[s-cars] brake problem...need advice

[Jack Gagnon]

Chris,

The sputtering you feel is the hydraulic pump trying to provide pressure
after the system has lost pressure. You must have a leak somewhere that is
causing the pressure to leak down when sitting.

 I have had similar problems, but not as bad as you describe.  Last winter,
the light finally stayed on and would not go out and there was now power
assist at all.  In my case I replaced the bomb and all was well for a while.
I think my problem I had was a sticking check valve in the bomb.  The
weather was extremely cold at the time and I suspect I may have had some
moisture in the hydraulic system that froze and caused the problem.  I may
have been able to fix the problem without replacement of the bomb, but the
car has over 200k and a new bomb isn't a bad thing.  The light stayed off
for about a month and now it is coming back on for a short time after
sitting for more than 4-5 hours.

I have heard that the brake assist servo at the master cylinder can leak
fluid back into the system and cause low pressure upon start up.  This can
be tested by allowing the bomb to build pressure and disconnecting the low
pressure side of the servo at the master cylinder if fluid is dripping, the
servo is leaking.  Be careful to only open the low pressure side!

I recently had another type of hydraulic fluid problem.  There was hydraulic
fluid leaking badly from the master cylinder area.  It was dripping bad
enough to leave nice rainbow spots every 2 feet on my driveway and disabled
the car due to low fluid.  Fortunately this happened at my house.  I was
happy to find that the fluid was leaking from the pressure sensor and a 1/4
turn of the switch fixed the problem.

The system only has so many components and tracking it down may take time,
but I am sure you will be able to find the problem.

Jack

-----Original Message-----
From: s-car-list-bounces at audifans.com
[mailto:s-car-list-bounces at audifans.com]On Behalf Of chris chambers
Sent: Friday, June 17, 2005 10:53 PM
To: Vincent Fregeac; Scar
Subject: Re: RE : [s-cars] brake problem...need advice




--- Vincent Fregeac <vfregeac at sympatico.ca> wrote:

> Thinking about it, two new ideas:
> - Brake light also goes on when the fluid level is low. Check your
> fluid
> level and the fluid level detector. Mine was sticky on the 90Q20V
> with light
> going on when on bumpy roads.

FLuid level is fine, light only comes on when I first start the car,
then it goes away.


> - If the light goes on when your car is idling but goes of when you
> drive
> it, it may be a sign of hydraulic pump agony, BTDT too on the 90Q20V,
> amongst so many other BTDT :(

The light is not on when idling, only when first starting the car, even
if after only letting it sit a few minutes. The thing that really gets
me is the "stuttering" I feel in the brake pedal if I don't wait a
couple minutes after starting the car.


Thanks
Chris



AUDI - Accelerates Under Demonic Influence.



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