FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Front Brake Caliper Piston, FN3






Front Brake Caliper Piston, FN3

Special tools, testers and auxiliary items required

Disassembly wedge (3409)

Piston resetting tool (T10145)

Assembly device for protective cap (T10146/6)

Removing

- Force piston from brake caliper using compressed air.

Place a wooden board into the recess of the caliper housing so it is not damaged.






- Pry off protective cap from brake caliper using (3409).






- Remove seal using (3409).






When removing, make sure that surface of cylinder is not damaged.

Installing

- The surface of the piston and seal must only be cleaned with mineral spirits and then dried.

- Thinly coat piston and seal with lithium grease (G 052 150 A2) before inserting.

- Install sealing ring in brake caliper.

- Insert the protective cap - A - into the (T10146/6) - 1 -.






- Press the protective cap with the assembly tool - 1 - and the piston resetting tool - 2 - into the brake caliper so that it contacts the brake caliper all around.






Check Seating of Protective Caps

- Protective cap must no longer be able to be pulled from brake caliper by hand.






- Press the piston lightly against the protective cap and lock it into position, e.g. with the trim removal wedge - 2 -.

- Blow the protective cap on with pressurized air (max. 3 bar) - 1 -. Protective cap springs onto piston.






Do not angle piston, to avoid damaging the seal sleeve.

- Press piston into brake caliper using piston resetting tool - 1 -.






Outer sealing lip of protective cap will then engage in piston groove.