[70RAlll]

Steve-

Nice construction on the shield..But I am confused?? All A6's leak? I don't think I agree with that statement..How would GM have installed 100,000's of this design A/C compressor over the years if it was a always leaking?? I think if they are not rebuilt or prepped correctly they will leak. I have installed and charged many many A6's.. I too have had A6's that leaked, a few times went through 3-4 different compressors until getting one that does not leak.. NAPA sells one with warranty for something like $79, use the rear plate from your original and it is dead on. There is a procedure to get the seal oiled before charging, also pulling a vacuum for an hour or so will help seal initially, plus will show any leaks before wasting valuable R12 charging.....If your front seal is leaking oil, then the entire system is exposed to the outside air..You will eventually leak out your Freon and your oil-you cannot replace the sprayed oil unless you open and de-charge the entire system- the oil is not separate from the Freon....So the shield may help for a 100 mile trip, but this kind of fix is guaranteeing you will end up with trouble down the line in the form of a burned up compressor or rusted inside of the A/C system.. Especially confusing when you consider a NAPA rebuilt unit is $79 with a warranty.. Don't get it..Would be like putting a shield on an oil leak that is hitting the exhaust but not fixing the leak?? Trust me..you can get an A6 that does not leak..

[njsteve]

Originally Posted by 70RAlll

Steve-

Nice construction on the shield..But I am confused?? All A6's leak? I don't think I agree with that statement..How would GM have installed 100,000's of this design A/C compressor over the years if it was a always leaking?? I think if they are not rebuilt or prepped correctly they will leak. I have installed and charged many many A6's.. I too have had A6's that leaked, a few times went through 3-4 different compressors until getting one that does not leak.. NAPA sells one with warranty for something like $79, use the rear plate from your original and it is dead on. There is a procedure to get the seal oiled before charging, also pulling a vacuum for an hour or so will help seal initially, plus will show any leaks before wasting valuable R12 charging.....If your front seal is leaking oil, then the entire system is exposed to the outside air..You will eventually leak out your Freon and your oil-you cannot replace the sprayed oil unless you open and de-charge the entire system- the oil is not separate from the Freon....So the shield may help for a 100 mile trip, but this kind of fix is guaranteeing you will end up with trouble down the line in the form of a burned up compressor or rusted inside of the A/C system.. Especially confusing when you consider a NAPA rebuilIit unit is $79 with a warranty.. Don't get it..Would be like putting a shield on an oil leak that is hitting the exhaust but not fixing the leak?? Trust me..you can get an A6 that does not leak..

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? :-)

[70RAlll]

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? :-)

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..

[njsteve]

Do you have a part number for the NAPA $79 compressor. Their website prices start at $249.

[71formula455]

Steve, I didn't get a chance to say hello at PY this weekend, but wanted to say congrats on the hard work your car looks great.

[70RAlll]

Originally Posted by njsteve

Do you have a part number for the NAPA $79 compressor. Their website prices start at $249.

I found a couple for $199.00 on the website..Look up 1973 Chev Truck or 1980 Buick Wagon.. These off the path vehicles will be cheaper. Plus, NAPA has 2-3 different options for compressors. One is a standard 2 year warranty, the 6 month warranty is enough and is the cheaper unit..If NAPA cannot find one using their computer, ask for their compressor book. Then look up compressors by picture. You will find a page or two of A6's at various prices- you will have to rattle off part numbers while they look up prices.....A6's seem to go bad almost immediately if they are going to..Also, even if you spend a couple hundred, you will get a non leaking unit that will be better.. Did you use the correct viscosity of oil? Plus did you clean out the dryer and muffler??They need to be both newly cleaned inside with new dissectant installed..

[njsteve]

Muffler cleaned put and a brand new receiver dryer, and filled with correct modern oil for use in R12 units, after draining unknown amount of prexisting oil in compressor. System works fine (and has for a month or so since being filled). It just leaves the oil film under the hood. When it was filled, the pressures were well within midrange of the spec and nowhere near the max. If I recall correctly, he filled it to the point where the bubbles in the sight glass just disappeared, which was less than the actual fill spec. I was behind the wheel at the time checking the outlet temps.

As an added bonus, the oil was dispersing on the exact same plane as the power steering pulley groove on the crank pulley...so you guessed it - extra squeeling from the power steering belt. Its definitely the ps belt as I removed all the belts to isolate the squeel and that was the only belt that made the noise.

[70RAlll]

Originally Posted by njsteve

Muffler cleaned put and a brand new receiver dryer, and filled with correct modern oil for use in R12 units, after draining unknown amount of prexisting oil in compressor. System works fine (and has for a month or so since being filled). It just leaves the oil film under the hood. When it was filled, the pressures were well within midrange of the spec and nowhere near the max. If I recall correctly, he filled it to the point where the bubbles in the sight glass just disappeared, which was less than the actual fill spec. I was behind the wheel at the time checking the outlet temps.

As an added bonus, the oil was dispersing on the exact same plane as the power steering pulley groove on the crank pulley...so you guessed it - extra squeeling from the power steering belt. Its definitely the ps belt as I removed all the belts to isolate the squeel and that was the only belt that made the noise.

Yea Steve...you need to get that leak fixed...