[gaca2go]

I've got a 1970 GTO (very seldomly driven) with all the original AC equipment underhood that has worked fine for many years. The system has now completely lost its ability to keep me cool in the cockpit and simply blows warm air. I suspect the R-12 Freon (last topped-off about 10 years ago) has all leaked out. Obviously, time to update/rebuild, etc.

For the last several years, I heard that the R134 retrofit was the preferred update for a situation like mine. But nowadays, I keep hearing that there are even newer formulas or solutions coming along to consider. While I'd prefer to keep everything underhood original, I know that may not be practical.

So, what do you experts out there suggest for my current-day AC system update? Is a R134 system still the way to go, or ???

[Goatracer1]

First of all find your leak. If you fix your leak (most likely the front seal on the compressor) there is no reason not to recharge with R12. That's what the system was designed for. If you really want to change to R134A then you must still find the leak especially since R134A will find smaller places to leak. Remove the compressor, empty the oil and refill with PAG oil. Replace the drier and hoses, using the new barrier hoses. And remove as much of the old oil from the system as posible. Using the adapters recharge system. It may not be as cold as before.

[gaca2go]

Since posting this question, I have found a reasonably-priced ($35 for a 16-oz can) source for R-12, and I think it makes best sense to stick with this original chemistry. Does anyone know how much Freon I'll need to purchase for my application? Again... I've got a 1970 GTO with 400-4bbl and THM 400 transmission.

[Goatracer1]

It should say on your compressor's label. If not 3 lbs was common.

[george kujanski]

Probably replace the hoses regardless.

George

[Schurkey]

I pull the system apart to install ALL new O-rings, and an accumulator or receiver/dryer (new dessicant bag). TEST for leakage at the compressor seal. Barrier hoses are preferred. I keep hearing that old hose has absorbed so much A/C oil that R134 doesn't seep through it, even though it might seep through new hose of the same kind. Vacuum the system overnight.

Me? I bought cases of "pounder" (actually 12--14 ounces) cans of R12. I'll use R12 until I can't get any more.

Don't forget to dig all the leaves and pine-needles out of the evaporator and heater core box.

[android 211]

I prowled local Craigslist and picked up a half dozen 12oz cans of R12 and a 15lb. tank. The cans were about $20 or $25 each and the tank was $200. Theres lots of it still out there.

[Rob B]

If I'm not mistaken, The Mexican made R-12 is partially propane. I'd check into it before using.