Removing and installing brake caliper piston FN 3

Special tools and workshop equipment required

• Removal wedge - 3409-

• Piston resetting appliance - T 10145-

• Assembly tool for protective caps - T 10146/6-

1.4.1 Removing

• Press piston out of brake caliper using compressed air.

Place a piece of wood in the recess to prevent damage to the piston.

• Lever off protective cap from brake caliper using removal wedge - 3409-.

• Remove seal using removal wedge - 3409-.

When removing ensure that the surface of the cylinder is not damaged.

1.4.2 Installing

• The surfaces of the piston and seal must be cleaned only with methylated spirits and then dried.
• Apply thin coat of assembly paste - G 052 150 A2- to piston and sealing ring before inserting.
• Insert seal into brake caliper.

• Insert protective cap -A- into assembly tool - T10146/6- -1-.

• Press protective cap onto brake caliper so that cap is fitted correctly all round using assembly tool - T10146/6- -1- and piston resetting tool - T10145- -2-.

Check seat of protective cap:

• At this stage, it should not be possible to remove protective cap from brake caliper by hand.

• Press piston lightly onto protective cap and lock it in this position with, for example, an removal wedge - 3409- -2-.

Keep piston straight to prevent damage to sealing collar.

• Blow compressed air (max 3 bar) -1- into protective seal. The protective cap then springs onto piston.

• Press piston into brake caliper with piston resetting appliance
  • T10145- -1-.

The outer sealing lip on the protective cap will then slip into the piston groove.