A6 seal leaks!!

[Domenic T.]

Was on the CF and something was pointed out that may be the false cause of many front seal leaks by a guy named Neal.
You know the manual says a little leak is OK! I say NO.
He pointed out that a over tensioned belt can cause a leak. Yes, the pulley bearing is one, enclosed in grease with 2 rows of roller balls.
When it is pulled to one side with a over tightened belt, the clutch will move from shaft center every revolution, (the V in the pulley is not exactly on center with the belt). The pulley being pulled toward the over tightened side will cause the clutch engagement to move the shaft part of the front seal engagement causing it to slide over the seal face.
From what I remember the belt tension was 3/4" up and down.
Another leak found was new over packed new bearings. With no place to go,(over packed) the grease will cause hydraulic heat which will cause part of the grease to turn to OIL. The oil will appear as a oil leak from the front seal.
Have a leak, see if pulley has any side movement. If so it may be the oil in the grease leaking out of the enclosed bearing.
The A6 was never meant to be a cycled compressor by design... Engaging at high RPM, or adding a cycling kit will ruin the clutch and cause leaks..
When the evap froze over (comon) there was a drain tube under the evap. Simply the operator of the car was to TURN the A/C off and let the evap melt and drain.
If we are going to run these old cars with A/C we have to do manual work and monitor the system.
One other point is that the China bearing grease will leak about a teaspoon of oil before the space between the balls will not heat up the bearing. The grease was only meant to lube the balls, not smother them.

Dom

[Mark E.]

Re: A6 seal leaks!!

Dom,

What you say makes sense. But are any of these causes unique to A6?

[Gary J.]

Re: A6 seal leaks!!

Dom, are there any USA bearings made that are of better quality that will work? My son was working with Koyo bearings which is the the old Timkin bearings until he was laid off. Koyo is a Japanese Company.

[Joe L.]

Re: A6 seal leaks!!

Dom, are there any USA bearings made that are of better quality that will work? My son was working with Koyo bearings which is the the old Timkin bearings until he was laid off. Koyo is a Japanese Company.

Gary------


I am unaware that there is any connection between Timken and Koyo.

[Keith B.]

Re: A6 seal leaks!!

So what seal do you recommend?

[Michael J.]

Re: A6 seal leaks!!

Thanks for this info, I added a cycling kit so I guess I need to watch it closely.

[Mark E.]

Re: A6 seal leaks!!

Thanks for this info, I added a cycling kit so I guess I need to watch it closely.

Several years ago, another A6 rebuilder also told me the A6 does not hold up well with a cycling kit installed. No experience personally.

[Terry M.]

Re: A6 seal leaks!!

Several years ago, another A6 rebuilder also told me the A6 does not hold up well with a cycling kit installed. No experience personally.

Years ago I had Suburban (1978 IIRC) with a Cycling Clutch Orifice Tube system with A6. I even added a rear Evaporator to the vehicle (an option at the time), and that original A6 held up beautifully. While one anecdotal example does not prove much of anything, my personal experience would lead me to be skeptical of the report of reduced life due to cycling.

In any case replacing the clutch, if that is the failure mode, is not all that difficult with the proper tools.

[Domenic T.]

Re: A6 seal leaks!!

Mark,
I think they are directly related. If the pulley moves side to side when checking for bearing wear. The clutch will be out of center as it is attached to the shaft. The shaft has 1/2 of the 2 piece seal on it and this will cause the 2 seal faces to slide.

Dom

[Domenic T.]

Re: A6 seal leaks!!

Gary,
Joe lucia likes Jap bearings and my tech friend says he orders bearings for severe duty when he builds machines.
My best guess is that the price is way up there. I remember the 3/4 up and down rule along with the belt MUST contact at least 1/3 of any pulley.
In most shops when a belt is installed it is over tightened because it will stretch. The days of having a customer come back to get the belt adjusted after it stretched (broken in) are gone. So are the days of removing the exhaust manifolds to re-torque the heads.

Dom

[Domenic T.]

Re: A6 seal leaks!!

Keith,
I am ceramic all the way. They make 2 versions. Ceramic against ceramic, and ceramic against carbon steel. I had a few problems during pressure tests with the ceramis against ceramic. The ceramic against carbon steel was on the early compressors.

dom

[Domenic T.]

Re: A6 seal leaks!!

Terry,
What I see is a severly worn clutch and pulley. As you know the clutch is metal to metal and cycling wears them to the point of the pulley de-laminating and in some cases the clutch getting so hot the rubber de-laminates from the clutch. I am a believer that engagement should be done at low RPM. Cycling happens at any RPM. I saw sparks from the pulley and clutch when engaged at about 3,000.

Dom

[Domenic T.]

Re: A6 seal leaks!!

Keith,
Most likely the lip seal will solve the problem for limited use. The way the cars are driven one said he had a lip seal last 4 years. Ceramic seals, seal with 2 O-rings, One on the shaft and one in the front cover. Replacing the front seal failures are due to a dirty shaft or dirty O-ring surface in the case half. I think it is almost impossible to get O-ring surfaces clean enough to get a proper seal with the shaft in place. I buff the shaft and use a dremmel with a SS wheel to clean the case O-ring surfaces, then wipe with the O-ring channel with a Q tip and oil. Also, I have never replaced a seal with the shaft in place. Another is that the ceramic seal comes with a black O-ring and not a green. There is spring pressure against the O-ring that distortestes it. The shaft part of the new seal must come apart and replace the new black O-ring with a new green O-ring dipped in oil.
The old assembled clutches were a wobble at best. That's why they say .022 to .056 clearance between clutch and pulley. The clutch (installed) must not be closer than .022 clearance, or farther clearance distance than .056 at any point, meaning a variable distance narrow (.022) point of clutch to the most widest (.056).
The new repo clutch hubs are right on, but are not cosmetically the same.

Dom

[Gary J.]

Re: A6 seal leaks!!

Dom, do you have the manufacture of the bearing, part number, size, and dimensions of the bearing? Would like to see what my son could find out about it.

[Keith B.]

Re: A6 seal leaks!!

Dom the A6 in my dads 67 427 car was rebuilt and the seal lasted 6 months. So we been looking for a local shop who is willing to work on it and trying to find one that will last longer.