Re: Matador Brake Questions

[Tom Jennings <tomj@xxxxxxx>]

On Mon, 23 May 2005, Todd Tomason wrote:

> When the local tire shop fixed a flat yesterday they said the brake caliper
> seemed to be grabbing.  My first thought was to just replace the caliper, but
> now I'm not so sure.  We checked both front wheels when got home and both
> seem very stiff.  You had to grab the tire with both hand to get it to move
> at all.  Could this be a bad master cylinder instead?  Is there anything else
> I should be checking?  BTW, this is a 78 with front discs and rear drums.

Lessee...

Assuming the master cylinder was replaced "recently", were the
check valves removed from the brake line port before installation?
Drum brakes need 'em; most master cyls ship with them; you remove
them for disk brakes.  THey keep a bit of pressure on the brake
shoes to "take up the slack".  Makes disk brakes drag.

Could also be the calipers are tight in their brackets; or that
the flat, curved spring behind the wedge that holds the calipers
onto the bracket is installed on the wrong side (causing them to
be tight).  When you take you foot off the brake, the piston in
the caliper retracts a few thousandths of an inch; normal runout
of the rotor causes the shoes and calipers to "center" and just
barely scuff.  Press the piston into the caliper a bit (1/8" to
1/4"), assemble the caliper, you should be able to slide the
caliper side to side without *too* much effort. Might require a
tap with a rubber mallet or your palm, or might slide easily.
Shouldn't rattle around or require lots of force. Clean burrs with
a file, wirebrush caliper and bracket, get a new wedge and spring
(NAPA #82432 from my notes, but napaonline can't find sh*t) and
grease it lightly.

Could be stuck pistons in crapped up calipers, caused by age
or not frequent enough bleeding/fluid changing.