Need Hydraulic Pressure Accumulator for Coupe Q

[Ben Swann]

I believe I had/have a blockage in the screen going into the check valve.  Indications
were that the pump was going south, I swapped out with known good used pump and had some
improvement.   Got a lot of crappy fluid out - had metal like particles in suspension.
 
I now have some assist with engine running.   Still the brake light goes on with hard
braking and assist not 100% but OK for now.
 
Pedal now goes hard after shutoff, so  looks like the bomb is depleted too.  
 
I think the problem will clear after bomb is replaced and new fluid run through the
system.
 
Ben

  _____  

From: Tony Hoffman [mailto:auditony at gmail.com] 
Sent: Wednesday, January 19, 2011 8:50 PM
To: hah at alumni.rice.edu
Cc: Ben Swann; quattro at audifans.com; 20v at audifans.com; 200q20v at audifans.com
Subject: Re: Need Hydraulic Pressure Accumulator for Coupe Q


That sounds like servo/pump/blocked line failure to me as well. My V8Q had a dead bomb
(one pump after shutdown, hard pedal) yet always had perfect pedal while running. If I
pumped the pedal a couple of times in quick succession I could get a hard pedal also,
but it would then go back to normal after a second or so of running. The bomb should
only be for after shutdown, if it's hard while running there are definately other
problems.
Tony


On Wed, Jan 19, 2011 at 12:57 PM, Henry A Harper III <hah at alumni.rice.edu> wrote:



This sounds more like a brake servo failure (servo check valve?) to me. Even
with a dead bomb which my 200q20v had for several years until I got around
to replacing it, there is (or should be) enough pressure from the pump alone
to supply assistance in normal easy braking - I would have to stomp the
pedal hard to get the brake warning light to come on with the car running.
Not that you don't also have a dead bomb, but what you describe were not my
dead-bomb symptoms; when I replaced the bomb all was well with no brake
warning light and many pedal stomps.

Henry Harper