Bad MC, Sinking Pedal

[james accordino]

--- Alexander van Gerbig <Audi_80 at email.msn.com>
wrote:
>     Over the past few months I have had some brake
> pedal travel issues.

> that at stand still I
> could force the pedal to sink, never hit the floor
> though.  

> standstill.  The brakes work and I haven't had any
> failure, knocking on wood
> of course.  I haven't found any fluid leaking into
> the car at the seal.  No
> visible brake fluid loss ever

The fluid is bypassing the seals internally.  When I
examined the internals of several MC's of different
makes, the bores become worn in the area that the
seals ride most.  The wear starts at about 5% of
travel, increases to it's max at about 30% of travel
and then decreases again til about 60-70% of travel. 
That's why your brakes come back as the pedal sinks. 
It's also why merely replacing the seals, while
restoring brake function, doesn't provide an adequate
service life.  Line hone and oversize seals is a good
solution, but a stainless steel sleeve with new stock
seals is much better.  This will give a service life
longer than OEM.  Surprisingly this technology was
employed on the reman. MC I purchased at Autozone for
the SO's Dodge Shadow.  I WAS truly amazed.  Good call
on the Avant MC BTW.  It should really help with the
big brakes.

Jim Accordino