Re: differential leak; pressure accum.

[zm@mhcnet.att.com (Zafer Mehmood [209])]

> 
> 1. My '89 100q rear differential has a slight leak.  An Audi mechanic told me 
> to leave it alone -- just check the level once in a while -- that most of them 
> do this but they don't leak very much!  This surprised me -- Is anyone 
> familiar with this syndrome and with this advice?  Dealer says it's about a 
> 300 USD repair.  Checking the level is a nuisance because one must remove a 
> heat shield to get at the filler plug, and even then the plug is hard to reach 
> (I think there's a special tool for it).

I wouldn't ignore this leak. My '87 5KTQ had a similar leak from the rear
differential. The oil seal at one of the axles (where the axle connects to
the diff) was leaking. The leak went unnoticed for sometime. It was hard
to see; just some wetness on the diff, but covered partly by the shield.
Bottom line was that the low fluid level destroyed a differential bearing.
This showed up as a rumbling noise. I recommmend you check and fix the
leak. Replacing the seal is much cheaper than replacing a bearing (more
labor) or the differential itself.

Until you fix the leak, make sure that the oil level is maintained by
topping up (synthetic fluid I believe). I think the filler plug takes
the standard 17mm hex (allen key) that is the same as the center diff/
manual trans plugs. I bought my hex wrench at Sears.

> 
> 2.  I need a brake pressure accumulator.  The dealer quoted about 350 USD for 
> the part and an hour of labor to install.  Is there any point looking for a 
> cheaper alternative, i.e., non-Audi part or used part?  

You can buy a German-made pressure accumulator from PAP or Halsey Imports
for much less than the Audi dealer (around $200 or so). These are just as
good as the dealer ones; no point paying 1 1/2 times. Replacement is easy;
takes about an hour; procedure was posted here I believe.

Zafer