Replacing Master Cylinder 5KCSTQ

[Kneale Brownson]

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At 08:11 AM 02/19/2002 -0800, Erik Gerrits wrote:

>I watched as someone pumped the brakes on my car
>(while running) and I could see a drip of brake fluid
>come out of back of the master cylinder (where it
>bolts on).  Two questions, should I replace the master
>cylinder?  And if so is there anything special that I
>need to know?  I don't have the Bentley book,
>unemployed at the moment.

How do you know it was brake fluid, Erik?  There's a drain hole in the
bottom of the spot where the MC bolts to the brake booster that, I presume,
is intended to allow condensation to drip out.  One of my Audis on which I
changed the MC had a big collection of rust plugging that hole.  I can
picture moisture dripping out of such a situation when the rod connecting
the booster with the MC moved.  The fluid also could be hydraulic oil from
the booster system, although I'd much rather change a MC than a booster.

If it IS brake fluid, there's a rubber seal at the back of the MC housing
around the actuator rod that probably is leaking.  That shouldn't cause
problems with braking as long as you keep the brake fluid level up.  But it
may be indicative of additional deterioration in the MC assembly.
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