The Gooch

How difficult is this to do and how pricey? Also, I understand that you have to replace compressor, dryer, accumulator (?), anything else?
I'm thinking of trying this myself.

War Machine

I was told that I must take it to a shop that can evacuate all the R-12 and from there all you need to do is change the fittings so you can hook up the R134a. No major parts replacements. I hope someone can correct me if I'm wrong b/c my wife said she would kill me if I didn't get the A/C recharged and I can't afford all new pieces.

Ozman

I would like to know what year they switched from R12 to R134a? I have a 93 and need to know what I have.

VetteNoob

Im sure there will be someone here that will argue with me about how this should be done. This is just what I personally did when converting my AC system. Had a shop evac the system. I replaced the compressor (mine was dead), dryer/accumulator, o-rings, shrader valves, and orifice tube. When you have the AC hoses off, try to clean them as much as possible to get rid of the old oils. Fill your system with PAG oil per your service manual requirements. Pull a vacuum on the system for 30-60 minutes. I did mine like this and it has been working fine for the last month or so. While you have everything apart, take a look at your condensor to see if that needs replacement too. I should have replaced mine because it was all beat up and airflow to my radiator is pretty restricted because of it. If you are unsure, you should take it to a shop and have all this done.


OZMAN: I believe 1994 was the first year the federal government mandated the R134a system to be used on ALL new vehicles in the US. However some manufacturers started using R134a prior to 1994. Im not certain if your 1993 is 134a or not though. If I were a betting man, Id say you have a R12 system.


[Modified by VetteNoob, 8:56 AM 7/23/2002]

xzvs

If you ask 4 a/c mechanics about this you will probably get 4 very different opinions on the subject. I have been doing a/c work for 15-16 years on cars and I do what works for my customers and myself. It is best to do the retrofit when doing a compressor change. Other than that I have had a lot of success simply adding some 150 pag (gm's--bout 6-8oz) and charging the 134 to 85% of the reccomended 12 charge. If the system has been wide open (hole in hose etc) you need to do the accumulator too. Any visual leaks should be fixed as 134 tends to escape easier than 12 (smaller molecule). If you have to change a hose it must be replaced with nylon barrier type hose for the 134. A non barrier hose used for a few years on a 12 system will be ok with 134 as it over time will build a barrier of its own. If at all possible you need to evacuate the system with an a/c vacuum pump for at least 30 mins. If the system still held pressure tho you can get away with simply recovering the remaining 12. You do not want to let your old 12 into the atmosphere on purpose. A lot of really creepy people who still live with their mothers, have apparantly figured out that r-12 will be the death of us all. I still have not figured out how they got up into the ozone layer and saw the 12 rambo-ing the ozone. But, apparantly the govt believes them and will sock you with a huge fine, and avoiding a huge fine is pretty much always a good thing.

The Gooch

Thanks for the advice everyone. Your right about different responses from different people. My A4 R-12 unit has a leak on the clutch shaft seal. I decided to go ahead and replace the entire compressor because this unit is very old and I suspect getting tired. I'm going to replace the accumulator also. I was told to take the system apart, clean it with a flush with compressed air. Put the oil for R134a into the condensor, accumulator, and compressor. Then charge the system.
The R-12 that I had in my system has leaked out, so I might as well convert it over.
Oh, the replacement compressor is $394 :eek: Just alittle steep!!

VetteNoob

WOAH on that compressor! I bought a R4 compressor (Four Seasons Reman) from AutoZone with a 1 year warranty for $99 including the clutch. Check http://www.autozone.com for your particular car, but I think it is only like $96+$10 core charge.


[Modified by VetteNoob, 10:58 AM 7/23/2002]

Jim D

The 93 is R12,they changed to 134 in 94. Ijust charged my 93 ,I bought a 40 lb drum before it was outlawed, but I think it sells for about 90 bucks a pound , and you have to be licensed to buy it. You can take the test on line if you choose ,just do a thread search. Good luck Jim

GiDvEtTe84

You will need to evac the system, change the orfice, o-rings, receiver drier, all rubber (hoses) because R12 hoses arent compatible with 134a and will leak after some time.

MrNuke

http://www.autorefrigerants.com has a quick-change kit that is supposed to be VERY easy to install/charge... I got good response to a question from them, but have not had the time to order or change mine over yet.

drive it

Check the tech tips and read up at the link to the .gov site.

Pete Pulos

Try this $35 solution. I did it last August and still working fine. http://www.id-usa.com/faq2.htm