I had my a/c compressor replaced a couple of months ago but it wasn't pushing air out so I put it in the shop and they replaced the orifice tube, o rings and I beleive the dryer for $168. Now just two weeks later it stopped working so I took it back. They said a switch went bad and replaced that, the orifice tube (which had gotten clogged again), the o rings and charged me $155.02. I just picked it up Tuesday and the a/c worked great, on Weds it went out again. I had my son take it back to the shop today and just as he got there it started working again. He brought it home and it quit, he took it back and it worked again, he brought it home and it quit. What the heck is going on here????? Is my car possessed?

Alright, first off by the A/C doesn't work, do you mean that it doesn't blow anything? Blows ambient temp air, blows kinda cold air, etc.. gotta get into detail about what you mean by the A/C not working.

2nd, did the shop retrofit a new evaporator and fill it up with R-134, or did they keep all the stock A/C Components and use R-12?


-justin

It blows not cool air. The shop put freon in it (per the reciept) I don't know if it was R12 or R134. I haven't spoken with them. My son has been handling this for me.

Try to figure out if they put in a new evaporator and converted it to R-134a, or left it alone and used R-12. Or if they just put R-134a in the factory setup.


-justin

I got the info on the car. It'* going back into the shop on Monday. They are going to replace the accumulator and re-re-replace the orifice tube (this is 3rd one), clean the system and recharge it with R134A and charge me another $150. This thing better shoot ice fricken cubes after this!!!

Alright, that'* what I thought. Now, this is just an inference. But my experience with converting an R-12 car with R-134a, the system just really sucks. There is just some incompatability with 134 and 12, that just mixes together, and makes problems. The car I worked on, it worked one day, fucked up the next, recharged, worked really shitty [barely cool], then never worked again. The A/C in the car was given up on, because it pretty much all needed to be replaced. I don't want to be negative or anything, but that'* my experience with converting 12 and 134a. If you can, TRY, try REAL hard [hit on the guy at the shop if you have to], to get them to put 12 in. It'* super hard to get, but certified shops [you better be dealing with one of 'em] can get 12. Ask to speak to a manager if you must, I know they can get it. if not find one which can.


-justin

Most shops will not put in R-12 anymore. It is no longer produced, and is EXTREMELY expensive. I work at a shop, and a 30 LB container is roughly $1400 dollars. 30 lbs of R-134a? Bout $120. Besides that fact, you need special permits not just to operate A/C equipment, but also to handle R-12. Because of this, most shops will retrofit the R-12 systems to R-134a systems. Now as per my own experiences, R-134a does not cool as well as R-12, i'll admit that readily. BUT, if the conversion is done correctly, and by that i mean the old R-12 is taken out of the system, the system is vacuum checked for leakes for at least a half an hour, and a new charge of R-134a ester oil and freon is put in, it can work superb. This all relies of the condition of the original parts, of course. If your old R-12 compressor is no good, well it'* not gonna work very well with the new stuff either. Also, just as a side note, these cars are notorious for clogging orfice tubes. I don't know why, but GM made them easy to change, so they probably knew it was going to happen (just like the alternators going out lol).

Alec knows a little bit more about A/C than I do.

I knew it was more expensive, but I didn't know that expensive. Don't we only need like 3-4lbs of it refridgerant?

To convert to 134, I know you need a new evaporator, for like you said, it does not cool as well as 12. But 12 is bad for the enviornment, ooooooo..


-justin

It had previously been converted and worked fine all last year but I let one of my sons friends dad work on it and he screwed it all up. He is a heating/ac guy for homes and he apparently didn't know the difference.

Many people fail to note that you do not use as much R 134A as R-12, too much and it won't cool properly. I have all of our cars (except the '70) converted and at 94F like today, I cannot leave it on MAX COOL for long.

I have tried variable oriface tubes but they work best in over 100F/dry climates and see very little difference in Florida. I would suggest a GM "white" (.072") orifice tube and replace the tube and drier any time the system is opened for moderate temp/high humidity like around here.

Has anyone really experimented with different orifice sizes and VOVs when converting to R-134A ?