Caliper Overhaul

Fig. 2 Rear disc brake caliper exploded view. Eldorado, Firebird, Riviera, Seville, Toronado & 1982---86 Camaro:

Fig. 3 Removing piston from bore:

DISASSEMBLY
1. Clamp caliper in a vise and remove the two mounting sleeves and four bushings, Fig. 2.
2. Remove brake shoes and lever return spring.
3. Rotate parking brake lever back and forth to remove piston from housing, Fig. 3. If piston will not move from housing, remove locknut, lever and anti-friction washer. With a 9/16 inch wrench, rotate screw clockwise on right hand caliper or counterclockwise on lefthand caliper until the piston moves from housing. Pad caliper with shop cloths when removing piston.
4. Remove piston assembly and balance spring.
5. Remove lock nut, lever, lever seal and anti-friction washer if not removed previously.
6. Push screw from housing, then remove piston seal and boot.

Fig. 4 Positioning piston in caliper:

Fig. 5 Installing piston into caliper:

Fig. 6 Driving boot into caliper:

ASSEMBLY
1. Install new piston seal.
2. Install new boot onto piston assembly with lip of boot located in piston groove.
3. Install new thrust washer and seal on actuator screw.
4. Install actuator screw into piston assembly. The piston assemblies are identified by a stamped letter on the adjuster nut end. ``L'' denote lefthand and ``R'' denotes righthand. The caliper housing is also marked with a letter. The parking brake will not function if the caliper and actuator screw are located on the wrong side of vehicle.
5. Coat piston seal with clean brake fluid. Install balance spring into piston and install assembly into caliper housing, Fig. 4.
6. With tool J-23072, push piston fully into caliper housing, Fig. 5. The piston must be pushed straight into caliper to prevent damage to the actuator screw seal as it passes through hole in rear of piston bore.
7. Before removing tool J-23072, install lubricated anti-friction washer, new lever seal, lever and locknut. Position lever away from stop, rotate forward and hold lever in position, then torque nut to 25 ft. lbs.
8. Remove tool J-23072, rotate lever back to stop and install return spring. On Cadillac the return springs are color coded red for righthand and black for lefthand.
9. With tool J-26296, drive boot until seal bottoms in caliper housing, Fig. 6.