Rear Brake Caliper, Servicing

Rear brake caliper, servicing

Note:
- When repairing install all parts supplied in repair kit.
- New brake calipers are filled with brake fluid and pre-bled.
- Apply thin coat of assembly lubricant G 052 150 A2 to brake cylinders, pistons and seals.
- When carrying out repairs it is essential to prebleed the brake calipers (without brake pads) before installing in the vehicle

1. Self-locking hex bolt, 35 Nm (26 ft. lbs.)
- Always replace
- When loosening and tightening counterhold on guide pin
2. Bleed valve
- Apply thin coat of assembly lubricant G 052 150 A2 to threads before installing
3. Dust cap
4. Guide pins
- Grease before pulling on protective cap
5. Protective cap
- Pull onto brake carrier and guide pin
6. Brake carrier with guide pin and protective cap
- Replacement part is assembled with sufficient grease on guide pins
- If protective caps or guide pins are damaged, install repair kit. Use grease packet supplied to lubricate the guide pins.
7. Protective seal
- Pull outer sealing lip onto piston
8. Piston with automatic adjustment
- Removing and installing
- Apply thin coat of assembly lubricant G 052 150 A2 to piston before inserting
9. Sealing ring
- Removing and installing
10. Brake caliper housing with parking brake cable lever
- If a leak exists at the parking brake cable lever replace brake caliper housing
- After repairing, pre-bleed caliper housing

Rear brake caliper piston, removing and installing

Special tools and equipment





- 3272 Piston resetting and removal tool





- 3409 Wedge
- Bleeder container

Removing





- Remove piston out of brake caliper housing by turning the knurled wheel counter-clockwise.

Note:
^ Use special tool 3272/1 to help screwing in.
^ If piston is difficult to move, use a 13 mm (0.512 inch) AF open end wrench on the flats (arrow -A-) provided for this purpose.





- Remove seal using wedge 3409.

Installing
- The surface of the piston and seal must only be cleaned with methylated spirits and then dried.
- Apply a thin coat of assembly lubricant G 052 150 A2 to piston and seal before inserting.





- Place protective seal with the outer sealing lip on the piston.





- Using wedge 3409, insert the inner sealing lip into the grove in the cylinder.

Note: Hold piston in front of caliper housing.





- Screw piston into housing by turning knurled wheel clockwise.

Note:
^ Use special tool 3272/1 to help screwing in.
^ If the piston is pushed back with a piston resetting tool or by operating the foot brake the automatic adjustment in the brake caliper is destroyed.

- Install brake pads.

Pre-bleeding brake caliper





- Open bleed valve -arrow A- and using a standard bleeder bottle, with brake fluid until bubble-free brake fluid flows from the threaded hole -arrow B- (brake hose connection).
- Close bleed valve.

Note: Position brake caliper as illustrated to pre-bleed.