[flash]

there is an oil in there to keep things moving

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[968rz]

Sounds then like the valve leaked (or cracked). And really a completely empty A/C system should only have about a once of oil in it, any more can cause problems.

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[flash]

120cc +/- 20cc - that's about 4 ounces

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[Kim]

Well there is now a new twist. I don't know what the fluid was that was under the car - I presumed it to A/C oil since the A/C had stopped working - but I removed the fuse box cover tonight to be sure that the A/C fuse wasn't blown, discovered that there was an A/C compressor relay that was loose, probably since all the work was done in that area. Pushed it back in and - presto - I had A/C. So the oil could have been blow off from the newly filled coolant reservoir (it looked clear but I suppose it could have been pink, that would have been the place to find it), something else (not sure what, nothing else on that side of the car except the A/C reservoir) or some other peckerhead with a junko truck was in my driveway visiting kids, leaked oil, and I simply didn't see it when I parked. Who knows. WHO EVEN CARES? Life's been good to me so far.

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[968rz]

Nice, we all like the easy fix.

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[p65356sc]

I went to my local AC fix em up shop and asked about the R12. In CT you can't buy it. He said the replacement for R12 is PROPANE based. Driving a bomb anyone?

Ross

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[banditsc]

I just went with ES-12A in my newly aquired car. It is CFC based, but has a higher ignition point the R134a, so it catching fire shouldn't be a concern. This product is also environmentally friendly the EPA deemed it as not needing to be regulated and Greenpeace is endorsing it. They even put in a pine scent to detect leaks to go along withere enviromental theme. The stuff is suppose to cool better then R12 and R134A and cause less of a load on the compressor. People are actually swapping R134a for this stuff. Another nice point to this stuff is the molecules are larger then R12 or R134a so it's less likely to leak. I'm actually thinking of swapping it in my 968 which has R134a, in hopes it actually does reduce the load on the compressor. I also learned from researching R12 substitutes that one of the long term health issues with R134A is Testicular Cancer, I sure hope it hasn't been leaking into the cabin..



Tech Details here. http://autorefrigerants.com/Envirotechnical.htm

I got mine from here, http://autorefrigerants.com/co00033.htm

The Manufacturer is here, http://www.es-refrigerants.com/

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[apex]

(aside: wow! been away from the forums for a while - lots of traffic and many interesting posts.)



I just finished a complete upgrade to my 92's AC - new condenser, compressor, high side hoses, dryer, expansion valve, and retrofit from r12 to r134a. And I must say it blows very cold - even when the cars been in the sun for a while. It was by no means a quick job - but not that hard technically. I did all the heavy lifting myself and took the vehicle to my friendly neighborhood ac shop for the technical steps.



I've got photos and when I get some time I'll post here with a write-up.



ES12a sounds interesting - and uh, SUDDEN DEATH WITHOUT WARNING is a rather disturbing, "short term health risk" of 134a - what in the world is that all about? <img src="/forum/images/smilies/968/blink.gif" class="smilie" alt="" />

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[968Z]

Just out of curiousity, the conversion kit I bought for $40 bucks works great. No leaks-Blows cold. Why would anyone spend $1000+ to switch out the various components. Am I missing something? I spoke to the A/C mechanic at my local repair shop, and he said he's done both methods - both work equally the same in his opinion. Even if you plan to switch everything, he tells people to try the R134A recharge kit first. What is the catch?

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[apex]

[quote name='968Z' post='56978' date='Jul 30 2008, 07:46 PM']Just out of curiousity, the conversion kit I bought for $40 bucks works great. No leaks-Blows cold. Why would anyone spend $1000+ to switch out the various components.[/quote]



In my case - the original stock compressor seized - replacing that was the lion's share of the cost.



When a compressor goes the entire system can get contaminated with grit from the failed compressor. To be sure the new compressor is not ruined by dirt in the system, a nitrogen flush is called for - starting with the evaporator coil and through every hose and tube downstream.



The new condensor was a splurge on a more efficient unit than stock - designed for r134a since I was making the switch. The expansion valve was less than $50 - but a true and royal PITA to access. Opinions differ as to whether it really needed to be switched out - but I took the safe route and did just that.



In my research I found anecdotal evidence of both approaches working - (lo-dollar vs hi-dollar) - but an equal number of warning and caveats about the possiblity of introducing air or moisture into the system. Also I believe it's important to at least replace the hi-pressure side compressor hose with barrier hose as over time the r134a will leak through the old hose designed for R12.



Could be worse: we could be driving a 911 - 40 feet of AC hose to deal with on that car!

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[xrad]

apex: what compressor type/# etc...

