Quote:
Originally Posted by njsteve
The sad thing is I have been through a dozen rebuilders (NAPA, too) and even brand new Delco units and they all eventually seep oil from that front seal. This covered the gamut from regular passenger vehicles, trucks and the recent Pontiacs. This particular one held a perfect vacuum for an hour with no leakdown whatsoever pror to filling it with the proper amount of R12. We did the proper oil seal run in by hand turning the compressor clutch for a couple minutes to lap it in. I even pulled the vacuum down, and then it held the vacuum for 2 months while I did other work to the car prior to the refilling day.
A buddy of mine was a GM line mechanic for 20 years back in the 60s and 70s and is still a great mechanic. He is the one that worked on this car's system. He laughed when I asked him to place a bet as to when the oil would start leaving the telltale line under the hood. He said that in all his years of working on A6 equipped cars, he never found an original compressor or even a replacement seal that would not eventually leak oil from the front hub. Some of it has to do with the rebuilders that soak that piece of felt/sponge that is in the center of the hub. The sponge is supposed to hold the oil in place and keep it from wicking out onto the clutch, but most rebuilders oil the sponge first, so it gets oversaturated and just throws oil out forever.
Hopefully this car has the oiled up sponge situation and not an actual leak. It stills blows really cold. I just get irritated because I really notice the oil droplets on a flat black underside of the fiberglass hood.
I will check out NAPA and see what they have. The problem is my buddy doesn't have an R12 recycling machine anymore so I'd be wasting the R12 fill in order to swap out to another (probably leaky) compressor.
I will say that maybe it has to do with the higher pressures that R12 makes in the original system. My Gramma's 75 Esprit runs an A6 but is filled with Freeze12 which was a replacement refrigerant. With this refrigerant you only used 2/3 of the factory fill spec, so it is not running at the factory high pressure. That car has an almost nonexistant oil throw off and has held the charge for 5 years now.
70RAIII, I really do appreciate your technical input. You have helped me out a bunch over the years with brake and alternator parts/repairs. You don't happen to have a "pre-run in" compressor sitting around do you? :-)
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Steve.. don't have one I would use. I have a couple NOS units, but truth betold I think I would rather use a recently rebuilt unit.. NAPA is a good deal, and like I said.. they will honor the warranty is the seal is leaking.. As far as your system having higher pressures, R12 runs close to 134 pressures, and 134 is actually the higher.. If your system held vacuum for so long, then I say you over pressurized the system and the front seal blew.The front seal accesses oil from the same place as the main system, so it is all connected...I have always put a 1/2 can short of suggested capacity on the R12.. If you are getting high side pressures over 220ish/low side >30, you have most likely too much oil or Freon installed.As far as shields being made..I assure you GM did not make a oil catcher vs fixing an engineering issue causing the leak. They just don't do that and thinking any car manufacturer would sell new warranted cars with a known leak.. just didn't happen.. The shields were for another reason, not for oil spray..