Don---I recall my pistons being fairly easy to move in and out, using
stiff finger pressure, even with the new seals. (I didn't use the red
lube, only brake fluid here). You are correct in that hydraulic pressure
would move (tight) pistons out, and brakes would drag when the pedal is
released. So...this can't be what want. The o-ring seal on the piston
should squirm from pressure from behind. Sort of like a tire going thru
slip angle. When pressure is released, the piston is pulled back into
the bore a few thousandths, from the o-ring resuming its natural state.
The run-out of the brake rotor is not enough to push the pads back, if
the piston won't move easily.
In short, your brakes will drag if left the way you describe.
Be sure there is no pockets of air causing the pistons to resist moving
back into the bore.
Dick
Don wrote:
How tight should the new calipers be in the cylinders. Mine are very
tight. Almost can't even turn them in the cylinders. I bead blasted the
cylinder cavity so I know the rubber seal groove was very clean. Hmmm I
put some of that red brake lube in the groove. Maybe that was a mistake.
I'll clean it out. I just had to remove one because I put it together
w/o the dust boot. It was harder to get this new one apart than it was
the old rusty ones.
Anyway should I be able to insert and withdraw the pistons easily -- by
hand w/o tools or do they fit tighter than that? How tight is too tight?
I guess I don't have a feel for how powerful the hydraulic system is.
Even if the hydraulics are strong enough to push the piston out, what
causes the brake pads to pull away from the rotors when the brake pedal
is released? These pistons are so tight, I would imagine they would drag
on the rotors.
Thanks,
Don Malling
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