hockeyhead019

Hey guys,

Just wanted to know what the best way to determine what the failure of the AC could be caused by. I know that the possibilities are generally a shot compressor or leaks in the line (which usually lead to no refrigerant which leads to shot compressor anyways lol)

So anyways whats the best way to figure out why the system failed and what to replace to get it back up and working?

You're gonna have to bear with me because I don't own the car I'm just curious from a pre-buying stance of how hard it'd be to diagnose the problem.

Also I was reading that the systems ran on an R-12 system... has anybody replaced it to run on a current fluid (I think it's R-134?)

Cheers

Jim

Jrboulder

Well what year cars is this?

hockeyhead019

Whoops sorry I guess I forgot to mention its an 87 944

944meister

There is a kit for these cars that converts it to r134, comes with the compressor and everything you need for about $500. The stock system will not run well with r134 from what I Understand.

xsboost90

stock system runs fine on 134a just need to change the compressor oil and drier.

MAGK944

Trust me it doesn't work as good as r-12 in FL, still cool but not as Ice-cold like before, I'd say 25% less effective as a guess. Will work fine if you don't live in a hot state.

I also had the old oil flushed out, changed all the seals to r-134a compatible seals and replaced the expansion valve when I converted.

Jrboulder

EPA 609 cert FTW

xsboost90

seals are compatable with 134a- thats a myth. It is good to replace whatever you can but not necessary- esp not the expansion valve if its still ok. EPA Universal cert.
i think one of the problems with the 134a conversion is that people weigh in the exact amount that is meant for the r12 charge. Not the same. You'll need alittle more 134a to get the right pressures. My 89 would freeze you out.

John_AZ

Rennlist sponsor 944online.com (Ians Euro Parts) sells a complete change over kit --R12 to R-134a --with new compressor, lines +++.

http://www.944online.com/cgi-bin/ASI...tecontrol-9442

DIY writeup:
http://www.texasblake.com/porsche/tech/ac.html

FYI typically the old compressor leaks at the shaft seal and should be rebuilt. Some members have had short success with just a full vacuum and install of R-134A. YMMV

A freon sniffer, or dye to check for leaks is a good idea.

John

hockeyhead019

Ok thanks guys so we have kinda a mixed opinion haha some say just change it out, others say it's fine with the r-134a lol well hopefully it's not a mechanical problem that needs to be replaced hopefully it's just the coolant isn't in there lol

joejoe

134 runs at higher pressure, and amount installed should be less than r12. To keep system stock I got the 609 cert and recovery unit about 7 years ago. Also bought 90lb r12,sniffer, dyes, guages, digital scale. What I need now is a gas analyser but they are expensive!

Remember a rumor awhile ago that a/c systems are changing again to a hard line type so 134 may be going the way of r12.

On the 928's I have heard good results, and mediocre with conversion to 134. Most that have good results seem to be in less hot environments. Where I live it can reach 110 and a friend (134) cannot understand why his car will not cool like mine do.

As John says sniffer or dye with black light is very good idea. Sniffer can locate most leaks (you need to reach places with probe) and dye will show all leaks. If you replace anything in system do yourself a favor and replace all 'O' rings with the newer style. Sorry for rambling , kinda fighting flu still.

hockeyhead019

Thanks joejoe, no worries about the rambling, I'm just as bad usually haha

Ok well it really isn't a must, nothing wrong with driving with the windows down since I leave for work early before the sun is up and well the ride home would be a little hot but whatever it definitely isn't a deal breaker in my books.