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[apex]

Everything came from Griffiths - you'll find them on the web. They specialize in porsche AC and steering. I went with his "kit" which includes everything you need to make the switch from 12 to 134, plus the new big stuff: the two c's: compressor/condensor. Charlie recommends that after his hardware is installed you take the car to a pro to pull vacuum, test, and fill. Good tech support, too. I needed a little hand-holding at first. <img src="/forum/images/smilies/968/happy.gif" class="smilie" alt="" />

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[earossi]

Before I would spend $1200 for an R12 to R134 conversion, I would dump the R12 and refill the system with R134, without changing out any hardware and evaluate the perforrmance of the system. I did this with my 95 Mercedes and it worked just fine. Probably not quite as cold as R12, but it worked very well in the 90 - 95 degree heat we often get in a Chicago summer.



Before making the change in gas, I did some research and found conflicting information out there. There were those that said that the entire system had to be dumped, including the oil. Others said that was not true. So, what I did was to re-evacuate the system to remove all the R12 and then recharged with R134. Added some Ester oil that is compatible with both R12 and R134....and then drove the car for almost 2 years without any complaints.



Bottom line......before spending any money, try just changing out the gas. My belief is that the only negative consequence from this may be slightly poorer cooling. You will NOT damage any hardware with this little experiment.



Just my two cents.

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[apex]

I think you're basically right - but a new receiver/dryer would help - and they're cheap and easy to install.

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[flash]

it is my understanding that the seals are not compatible - there was a thread about this a long time ago that talked about it - i'll see if i can dig it up



i think enviro-safe was compatible with both systems though, and made it cooler than either

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[banditsc]

Correct, the Envrio gas I posted above is compatible with both systems.



The main differences with the two system are the oil and the hoses. The oil that R12 uses is not compatible with R134A, so you really need to pull a full vac on the system and replace with the proper oil. Failure to do this will result in the compressor eventually failing, you also can not mix the oils. The other issue are the rubber hoses, the R134A system uses barrier hoses, putting R134A into non barrier hoses will eventually cause the gas to leak out thru the hoses. The o-rings should be compatible with the R134A, but given the age and heat in the engine bay they are most likely getting old and hard, so replacing them would assure a good sealed system.



So yes, a R134A kit will work and blow cold air in a R12 system (though not as cold), but will eventually leak out and can cause compressor failure if you don't change the oil. Or the other solution is ES-12A gas which is compatible with both systems, hoses and oils and blows as cold or possibly colder. It's price is also on par for R134A kits.



Of course if your doing any of this changing out the drier should be done if your making a change or the system has gone dry. Also if the system has gone dry pulling a vac on the system is recommended.

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[flash]

ah - ok - that seems to be what i remembered - then, as with any other rubber product, the hoses and seals need to be changed, as any oil will embed in the rubber, and result in leaks, failures, etc when you change the oil type



yet another reason to use enviro-safe - seems like a no brainer to me

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[apex]

green o-rings for 134a - to do it right replace all the black ones.



ha! but that means you need to access the expansion valve which is under the hood, under the shroud, under the blower cover, and wrapped up tight under sticky black dum-dum tape.



Here's a link y'all might find useful. No affiliation:



Griffiths a/c info page



Oh and here's the stuff I installed re an earlier question upthread:



Griffiths page - where I got my stuff

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[Gotter]

OK, so my A/C has gone caput. And when I was in AZ, I really didn't mind much, b/c I had a three minute drive to work and it rains like 4 days a year there, so windows down was ok.



But now that I am in Georgiabama, the humidity has gone up quite a bit, and the commute has grown to 45 minutes. OK in the AM, but at 4PM, it's brutal.



First off, I need to check with my old mechanic, b/c he supposedly replaced the Schraeder (?) valve in April, but it was never really ice-cold... but not working at all now... I need to see if he will pay for the re-repair. Which brings me to my question:



The nearest 968 guys are probably AutoAtlanta, about 90 minutes from me. So for an A/C job do I need Porsche expertise, or should a local reputable import place or general A/C 'specialist' know enough to do well enough? I don't know how 'specialized' our A/C units are. There's not a Porsche dealer here... and I don't know if I'd trust them anyways. Better yet, any recommendations for the job? I'd love to avoid two 3-4 round trips for this repair (one for diagnosis one for repair), but if I have to, I have to.



Thanks in advance, guys!

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[apex]

[quote name='J.C.' post='57329' date='Aug 4 2008, 07:05 PM']...for an A/C job do I need Porsche expertise, or should a local reputable import place or general A/C 'specialist' know enough to do well enough?[/quote]



Based on my recent experience, a skilled perfectionist local AC dude will do you fine. Depends what the problem is with your system - you need to find out what's wrong first. Having worked on 944/968 in the past will certainly help but AC is AC.

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