Front Brake Caliper Piston, FN3

Special tools and workshop equipment 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.

Fig 1: Identifying Brake Caliper Housing

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

Fig 2: Identifying Protective Cap Pried Off From Brake Caliper With Trim Removal Wedge 3409

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-- Remove seal using 3409.

Fig 3: Identifying Removal Of Brake Caliper Seal With Wedge 3409

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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-.

Fig 4: Identifying Protective Cap And Assembly Tool T 10146/6

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-- 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.

Fig 5: Identifying Protective Cap T10146/1 & Piston Resetting Tool T10145

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Check Seating of Protective Caps

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

Fig 6: Checking Seating Of Protective Caps

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-- 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.

Fig 7: Pressing Piston Lightly Against Protective Cap And Lock It Into Position With Trim Removal Wedge

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NOTE:

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

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

Fig 8: Identifying Piston Pressed Into Brake Caliper Using Piston Resetting Tool

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