Is this AC compressor a lost cause - PeachParts Mercedes-Benz Forum

johninva · #1 08-11-2009, 08:54 PM

Decided not to guess at how much oil to add, and removed the compressor to drain and refill with oil. the biggest leak found with the leak detector was at the back of the compressor. When I got it removed I found this gouge in the body around where the lines connect up to it, the o-ring was deformed somewhat into the gouge. Kind of hard to see in the blurry photo. Coincidence ? or is this why it was leaking there ? would be a shame if I had to replace the compressor cause it looks like it has been replaced recently. Seems like this defect may have come from the factory? Compressor is relatively big $

Thought maybe about trying to clean and fill the gouge with some JB-Weld.
Thoughts, ideas, suggestions, please.

jef d · #2 08-11-2009, 09:20 PM

if its a r-4 I have a new rebuilt in the box I can sell you at a good price ! thanks j

leathermang · #3 08-11-2009, 09:45 PM

If you are dealing with an R4 then you have missed a basic concept on the oil....
The R4 does NOT have an oil sump like most other compressors...
this is why the oil miscibility question as to alternative refrigerants is very important... it only gets lubed from what is constantly running around the system dissolved in the refrigerant...
So to get the proper amount you still need to flush the entire system and put the proper amount spread around in several places before starting it up...

DocSarvis · #4 08-11-2009, 10:09 PM

To answer your question. Yes I think you can repair the gouge. That is not the holding surface per-say. the o-ring should seal fine after you fill the gouge with your choice of filler. Thanks

lietuviai · #5 08-11-2009, 10:34 PM

I wouldn't risk a poor connection. The R12 can cost more than the compressor. These compressors aren't that expensive.

Cervan · #6 08-12-2009, 01:56 AM

i cant tell if thats the low or high side. If its the low, i would say throw some jb-weld on it and go for it. if its the high it might be kinda risky, for one it gets very hot for long periods of time on the hot side, and the pressures are very high. I would just go get a rebuilt one its worth the peace of mind.

#7 08-12-2009, 08:01 AM

Quote:

Originally Posted by lietuviai

I wouldn't risk a poor connection. The R12 can cost more than the compressor. These compressors aren't that expensive.

Either you have found an EXTREMELY cheap source for a compressor, or you are getting ripped off BADLY on R12.

The going price for R12 these days is about $15 a pound, only about half again as expensive as many sources for R134a.

OP,

BTW, as long as there are no sharp edges in all that o-ring groove mess, I think that an o-ring will seal okay. After installing everything, evacuate and see if it holds vacuum for an hour or so, THEN give it however much R12 it will take and then beg, borrow or buy a sniffer to test it. If it is not leaking, then charge it on up and sniff again with the system running so that it is under normal high side pressure.

Johnt49 · #8 08-12-2009, 11:43 AM

I'd put it back in using the green o rings designed for the GM cars, then charge it with 134a for testing purposes. 134a isn't compatible with mineral oil, but will be ok to run long enough to test for leaks. The part that is missing on your compressor is not a sealing surface, but could let the o ring "bulge out" in that area. Only way to know for sure is to give it a try. If it holds, then dump the 134a and pump it down for at least 1 hr and charge with R12.

leathermang · #9 08-12-2009, 11:54 AM

Johnt49,
YOU have just suggested he violate EPA regulations bigtime... but more importantly UNNECESSARILY...
a quick search ON THIS FORUM would find the correct EPA approved ( not to mention the stupidity of mixing the wrong refrigerant with the oil in the system )...
method which does allow the dumping of the test charge..
YOU REALLY NEED TO DO MORE RESEARCH BEFORE ADVISING OTHERS ON THIS SUBJECT.

Johnt49 · #10 08-12-2009, 12:30 PM

Quote:

Originally Posted by leathermang

YOU have just suggested he violate EPA regulations bigtime YOU REALLY NEED TO DO MORE RESEARCH BEFORE ADVISING OTHERS ON THIS SUBJECT.

Take it for what it's worth, but DON'T PREACH TO ME as the moral authority on the subject!! If you want to play big brother, maybe Obama has a czar position for you.

#11 08-12-2009, 01:50 PM

leathermang was not "preaching." He was merely pointing out to both you and whatever innocent person that might be reading this thread that you are suggesting violation of Federal law. Someone could easily read what you wrote and unknowingly break Federal law.

If you wish to violate Federal law, I would suggest that you not advertise even so much as your willingness to do so on a public Forum. As you properly pointed out, there are plenty of Big Brother Czars watching.

Matt L · #12 08-12-2009, 02:08 PM

The penalties are quite severe, especially given that most DIYers don't even know the rules. They're geared towards making it financially unsuitable for shops to do it. But if someone turns you in, they get a cut of the massive fine. They won't have to share your jail cell with you, however.

Johnt49 · #13 08-12-2009, 02:31 PM

No where in my post do I suggest violating federal law. I have not suggested circumventing any EPA regs. If you're equating "dump" with venting to the atmosphere, that's a misinterpretation on your part. My only intent was to verify the integrity of the system with easily obtainable 134a before installing the much more valuable, more destructive to the atmosphere & harder to obtain R12.

Matt L · #14 08-12-2009, 02:46 PM

Quote:

Originally Posted by Johnt49

No where in my post do I suggest violating federal law. I have not suggested circumventing any EPA regs. If you're equating "dump" with venting to the atmosphere, that's a misinterpretation on your part. My only intent was to verify the integrity of the system with easily obtainable 134a before installing the much more valuable, more destructive to the atmosphere & harder to obtain R12.

Most people would indeed equate "dump" with venting, but thank you for the clarification.

#15 08-12-2009, 03:53 PM

Nothing like some last minute CYA to fend off the lawyers.