R12 or R134 a/c???

[Mat 71]

Is there a way to visually tell whether my car has been converted? It worked a few times this past summer and then all of a sudden no cold air. I can see movement through the site glass on the compressor, which I assume is a good thing.

Where do I start to diagnos the problem? I would rather try and figure this one out know while the snow is still flying here.

Thanks in advance for any help/suggestions.

M.

[Danglerb]

When mine was converted to 134 the kit included stickers and new fittings, but I can't find any good picts of the various connector types. Any auto AC pro should know what kind you have.

[911blex]

The high and low pressure a/c ports on your car will likely have R134a adapter fittings screwed onto the ports if it has been converted to R134a. The ends of these fittings can best be described as a "quick release fitting" like that on an air compressor hose. If your high and low side ports have threads on them, your system is likely still R12. However, be sure to look at both ports as my car had one R12 port and one R134a adapter on it when I bought it (the conversion wasn't finished).

In my opinion, if your system is R12....keep it that way as R12 will blow colder and you will likely have to replace fewer parts to get your a/c working again than if you convert to R134. R12 can be frequently purchase on ebay or at car shows/swap meets for reasonable prices so don't let anyone convince you it is prohibitively expensive or can't be found.

Also, I read in the latest Panorama that that R134 will be phased out in all European production cars by 2017 because R134a is far more damaging to the ozone layer than R12. This is yet another reason not to convert to R134a.

I recently finished an R134a conversion that the previous owner of my 88' S4 started and would be happy to answer any questions you have.

[icemang17]

R12 was standard on all pre 1993 928's.....R12 does have more cooling capacity than R134...the bummer is it is getting pricey...however a properly converted R134 system will be plenty cool.....with that said my R12 system gets Wicked cold.......I can get 50-60F under ambient temps....I've seen as low as 15.5F coming out the main vent!

[dprantl]

Originally Posted by 911blex

Also, I read in the latest Panorama that that R134 will be phased out in all European production cars by 2017 because R134a is far more damaging to the ozone layer than R12. This is yet another reason not to convert to R134a.

That is incorrect. R134a has negligible effect on the ozone layer. It has, however, been found to contribute to global warming. While ozone depletion is fact, global warming is a loose hypothesis at best.

http://en.wikipedia.org/wiki/R-134a
http://eur-lex.europa.eu/LexUriServ/site/en/oj/2006/l_161/l_16120060614en00120018.pdf

Btw iceman, your anti-freeze A/C switch must not be working if your vent temps are below 32F.

Dan
'86 928S 5-spd w/LSD

[icemang17]

Originally Posted by dprantl

That is incorrect. R134a has negligible effect on the ozone layer. It has, however, been found to contribute to global warming. While ozone depletion is fact, global warming is a loose hypothesis at best.

http://en.wikipedia.org/wiki/R-134a
http://eur-lex.europa.eu/LexUriServ/site/en/oj/2006/l_161/l_16120060614en00120018.pdf

Btw iceman, your anti-freeze A/C switch must not be working if your vent temps are below 32F.

Dan
'86 928S 5-spd w/LSD

Dan
I was thinking that too.....but it looks fine...I checked it when I cleaned the evaporator......I know it works, since it will cut off the a/c for a period of time when I've been running it full blast for a while.....but it hasn't done it since I fixed the recirc flap?