Rear Brakes

Brake Caliper Piston

Special tools, testers and auxiliary items required

• Trim removal wedge (3409)

• Resetting and extracting tool (T10165)

Removing

- Remove piston from brake caliper housing by turning knurled wheel counterclockwise.





• Insert resetting and extracting tool (T10165) - 1 - so that collar - arrow - is in front of piston.

• For pistons that are difficult to move, an open-end wrench (size 13 mm) can be applied at the appropriate wrench surface - arrow A -.

- Remove seal using trim removal wedge (3409).





Installing

- Use only appropriate solvent to clean surfaces of piston and protective seal, then dry.

- Apply thin coat of assembly paste (G 052 150 A2 ) to piston and protective seal before installing.

- Install sealing ring in brake caliper housing.

- Place protective seal with outer sealing lip on piston.





- Using trim removal wedge (3409 ), insert inner sealing lip into cylinder groove.





• Hold piston in front of caliper housing for this procedure.

- Screw in piston by turning knurled wheel clockwise.





• Insert resetting and extracting tool (T10165) - 1 - so that collar - arrow - on tool makes contact at brake caliper.

• For pistons that are difficult to move, an open-end wrench (size 13 mm) can be applied at the appropriate wrench surface - arrow A -.

• When piston is mis-adjusted with a piston resetting tool or if foot brake is operated, the automatic adjustment in the brake caliper will be destroyed.

- Insert brake pads.

Brake Caliper, Pre-Bleeding

- Open bleeder valve - arrow A - and fill with brake fluid using standard bleeder bottle until brake fluid flows out of threaded hole (end of brake hose) - arrow B - without bubbles. Close bleeder valve.





• Position brake caliper as shown during pre-bleed procedure.