Vifa

Since my R 12 a/c doesn't work anymore, I was told to rebuilt it before it could work again. BUT a guy I know have told me he has something called RS 24 which is mixable with R 12, and then it would not be necessary to rebuilt it. Does anyone have any experience with this? I don't know if this would be a good idea.

springer3

Issue has already been beaten to death, and there is no consensus. Do a search. www.epa.gov has a listing of approved "drop in" replacements and some pretty authoritative information on the subject. Freeze-12 seems to be the most poplular, but "drop-in" replacements for R-12 are mixes of refrigerants with molecules bigger and smaller than the R-12 molecule. They work as long as the system does not leak. If the system leaks even a little, the smaller molecules leak out faster, and the mix ratio gets off. Thermodynamic properties and compressor life suffer when the mix gets off.

Note that every 964 left the factory R-134a ready, even those charged with R-12. The service valves need to be changed, and if mineral-based refrigeration oil was charged into the system, it will need to be flushed out (not a big deal). If your system leaks, you need to fix it. If it does not leak, simply flush, install new oil, and charge with easily-available, inexpensive, and effective R-134a. There are nay-sayers, but every car maker in the world uses R-134a on non-EV cars and trucks. They are not all idiots.

Gelignite

I have been running mine with RS24 for two years now and it is still blowing cold. I have no clue if it is also damaging my compressor but the mobile air-con specialist who did it was confident it would be OK. He also rebuilds compressors so if it does fail I am sure I can strik a deal with him. I guess an annual service wouldn't be a bad idea though.

Geoffrey

Are you sure about that? The hoses on a 93 and 94 have a different part number. With that said, I put the 134a update kit on my compressor, replaced the dryer with a new one and charged it with 134a. It has been ice cold with no issues.

jjbunn

Excellent summary. I've been using Freeze12 in mine for a couple of years, and am happy. My system has a slow leak, and so I find I need to add a can of Freeze12 before the Summer months start, a 15 minute job. I could have converted to R134A, but didn't see it made any economic sense.

N51

Four years ago, I drove my RSA across the desert in 110+ degree heat. Never moved the fan above 2. Now, it's a little weak. I'll convert to R-134, same as my ag equipment. These cars have an excellent AC, if properly maintained.

Shucks, these cars are perfect, if perfectly maintained.

springer3

Only because the service valves are different. I have forgotten the date the treaty was signed, but The R-12 production ban was effective on Jan 1, 1990. Through 1992 Porsche used up inventory of R-12, and started using R134a in 1993. Barrier hoses are OE on all 964s including the 1989 first year.

velocitylover

Thank you for this info.Will help a lot when my R-12 stops working

dutchcrunch

just flush and reservice with 134a if system passes the leak check...


what about hte reciever/dryer on my 1990 c2 i have a sightglass....... i thought you had to change it out?????



my r12 is still going strong



you can still buy small cans of r -12 on ebay.

stevepaa

Also the lines to and from the dryer were changed as the dryer was changed. New dryer (93 on) is cheaper than old (up to 92).