Overhaul

BRAKE CALIPER

DISASSEMBLY





1. Drain the brake fluid from the caliper.
2. Take a piece of wood and pad it with a one-inch thickness of shop towels. Place this piece (1) on the outboard side of the caliper (2) in front of the piston.





WARNING: NEVER ATTEMPT TO CATCH THE PISTON AS IT LEAVES THE BORE THIS COULD RESULT IN PERSONAL INJURY.

WARNING: DO NOT BLOW THE PISTON OUT OF THE BORE WITH SUSTAINED AIR PRESSURE. THIS COULD RESULT IN A CRACKED PISTON.

3. Remove the caliper piston (2) by using short bursts of low pressure air with a blow gun (1) through the brake hose port. Use only enough air pressure to ease the caliper piston out.





4. Remove the piston dust boot (2) with a suitable pry tool (1) and discard.

CAUTION: DO NOT SCRATCH PISTON BORE WHILE REMOVING THE SEALS.

5. Remove piston seal (2) from the caliper with a suitable tool (1).
6. Remove the caliper bleed screw.
7. Clean the caliper.

CLEANING

CAUTION: DO NOT use gasoline, kerosene, paint thinner, or similar solvents. These products may leave a residue that could damage the piston and seal.

Clean the caliper components with clean brake fluid or Brake Clean only. Wipe the caliper and piston dry with lint free towels or use low pressure compressed air.

INSPECTION

CAUTION: If the caliper piston is replaced, install the same type of piston in the caliper. Never interchange phenolic resin and steel caliper pistons. The pistons, seals, seal grooves, caliper bore and piston tolerances are different.

Remove deposits on the piston using a soft brass wire brush or a rough shop towel. Do not clean piston with a polishing or emery cloth because this will damage the chrome-plated surface. Replace the piston if the chrome-plated surface is damaged.
Clean anodized aluminum versions (piston and housing bore) with a soft rag only.

If the piston is jammed or if the cylinder bores are scored or rusted, replace the complete fixed brake caliper and with the floating brake caliper, replace the cylinder housing. Remove small, light rust spots in the cylinder bore with a polishing cloth. Remove heavy rust spots in front of the groove for the piston seal using fine-grained emery paper (grain size 380 to 500).

ASSEMBLY





CAUTION: Dirt, oil, and solvents can damage caliper seals. Be sure the assembly area is clean and dry.

1. Lubricate the caliper piston, piston seals, and piston bore with clean brake fluid.

NOTE: Verify seal is fully seated into seal groove and not twisted.

2. Install the new piston seal (2) into the seal groove.
3. Install the new dust boot (4) on the caliper piston (3) and seat the dust boot lip into the piston groove.
4. Stretch the dust boot (4) rearward to straighten the boot folds, then move the boot forward until the fold snaps into place.
5. Install the piston (3) into the caliper bore and press the piston down to the bottom of the caliper bore by hand or with the handle of a hammer.
6. Seat the dust boot (4) in caliper (1).
7. Install the new caliper bleed screw.
8. Install the caliper.