a6 compressor reseal issues
Thread Starter
Instructor
Joined: May 2018
Posts: 177
Likes: 35
From: pa
a6 compressor reseal issues
I am working on getting the ac system back in service on the 71.i bought a reseal kit with the newer style double lip seal thinking maybe better for a car that does not get driven 6 months out of the year.tore the compressor down and installed the seal as shown by a vendor on you tube.put the compressor back together and put 100# of nitrogen in the system for a leak test. the seal is still leaking! has anyone had any luck with the double lip seal sealing good?maybe I should not have put a 100 pound test on it or maybe I should just put the older 2 piece seal back in it. shaft looks good with almost no wear .I did not spin the compressor prior to leak test. does it need oil up there to help seal like the old style seals? thanks for any thoughts
Racer
Joined: Jul 2007
Posts: 430
Likes: 7
From: Florida
Did you check the run out on the shaft? It has to be really tight, I forget the tolerance it's been a while.
Anyway, I did the same on my '72 A6 and it ran about a year with no leaks at all, thought it was golden. Now it slings a little oil just like the rest. I guess if I do it again I would just put a ceramic seal back in and make sure the system is totally clean and flushed. I think the shaft tolerance is critical.
Good luck,
Anyway, I did the same on my '72 A6 and it ran about a year with no leaks at all, thought it was golden. Now it slings a little oil just like the rest. I guess if I do it again I would just put a ceramic seal back in and make sure the system is totally clean and flushed. I think the shaft tolerance is critical.
Good luck,
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
All seals need oil when they are installed. I used a double lip seal on my R4 and it leaked then started slinging oil after about 18 months, only drove maybe 4 months. Went back to the ceramic seal and it’s holding so far.
ps. You don’t need all the special installation and removal tools for the seal, just the clutch removal and installation tools.
ps. You don’t need all the special installation and removal tools for the seal, just the clutch removal and installation tools.
Last edited by REELAV8R; Jul 16, 2018 at 10:43 PM.
Thread Starter
Instructor
Joined: May 2018
Posts: 177
Likes: 35
From: pa
I checked the shaft for movement and it seemed like it was tight. I took my old compressor manifold that I replaced because it is 47 years old and cut the hoses and plugged them. bolted it back on the compressor on the bench and sat it on end and put a nitrogen charge to it. with soap I could see the leak was not at the shaft but on the outside of the seal getting by the O ring.tore out the seal and cleaned inside the shaft again and replaced the o ring.put it back together and now it is holding a 100# of nitrogen.i suspect there might have been a piece of ceramic seal in the O ring groove. anyway had a pump on it all night and going to put gas back in it today and see what happens.i am going to buy one of those GM compressor clutch shields and keep it on for a while in case it starts slinging oil again.
Racer
Joined: Jul 2007
Posts: 430
Likes: 7
From: Florida
I checked the shaft for movement and it seemed like it was tight. I took my old compressor manifold that I replaced because it is 47 years old and cut the hoses and plugged them. bolted it back on the compressor on the bench and sat it on end and put a nitrogen charge to it. with soap I could see the leak was not at the shaft but on the outside of the seal getting by the O ring.tore out the seal and cleaned inside the shaft again and replaced the o ring.put it back together and now it is holding a 100# of nitrogen.i suspect there might have been a piece of ceramic seal in the O ring groove. anyway had a pump on it all night and going to put gas back in it today and see what happens.i am going to buy one of those GM compressor clutch shields and keep it on for a while in case it starts slinging oil again.
Did you use a shaft seal protector when you installed it?
Yes you have to lube the seal, I actually put it on backwards and then took it off again, makes install easier
2 O rings came with mine, I used the smaller diameter one
Did you take out both parts of the old ceramic seal?
Sorry if you already know about these, just checking!
Burning Brakes
Joined: Oct 2001
Posts: 918
Likes: 198
From: TX
A few questions for you...
Did you use a shaft seal protector when you installed it?
Yes you have to lube the seal, I actually put it on backwards and then took it off again, makes install easier
2 O rings came with mine, I used the smaller diameter one
Did you take out both parts of the old ceramic seal?
Sorry if you already know about these, just checking!
