[s-cars] Hard brake pedal - but the light is off. thoughts?

[Aaron Ryba]

Jamie,

I have been dealing with the same situation. I recently replaced my hydro pump and restored power to the steering rack but my brakes pedal was still stiff. That raised the pressure enough to turn off the brake light while driving but it would come on when doing a three pint turn or just after startup before proper pressure could accumulate. Trying to diagnose this problem I also found the pedal to be rock hard after about 2 pumps with the car off and also no fluid comes out of the servo when disconnected. Sometimes I feel pulsating in the brake pedal which is tied to engine rpm/hydro pressure.

When replacing the bomb this weekend I found some small particles in the integrated filter screen in the bolt at the bomb. Most likely from the previous shredded pump running itself down. Not sure if the used bomb I put in is any better that what was taken out, perhaps my slightly better pressure and completely off light are due to the cleaning of this filter?

Also, my brake pedal will sometimes stick momentarily when depressed, causing jerky braking. I can't help but feel this is an issue with the oh so expensive to replace servo. Or perhaps the it is only the integrated screen filters at the ends of my slightly leaking J-hose that doesn't provide enough pressure?

Aaron Ryba
95 S6 140k

-----------------------------------------------------------------------
Message: 5
Date: Sun, 1 Jul 2007 20:33:13 -0700 (PDT)
From: james McCarthy <jjssmccarthy at yahoo.com>
Subject: [s-cars] Hard brake pedal - but the light is off.  thoughts?
To: s-car-list at audifans.com
Message-ID: <913672.72235.qm at web52605.mail.re2.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1

Folks,

Returned to the s6 after a week away.  
Very hard pedal feel. Softens slightly after running
for 10 seconds or so The "brake" light behaves
normally - on for start up and off after 15 seconds or
so.  

When I stab the brakes the light flashes briefly -
this doesn't occur when I press it lightly.

So bomb?  The pedal becomes rock hard with just two
strokes in the bomb test.
But it's only 2 yrs old and if it is the bomb why
isn't the light on all the time and shouldn't I have
relativly normal braking when the car has been running
for several minutes?

The servo?
I disconnected the return line on the servo - no fluid
come out.
When I started it some fluid came out of the servo -
but how much is too much?

Pump is about 16 months old...

I'm tempted to do the bomb and a flush.

thoughts?
tia
-jamie




       
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