[urq] Brake - hard pedal when panic stopping

Maurits Jonkergouw urq at moregraphics.nl
Thu Jul 14 08:56:54 EDT 2005

I'm having exactly the same problem (and an additional soft pedal with 
ticking noise when standing still only with running engine). I changed the 
bomb but unfortunately this did not fix it. The bomb I'm using is not an 
Audi-part but a BMW 5-series aftermarket Febi Billstein P/N 01817. I do 
suspect this to be a) broken, or b) not spec'ed right like the original.

When I try the bomb test it is not possible to get a rock-hard pedal and the 
ATF container level wouldn't rise either, so I suspect the bomb is full with 
fluid but can't get it out. Because It might still be charged I'm afraid to 
switch it back with the old bomb. I'v already changed the BMC and 
proportioning valve, both OEM.

If you accelerate hard, does the pedal feel harder with even more delay? And 
if you drive normally, the pedal/brakes also feel normal?
Did you change your bomb yet? Is your pedal "hard" when the engine is 
running / standing still? What have you done to fix the problem?

PS The valve block is where the bomb is screwed/mounted in and has 2 heavy 
lines to the steering pump and brake servo.


1986 GV (Swiss WR)
1985 CGT KV
1982 GL DD

----- Original Message ----- 
From: "Ben Swann" <benswann at comcast.net>
To: <Steven.Buchholz at kla-tencor.com>
Cc: <urq at audifans.com>
Sent: Thursday, July 14, 2005 4:10 AM
Subject: RE: [urq] Brake - hard pedal when panic stopping

The pedal is hard from the get go and only goes soft after depressing the
pedal - as if there is some delay in actuating the brakes.

What do you mean by valve body - is that in the master cyl., booster,
somewhere else?


[Date: Mon, 11 Jul 2005 09:15:52 -0700
From: "Buchholz, Steven" <Steven.Buchholz at kla-tencor.com>
Subject: RE: [urq] Brake - hard pedal when panic stopping
To: <urq at audifans.com>
<BD316B4584174147B080289F69FC761602370F04 at CA1EXCLV03.adcorp.kla-tencor.com>

Content-Type: text/plain; charset="us-ascii"

... this is the classic symptom of a failing bomb ... but it could be
the valve body too.  When you shut off the engine how many brake
depressions do you get before the pedal goes hard?

Steve B
San Jose, CA (USA)]

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