Hope this helps. A/C is worth it! 102 here in north central Texas today!
VS
Thread Starter
Instructor
Joined: May 2018
Posts: 177
Likes: 35
From: pa
I did use the seal protector to install the double lip seal . I think my problem was I beat out the old 2 piece seal and shattered the ceramic seal. I just tried to wipe out the inside of the shaft and I left a peice of something in the O ring groove. pulled it apart again and used a pick to clean out the o ring groove. reinstalled everything and it sealed. put gas back in it this morning and its blowing cold air! however it does seem to put a fair amount of load on the motor at idle. had to step up the idle speed a little.waiting for an adapter to put on the 3/16 hi side fitting so I can check it with gauges.the old manifold had 1/4 taps on hi and low side. new one has 1/4 tap on low side and 3/16 on hi side?. not sure why they did that. thanks for all of your input.
Burning Brakes
Joined: Oct 2001
Posts: 918
Likes: 198
From: TX
I did use the seal protector to install the double lip seal . I think my problem was I beat out the old 2 piece seal and shattered the ceramic seal. I just tried to wipe out the inside of the shaft and I left a peice of something in the O ring groove. pulled it apart again and used a pick to clean out the o ring groove. reinstalled everything and it sealed. put gas back in it this morning and its blowing cold air! however it does seem to put a fair amount of load on the motor at idle. had to step up the idle speed a little.waiting for an adapter to put on the 3/16 hi side fitting so I can check it with gauges.the old manifold had 1/4 taps on hi and low side. new one has 1/4 tap on low side and 3/16 on hi side?. not sure why they did that. thanks for all of your input.
I too shattered the ceramic seal trying to get the sob out.
Fun being coooool!
VS
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Burning Brakes
Joined: Aug 2013
Posts: 1,071
Likes: 322
From: palm springs ca
This is only my opinion on the double lip seal. The ceramic seal does not contact the shaft. Half is on the shaft and the other on the front plate.
The double lip contacts the shaft and the shaft turns against the rubber. If you have noticed what the double lip front engine seal does to the harmonic balancer you will understand why I don't use them. The front seal on the engine does not have pressure on it (crank case or oil) and it wears the balancer as time go's on.
The compressor has mega pressure on it and that pressure is against the rubber that the shaft is turning in, (higher the pressure the harder the contact), so the life span of the new style seal is limited.
Because of the pressure is why the A6 did not use a seal that contacts the shaft. Sure the new seal is a 1 piece and easier to install, but the 2 piece ceramic seal is by far the one that will out live us.
There are 2 kinds of ceramic seals. One is ceramic against ceramic and the other is ceramic against hardened steel. the ceramic against hardened steel is the one to use.
I have never seen wear between the 2 part ceramic seal. the leaks are from the O-rings that seal each half of the ceramic seal. Rust, and hardening of the O-rings is what usually happens. Also when replacing the O-ring surfaces have to be spotless and undamaged. I buff all the O-ring surfaces which would be almost impossible with the shaft in place. The 2 part ceramic seal has a spring that puts a few pounds pressure against the mating surfaces.
The double lip contacts the shaft and the shaft turns against the rubber. If you have noticed what the double lip front engine seal does to the harmonic balancer you will understand why I don't use them. The front seal on the engine does not have pressure on it (crank case or oil) and it wears the balancer as time go's on.
The compressor has mega pressure on it and that pressure is against the rubber that the shaft is turning in, (higher the pressure the harder the contact), so the life span of the new style seal is limited.
Because of the pressure is why the A6 did not use a seal that contacts the shaft. Sure the new seal is a 1 piece and easier to install, but the 2 piece ceramic seal is by far the one that will out live us.
There are 2 kinds of ceramic seals. One is ceramic against ceramic and the other is ceramic against hardened steel. the ceramic against hardened steel is the one to use.
I have never seen wear between the 2 part ceramic seal. the leaks are from the O-rings that seal each half of the ceramic seal. Rust, and hardening of the O-rings is what usually happens. Also when replacing the O-ring surfaces have to be spotless and undamaged. I buff all the O-ring surfaces which would be almost impossible with the shaft in place. The 2 part ceramic seal has a spring that puts a few pounds pressure against the mating surfaces.