Clutch Master Cyl. and Differential leaks

[zm@mhcnet.att.com]

	Two problems have started on my '87 5000CSQ recently (56K miles
on the odometer now):

1. Leak in the Clutch Master Cylinder.  The brake fluid (the hydraulic
clutch is connected to the brake reservoir) is leaking inside the car
near the clutch pedal. I determined that its not just a leak from a loose
line fitting. So I either have to change the cylinder or rebuild it.
Audi doesn't sell a rebuild kit and the dealer will only install a new
master cylinder ($172 from the dealer, plus $87 labor, $138 from Shokan).
I have bought a Wagner rebuild kit from the aftermarket car parts
store for $17 and plan to rebuild the cylinder myself. Has anyone done this
before? The Bentley manual recommends "pressure bleed only". I don't have a
pressure bleeder but may be able to fashion one with my air compressor
if I can find a cap of the right size to fit onto the brake fluid reservoir.
Any pointers, suggestions or gotchas?

2. Leak in the rear differential axle seal (right side). I was alerted to
this by a rumbling noise that started a few weeks ago. Examination revealed
the leak. I topped up the differential but the noise didn't go away. A
bearing in the differential (on the drive-shaft side) is worn and is causing
the noise. I took the car to the dealer to confirm my diagnosis which he did.
But - here's the clincher - the dealer claims that their mechanics are not
trained nor have the special tools to change this bearing. They say that they
have never had to take apart a rear differential on a quattro before. They
have changed the axle seals previously but not the bearings. I am tempted
to do the job myself. The parts are available from the dealer and the Bentley
manual is reasonably descriptive of the bearing and seal replacement procedure.
The jobs looks straight-forward but requires the bearing to be pulled/pressed
on/off. Again, any pointers or suggestions?

I am a bit disappointed that these two problems have started on the car
at such a low mileage. One does not expect leaky master cylinders or
differentials at 56K miles (I won't complain about the slow-leaking steering
rack that I haven't fixed yet).

Any help will be appreciated. Thanks in advance.

Zafer
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Zafer Mehmood					AT&T Bell Laboratories
zm@mhcnet.att.com				Murray Hill, NJ