334 Auto Brakes
Figure 19-6. An integral brake drum and rotor assembly. A—Rotor and drum has been removed to show the parking brake shoes.
B—Disc brake rotor illustrating the parking brake section. (Chrysler)
Disc brake
adapter
Braking disc
stone shield
Parking brake
brake shoes
A B
Shoe return
spring
Hub/bearing
assembly
Hat section of
rear braking disc
(parking brake
braking surface)
Rear
braking
rotor
Parking brake
actuating strut
Figure 19-7. Using a screwdriver to turn the star wheel, set-
ting the correct shoe-to-drum operating clearance. Be sure to
replace the adjuster hole plug. (FMC, ATE)
Caliper
Disc
Drum
Screwdriver
Shoe
Drum
Star
wheel
Adjuster
hole
Note: In some cases, this is easier to
perform using a box-end wrench.
Disc Brakes
Three common parking brakes are used with rear-
wheel disc brakes. They are the screw, ball-and-ramp, and
cam. Service procedures for each type are discussed in
Chapter 13. You may need to adjust the rear caliper pistons
to the rotors after brake service and occasionally after long
periods of parking brake disuse. In some cases, the brake
pedal only needs to be pumped several times to bring the
pads in adjustment. However, a special adjustment proce-
dure is sometimes needed to bring the pads into position
and to obtain a good pedal.
Using a flat-head screwdriver, carefully position the
tip against the top lip of the caliper piston, Figure 19-8.
Clamp a pair of vice grips on the caliper’s parking brake
actuating mechanism.
While carefully prying against the piston, use the
vice grips to apply and release the parking brake. The
caliper piston should adjust the pads until they just rest
against the rotor. If the caliper piston fails to move, try
tapping the caliper piston area with a ball-peen hammer.
Be careful not to damage the bleed screw. If the piston
continues to stick, remove the caliper and perform an
overhaul.