mdkelly1

I also went with Griffith's R134a conversion kit & new compressor about ten years ago and it's worked fine since. Found them great to deal with as well.

Pfc. Parts

Done, and thanks. I now regret spending $100 on a virtually useless vacuum test I could have performed in my own shop had I known I could buy the entire vacuum pump and manifold for $150. On top of that I had to buy my wife fish and chips and take her and the dogs to the beach while I waited for the test to finish. To add insult to injury, I had to drive two cars (hers and the 928) 60 miles round trip at a prohibitive fuel cost. The result? Priceless.

I'm still trying to figure out what "rear A/C" means. AFAIK, I only have the one compressor and a single A/C head. The cabin is small. What does "rear" mean?

Thanks,

Pfc. Parts

Mike, thanks for clarifying that and detailing your procedure, helps a lot.

I've bought a vacuum pump and gauges, I'll add an A/C flush gun tomorrow.

Some of the parts probably need to be removed just to replace old o-rings and seals, but knowing the major components can be flushed in place will save me a great deal of time.

Regards,

Pfc. Parts

On a related note; does anyone have advice on how to bench test a compressor? At this point I only know my compressor is leaking "on top" somewhere, which I assume means on one of the two hose connections. My hope is this can be corrected by replacing the o-rings. Once's that's done, is there a reliable way to test the thing while it's off the car?

You can assume I have a compatible vacuum pump and gauges.

Thanks,

Pfc. Parts

David I'd probably go that direction if I had a later model car designed with R134a in mind (as the S4s were), but there are too many components that would need replacing on an '85.

Then there is my desire to keep this car as close to stock as possible. I've known her for 30 years now; I kind of like her the way she is.

Pfc. Parts

This isn't a political forum.

z driver 88t

Yes, understood. Just thought if part of the concern over to convert or not was R12 availability, that is not really an issue. I used to mistakenly think that R12 was unobtainable unless you were some sort of authorized repair shop and shops love to make you think this.

Both of my two local 928 mechanics tried to steer me away from rebuilt OEM compressors on my 84S because they had mixed experiences with rebuilt units - some good and reliable, others not so much. Both recommended the Griffiths kit since it is an "all inclusive bolt in" package.

However, I understand you may be going for an all original car. Best of luck in whatever route you go.

Pfc. Parts

Chris - I am making every reasonable attempt to keep this car as close to stock as possible, the other car I don't care about in that respect, in fact I plan to remove the A/C system from it completely.

If I have to replace the compressor I may consider a 134a conversion, however at this point the compressor itself isn't suspect. I would like to hear from anyone who has a novel method for bench testing one for leaks.

John Speake

Hi Scott, my air con compressor leaks at the shaft seal (easily spotted after dye was added to the system ) and I have bought a seal kit from CenturyAuto Air. They also have "how to" videos on YouTube.

You can see the videos here and also a link to their website here:-
https://www.google.com/search?q=reseal+10PA+20C

I shall be resealing my compressor in the next couple of weeks.

Pfc. Parts

Great reference John, thanks.

Pfc. Parts

John - again thanks, this is exactly what I needed. Rather than jerry rig a bench vacuum test, I think it would be more prudent to simply replace the seals. Very good!

Regards,

Pfc. Parts

Another fine writeup on this subject published on this site I didn't find until I used Google:

https://rennlist.com/forums/928-foru...uild-pics.html

Pfc. Parts

I contacted Jennifer at Century Auto Air and she let me know that the 1985 uses a Nippon Denso 6E71 rather than the 10PA series used in the later model cars. They do stock complete kits for that compressor although they don't list them on their web site.

Pfc. Parts

Another fine video on the subject of replacing the shaft seals on the older model compressors found on the '85 titled:

"Common replacement techniques for older Denso compressors using 2-piece carbon-steel seals. Procedures apply to:
6P Series
10P 13/15/17/20 Series
Parts shown in this video can be purchased at our website www.centuryautoair.com on our Catalog page under "Compressor Parts":
SK-753 - no extractor lip, works with all types
SK-740 - has extractor lip for use with front loading seals only"


According to Century and several OE retailers for the '85 928 it has a 6P series compressor in it.

Pfc. Parts

Hi Chris -

I just wanted to follow up (for the record as it were). I already hold an EPA 609 Certification, however (and I'm not a lawyer, I just play one on TV) I believe if you read the CFR's carefully you'll find a 609 is only required for MVAC technicians who work on these systems "for compensation", i.e. they get paid to do it. In this example I'm restoring my own car and I don't think I'm even required to have it since I pay myself very little...