RE: master cylinder question

[Aleksander Mierzwa <alex@matrix.com.pl>]

Ken wrote:

	>1.  What does a failing master cylinder act like?  What are the
	>symptoms?
	>
	>I pulled the brake (vacuum) booster off my 4ksq and put it on
my C-GT 
	>to see if it would make the pedal 'softer', but it's the same.
I think 
	>it'll only get worse.

	>(My brake pedal is very hard, and basically feels 'unassisted'
at all.)

When the MC fails, the pedal travel increases and/or pedal goes to the
floor occasionally (BTDT, not on an Audi though). Sometimes faulty MC
seizes and causes brakes to bind. If the pedal travel is correct and
your problem is lack of assist, I wouldn't suspect the MC (not the first
thing to check, in any case). Sorry for asking such a silly question,
but did you perform the standard brake servo test? I mean, press the
brake pedal - start the engine - look if the pedal falls. I understand
you proved it's not the servo itself, but maybe you have a huge vacuum
leak somewhere (especially in the vacuum hose going to the servo?)

	>3.  And, as if those weren't enough, I think maybe my timing
belt is too
	>tight 
	>or something is going out.  There's a brand new water pump on
it, and
	>there 
	>is a loose, sloppy, dare-I-say very loaded bearing sound coming
from the 
	>front of the motor at idle.  It's not the BZZZZ-BZZZZ or
VVVVV-VVVV of
	>the 
	>timing belt teeth making noise because it's too tight.  It's a
loose, 
	>rattly kind of sound.  Does anyone know what the heck I'm
trying to
	>describe?

I'm not sure if you have a separate t-belt idler pulley on the CGT, if
yes - this can be the source of the noise.

Aleksander Mierzwa
Warsaw, Poland
mailto:alex@matrix.com.pl
87 Audi 5000CS turbo (mine)
88 Renault Medallion wagon (mom's)
91 mountain bike (just in case both cars broke at the same time :-)