AC compressor case leak

Been working on my GT for a DD. Had to deal with thrown rod, sat for a couple of years, put in replacement short and got it working.

Finally got around to working out the electrical problems with the a/c to find it had leaked down 80%. I have been doing my own a/c work on many cats for many years, so figured I'd find and fix this. However, the leak sniffer pointed to the compressor, and the dye test showed a leak at the case (not the shaft seal). It appears the case has 2 end caps with likely a large oring sealing the cap.

Staying away from the leak sealers, but figured I'd find some way to swell/condition the orings before I replace the compressor.

Anyone run into this problem and been successful with recovery?

91 GT. Converted to r134 some 15 years ago. Probably on 2nd compressor, 4th condensor etc.

It's not clear to me where on the compressor you are saying your leaks are. Are they at the refrigerant line connections to it? Or are they around the housing seams of the compressor body? Compressor body seams have seals also, and they can leak when old. They can also leak on an R12 original system that went to R134a and did not get all the R12 oil out first (if not done right, these refrigerant conversions can cause this situation also).

There are sources for ST185 remanufactured compressors around, and new compressors as well. If you are setting yours up for a long-term DD, getting a replacement compressor may be in your best interest.

I’ve never used any type of leak stop on A/C equipment. If you’re ok with A/C work you could rebuild it yourself. Easy to do and parts are available. With the money you save you could get your license and put it back to R12.

https://youtu.be/CD5lLC5v6PE

And if you don’t want to rebuild yours buy a new unit, not a reman. The reman units you buy at parts stores are pretty crappy. Last one I bought for my old Chevy truck was full of rust!

I have (4) 5th Gen Celica's in the family, (2) of them are ST185's. All still on R12. Have quite a bit of stock of R12 yet. Great stuff, and lower pressures tend to keep the potential for leaks down a bit. I'd always prefer to stay with R12 if possible, but not many service places around carry the stuff anymore (if you're not into doing your own work).

Thanks all.

I had converted the system years back after a minor accident that took out the condensor figuring r12 would become hard to find in the future.

Been running the system at r12 pressures with diminished cooling and was fine with it (except those 104 days driving into the sun.

I've repaired many a leak, I was surprised to see 2 of the 3 case orings go vs a shaft seal or manifold seal.

I'll try a ester shot to see if it does anything, but will likely have to do the reseal approach.

A little quick question I would like to ask here. When I did a heart and lung transplant on my Celica I replaced all the O rings
on all the AC pipes with green ones (R134a type). What has worried me is how hard do you tighten the nuts after? (I mean when you
rejoin the couplings) If you do them real tight you flatten out the O ring, to a flat washer about as thick as a piece of paper (thick paper lol)
Oh I haven't regassed the system yet.

Typically 8-22 ft lb depending on the size. If using a crows foot, you'll need to adjust the torque setting to compensate for the extra length.

In some circles, it's finger tight plus another 1/8-1/4 turn.

Also, be sure to lubricate with mineral oil to ensure the oring does not stretch or bind.

UPDATE:

Tried the oil injection, no help. Decided to go the rebuild route.

On disassembly, noticed the compressor had probably 50% of loose oil. So, I think, the 2 year sit of the car allowed the oil to settle on the bottom of the compressor, allowing the top of the case seals to dry out. The seals were variable in pliability probably matching oil location.

Rebuild, vacuum, recharged, been working great now for 3 weeks - knock on wood.