disc brakes do not use residual pressure check valves. only drum brake set
ups use residual pressure check valves. and in reference to that , the
check valve was intended to keep wheel cylinder cups spread slightly to keep
them sealed against the cylinder walls/ bore. if you have spreaders(a
spring loaded disc pressing against the rear<fluid side> of the rubber cup)
in your wheel cylinder there is no need for a check valve there either.
some feel the check valve will give a higher pedal, or a faster aplication
of a brake. this may be so! but that was not the original design of the
check valve. without the check valve , brake fluid would seep past a wheel
cylinder seal when sitting stationary for extended periods, since a wheel
cylinder cup is not intended to be a tight interference fit.
in disc brake set ups, if you use a residual pressure check valve the pads
will not properly release all the way and you will constantly have the pads
dragging on the rotors. this will cause premature pad wear and rotor
warpage. the pads will actually be in a partially applied situation any
time you are not on the pedal.
chuck.
----- Original Message -----
From <Andrew.Griffith at ReadRite.com>
To: <spridgets@autox.team.net>
Sent: Tuesday, August 01, 2000 3:32 PM
Subject: Residual pressure valve of front disk brakes.
> Anyone ever use a residual pressure valve on the front disk brakes? If so
> what pressure did you go with? For those who haven't heard of one of these
> before... They're a pressure valve that keeps a couple to a few pounds of
> peddle or brake pressure in the line (normally the front) to maximize and
> quicken your braking... or at least that's how I understand they work.
> Thanks a heap,
> -Drew in San Jose
>
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