.

I can feel and hear the compressor engage when I turn the A/C on, and it cools down a little. Just not as much as it had in the past. Do I have a problem somewhere else in the A/C system? What else could be wrong if it's not the compressor or the coolant level? Any ideas....

Thanks...

 

might need a complete service, to replace the coolant...not real familar with the r134 conversions myself, but that would be the first thing I could think of...

 

How does coolant pressure look? Have you checked the site glass at all? It could be your bleeding off pressure from a leak....and I lean more towards that because you're adding more coolant. And keep in mind you don't have to loose a lot in order for the system to stop blowing cold air. I suggest getting a pressure test done.

S

 

Mark, You definatly have a leak, that's what caused you to convert to 134a in the first place. Someone should have told you that 134a has smaller molicules than r-12, and if you had a leak that was not repaired when it was converted, the leak is going to be worse with 134a. Get the system checked by someone who's not looking for "repeat buisiness" . Earl

 

on some conversions, when they replace the dryer, some times they dont have little windows.

 

Well it's still worth checking.....no way to tell if his has it or not.

S

 

If its a closed system, where do you suppose the refrigerant went????? Earl

 

lol 10chars

 

Is that your final answer?????

 

The problem with my A/C is pretty much the same as what has been mentioned above except for one thing. MY AC actually blows HOT air into my car when I engage it. Not only that, but hot air enters the drivers compartment on a regular basis when nothing is engaged, but the car is moving and warmed up. I am thinking that one of the valves in the system is letting in hot air from the engine compartment through to the ducts that let air into the drivers compartment, Can anyone help me please???

 

Welcome to the forum!!!
Roger, You don't tell us what year your car is, but It sounds like the actuator, either cable or vaccum operated, is not working, and the air door to outside air is always opened, or the air blend door is at the heat setting.
Have you tried driving with the A/C set to re-circulate? do you still get air flow with the fan off?
Don't forget the heater matrix is always hot, and the doors are the determining factor as to the source of the air.
HTH, IE, hope that helps, Earl

 

To really do the R134a conversion correctly, you must replace all the hoses and seals in the system AND the compressor. R12 runs at lower pressures compared to R134a; the R134a will put more stress on the compressor seals and such. I would suggest that you use a 4-Seasons reman unit (www.4s.com), as they are well built. R134a is OK in cooling, but I was told by a person who know a A/C expert that R12 is BETTER for the environment than R134a, and that the MACS and others wanted to make the switch because R134a does not transmit oil as well as R12 and as such, the compressor will wear out sooner running R134a. Has anyone else heard this?

Still, even if the oil thing is true, R134a is the one real (non-blend) refrigerant for a car. For now, anyone can buy as much as they need and can find anyone to service it. That, and like you can find pure r12 these days, and even if you can it will cost you real bucks to get it. Ah, how we long for the good old days of long lasting R12 systems (notice that you can find Nissan cars from even the 1970's/80's with the original R12 system that has never been serviced and STILL works).

 

Anyone seen the data that talks about R400 (isobutene) for car use? I have seen some pages from Australia that talk about it being legal in certian places there.

 

Oh, sorry. My car is an 86 maxima GXE automatic with the automatic climate control

 

Why do you think the EPA banned R-12????
R-134 has one less florine molicule in it if my old memory serves me right, and the florine is the ozone killer at high altitudes.
Yes R134A runs at higher pressure, but it also has smaller molicules that will leak out of a hole R12 wont. And the reason for changing the seals, and o-rings is the R12 o-rings and seals are not compatable with the esther oil used with R134A. You cannot leagaly purchase R12 in the USA today, so you don't have much choise other than retrofit with R134A.
I was a refrigeration tech for over 20 years, and went thru all the training on the change over, and it was a pain at the time, and I still have some doubts about the reasons.
If you think I'm wrong, let me know, Earl
P.S. My '84 maxima wagon is still R12, and I re-charged it this spring with "Freeze 12" purchased at an independant auto parts store, and it'll freeze you out on a 110 degree day here in tucson, vent temps in the 40's!!!! :attention

 

Yes...check the vaccum lines on the firewall...after a oil change at the local Wal-mart....in removing the oil filter from the top...they pulled off a vaccum line and my air-cond was blowing hot air from the vent....replaced it..problem gone.....good luck..

 

Where on the firewall is this vacuum line located?