The only thing you can really do with a compressor off the car is to spin the clutch to make sure it's not seized. I suppose you could also pressure test from the ports, but that wouldn't tell you if it would leak while actually running. There could be many things wrong with it even though the clutch spins...

Dan
'91 928GT S/C

 

Are you up in Norcal yet? If so, hook up with Bill Ball. He has all the proper R-12 equipment at his house. We often have A/C repair sessions at his place...might need another one with hot weather upon us.

Rich

 

So my self- 'rebuilt' 10PA20C for my '90 only lasted about 3 weeks before leaking all the freon out past the front seal, despite the system holding a solid 30 mm Hg vacuum overnight after evacuating for 6 hours or so. I guess that being able to hold 30 in Hg (1 bar) vacuum is not as big a stress on a compressor seal compared to the ~250 psi (15-18 bar) that the high side sees when the compressor is operating.

I threw in the towel and picked up a professionally rebuilt 10PA20C from 928intl and will install it soon. I was only out an additional $60 or so having tried to rebuild it (gasket set, shaft seal, and shaft seal tool), so the only real loss is my time, no biggie. At least I learned (once again) that I don't know what I'm doing!

The other issue of course is that the compressor that I rebuilt was not the original compressor, it was installed in 1998. It was at a dealer (Newport Auto Center) and cost $630 then (928-126-11-X). If it was a brand new unit, then it's now 10 years old. If it was a rebuilt at that time, then who knows how old it is? Bottom line, perhaps it's false economy to try to DIY a 10+ year old compressor? Perhaps the reason a rebuilt is $500 that a pro actually can tell if internal bits need replacing, whereas I just slapped some seals and o-rings onto it? Or am I engaging in wishful thinking, and the 'pros' just clean it up, slap a seal and gasket kit onto it, and bill 5 Benjamins?

Jim? Roger? DR? Thoughts?

 

Andy,

I have a working compressor with a failed clutch in my car and a spare used compressor and clutch sitting in a box in my garage. I have been meaning to try to get the clutch swapped out just haven't had time. If you are not in a hurry and I can get it done in the next week or two you are welcome to the spare compressor that I have. I have no idea as to the condition but I was told that it was a working pull.

Michael

 

I sell the Porsche rebuild factory compressor for $475 with a $200 core charge.

 

I have never had a 10PA20C apart before, but I have rebuilt Sandens for my SAABs and a 6E171 for my former 928 and can tell you that rebuilding them yourself can work. All the shaft seals I have replaced are still holding (that's years). There are some tricks for the compressors with a lip-seal. You must use the correct installation tool, or you will bugger up the shaft seal and it will fail prematurely. You should also apply compressor oil liberally to the seal when installing it to make sure it doesn't get dry before first operation. I think $500 for a rebuilt compressor is robbery, I bet it takes them 30 minutes and $20 per compressor in their cost for parts. Oh, and I routinely hear of "professionally" rebuilt compressors taking a dump as well.

Dan
'91 928GT S/C