What is involved in converting an older non-working AC unit that uses the R12 stuff to the new R134? The non working unit just needs a new receiver/drier. Anyone done this conversion? Thanks Jim
Depends. I've changed them over by just flushing the system with rubbing alcohol, installing a new drier, vacuum down the system, put in new compatible oil and R134 and they worked fine. Others I've had to go through and change the O rings out to the green ones. Your results may vary....
The simplest answer is changing all the seals, oil, and dryer, then recharging w/134. For best long term results, making sure the compressor, condenser, and other components are up to the new challenge is advised. While apart, you might want to put in one of the hi/low pressure cut-off switches.
The "by the book" correct way also involves changing from flare fittings to O ring ones, and using barrier hose, instead of the older versions. The molecules are smaller and can get past the older methods of containment. R-134 doesn't cool as well, but changing to la larger condenser is supposed to help.
Thanks a lot guys I'm sure I can't do this myself, but wanted to have the info when I find someone to do it. Thanks again Jim
Or just fix the leaks and put some R12 in it. It's not hard to find it, at least around here... I know of a few shops that have 30# cans waiting for someone to want to buy some. Maybe you could even negotiate a good price if you try, let them know that you're one of the very few remaining customers who wants it.
In the past I've done it by removing the R12, pumping the system down. replacing the servicing ports with the larger 134 type and reservicing the system with R134. No problems system worked just fine.
The safety pressure switch is a good idea, but then you have to modify the hose. I would just try the flush, vacuum, refill with R-134a and see. For sure use gages to charge, and if you can add a larger condenser it will help to work better. The reason is R-134a needs more cooling for optimum performance, but the older condenser will still make cool air, just not as cold as could be. Or use Squirrel's advice and just refill with R-12, once you locate the leaks. Since the condenser is sized and works best with R-12, that will give you cool air.
Good question I have been wondering the same thing about getting the A.C. going on the olds wagon.The compressor still kicks on when I turn it to A.C. Bruce.
If anyone remembers back when 134a first came out in autos, it*****ed! Felt good cruising down the road but as soon as you came to a stoplight-warm air [emoji35]. There wasn't enough condenser back then and you starved the evap at a stand still. Definitely get a bigger condenser if you're going that route. I would definitely just fix your leaks and recharge with 12. Much better refrigerant for auto use. Better for everything it USED to be in! Stupid treehuggers.
I really want to thank all of you for the respomses. I only thought about the R134 because I had heard that the R12 is terribly expensive and maybe not available. Now, I'm gonna check. Thanks again Jim
Katuna: electric fan helps a lot! I think that's one of the main reasons the manufactures got away from just a mechanical fan (at least for full size cars and trucks. Transverse kinda speaks for itself y no mechanical)
Yes, definitely. Much more efficient than a mech. fan and keeps working at a stop. My thought is, since you can still get 12 (and the price has come down significantly), stay with 12. That's what your system is designed for. It's a much better refrigerant. It'll condense in a snow storm.
Again, everyone, thanks for all the suggestions. This is an old Mopar that has the original factory air and, if possible, I'd like to keep it. I'm not against making changes, cuz I like cool air at my advanced age. Thanks so much Jim
Cans of R12 pop up on eBay all the time. Pick your price, although they are not going to be $10 a can like R134A.
If you can't find R12, use R414B. It's a direct replacement for R12. It cools better and is compatible with all the hoses, seals, oil, etc. It can even mix with R12. The only difference is you have to add it as a liquid and you only use 80%. In other words, if your car calls for 10 ounces, use 8 ounces. I've used it for years in cars snd refrigerators.
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