RE: 200 rear caliper problem

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

... well, I assume that the 200 rear brakes work like those I am familiar
with on the qtc ...

It turns out that the rear brake caliper has two pistons in an open
cylinder, one piston is used to compress the pads on the rotor and the other
one at the "back" of the caliper activates the e-brake.  There is a
mechanical threaded connection that allows the e-brake to work if the
integrity of the hydraulic system is compromised.  This is why you must
rotate the piston as you push it back into the caliper ... you are threading
the automatic adjusting safety mechanism back in.  

Given that this is the way your brakes work I must admit that I'm at a bit
of a loss as to why a failure of the e-brake actuation mechanism would cause
a mushy brake feeling.  As long as the rear piston is firmly in place there
should be no difference in behavior.  I suppose if it was possible that the
rear piston was not in it's rest position and it was possible for the
braking pressure to force the rear piston to move back slightly that could
be it ...

HTH!
Steve Buchholz
San Jose, CA (USA)

	----------
	However the driver's rear caliper is still sticking, even after WD40
	and forced operation of the cam.  The good news is that the e-brake
	lever, which once could be raised to the upper limit, now has less
than
	two inches of travel, and I don't appear to have a rusted emergency
	brake.

	I searched the qlist archives but could not find any tips on dealing

	with this problem, and bentley does not appear to go into any detail
	in rebuiding the rear calipers on this issue, only covering piston
and
	seal replacement.

	Could someone explain how the emergency brake closes the caliper, so
	that
	I have a better understanding of what is causing the binding, an
whether
	the caliper can be rebuilt or whether I should spring for a rebuilt
	one...