Caliper Overhaul

Rear Caliper Assembly:

48H Rear Caliper Assembly - Cutaway View:

1. Remove nut (9), parking brake lever (10) and lever seal (12).
2. Inspect bracket (25) and bridge (26) for cracks or distortion.

NOTE: Caliper can be overhauled without removing bridge (26).

3. Remove bridge bolts (24), bracket (25) and bridge (26), only if suspected of being cracked or damaged.

NOTE: Use clean shop cloths as a pad over bridge (26)
and under caliper housing (27) during piston removal.

Removing Caliper Piston:

4. Remove piston assembly (14) by rotating actuator screw (18) in parking brake apply direction to work piston from caliper bore.
5. Inspect the piston assembly (14) for scoring, nicks, corrosion and worn or damaged chrome plating. Replace piston assembly if any of the above are found.
6. Remove actuator screw (18) by pressing on thread end.
7. Inspect actuator screw (18) for cracks and thread damage.
8. Remove balance spring (19).
9. Remove shaft seal (21) and thrust washer (20) from actuator screw (18).

Removing Caliper Boot:

10. Pry dust boot (16) from caliper taking care not to damage caliper bore (27).

NOTE: Do not use a metal tool to remove piston seal. Metal tools may damage caliper bore or seal groove.

11. Using a small piece of wood or plastic, remove piston seal (17) from piston seal groove (39) in caliper housing (27).
12. Inspect bore and piston seal groove (39) for scoring, nicks, corrosion and wear. Use crocus cloth to polish away corrosion from housing bore. Replace caliper housing (27) if corrosion in and around piston seal groove (39) will not clean up with crocus cloth.
13. Remove bleeder valve cap (22) and bleeder valve (23) from caliper housing (27).
14. Clean all parts in clean. denatured alcohol. Dry with unlubricated compressed air. Blow out all passages in caliper housing (27) and bleeder valve (23).

ASSEMBLE
1. Reinstall caliper bridge (26), if removed during disassembly. Then install bleeder valve. Torque bridge bolts (24) to 100 Nm (74 lb. ft.) and bleeder valve to 13 Nm (116 lb. in.)
2. Install lubricated piston seal (17), piston, caliper bore and dust boot.
3. Roll piston seal into seal groove in caliper bore, ensuring seal is fully seated and not twisted.
4. Install thrust washer (20) on actuator screw (18), with copper side of washer facing toward piston assembly, then install shaft seal onto actuator screw.
5. Install lubricated shaft seal (21) on actuator screw (18).

Installing Boot To Piston Assembly:

6. Install lubricated boot (16) onto piston assembly (14).

7. Install lubricated actuator screw (18) and balance spring (19) into caliper bore. Ensure end of spring fully bottoms in recess at bottom of bore.

NOTE: Make sure outside diameter of piston assembly (14) is well lubricated before installation.

Seating Boot To Caliper Housing:

8. Install piston and boot assembly, push piston into bore, then turn actuator screw as necessary until piston fully bottoms in caliper.
9. Install lever seal over end of actuator screw, ensuring rubber sealing bead is against lever and copper colored side is against caliper housing.
10. Install parking brake lever over actuator screw, rotate lever away from stop, then hold lever and torque retaining nut to 47 Nm (35 lbs. ft.). After tightening retaining nut, rotate lever back to stop.
11. Seat dust boot in caliper counterbore using suitable driver.