Re: Brake pressures

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

> My problem is with a '91 TQ wagon (20V) with 43,000 mi.  Brake pressure
> light comes on in the AM for a period that depends on how long it has been
> since last run; up to 30 sec or a minute or more.  
[stuff deleted]
> 
> However, and this is the peculiar part, said dealer says he cleaned the
> filter screen and that cured the problem.  Indeed it did until a month
> after the warranty expired and nobody wants to see me again.  Dealer of
> course says whatever was wrong was fixed and this is a new problem!  I have
> tried cleaning the screen again to no avail.
> 
What screen did the mechanic clean? The plastic one in the reservoir
or the small one in the high pressure hose fitting at the pump? 

> I have read the preceeding commentaries on the symptoms of death of the
> accumulator.  Am I seeing an incipient demise?  Is the check valve integral
> to the accumulator or a separate part?  I admit to not having checked the
> parts fiche.  Any advice out there?
> 

The symptoms you describe do indicate a failing Pressure Accumulator (PA).
The check valve is integral to the PA and you have to replace the whole
accumulator although only the check valve may be bad. The PA costs about
$200 aftermarket and takes about an hour to replace.

If you've got only 43K miles on the car, I suggest you speak to the Audi
factory rep to get them to pay for it, especially since you had documented
the problem while the car was under warranty. Be firm and insist that this
part should not fail especially under 50K miles.

Zafer
87 5KTQ IA Stage II


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