Brake Caliper Overhaul Without B9Q/V4U

Tools Required

J 35777 Caliper Piston Seal Installer

1. Remove the caliper from vehicle. Refer to Brake Caliper Replacement .

Caution: Do not place your fingers in front of the piston in order to catch or protect the piston while applying compressed air. This could result in serious injury.

2. Remove the piston by directing low pressure compressed air into the caliper inlet hole.




Important: Care must be used when removing the piston boot and seal from the caliper. Use a small plastic or wood tool for removal. Do not use a metal tool because it may damage the caliper bore or seal groove.

3. Remove the piston boot from the caliper.
4. Remove the piston seal from the caliper.
5. Remove the bleeder valve and cap from the caliper.
6. Clean all of the parts. Use clean, denatured alcohol. Dry all of the parts with non-lubricated, low pressure compressed air. Blow out all of the passages in the caliper body and the bleeder valve.
7. Inspect all of the parts as follows.

•	Piston - Inspect for scoring, nicks, cracks, wear, or corrosion. Replace the piston if any damage is found.

•	Caliper Bore - Inspect for scoring, nicks, cracks, wear, or corrosion. Use crocus cloth to polish out light corrosion. Otherwise, replace the caliper. Do not hone the caliper bore.

•	Seal groove in the caliper bore for nicks or burrs. If found, replace the caliper.

8. Install the bleeder valve cap and bleeder valve into the caliper.
9. Install the new piston seal. Lubricate the seal with clean brake fluid before installing.



10. Install the new piston dust boot seal over the piston.
11. Using theJ 35777 fully seat the boot in the caliper.
12. Install the caliper onto the vehicle. Refer to Brake Caliper Replacement .

Brake Caliper Overhaul With B9Q/V4U

Tools Required

J 36474 75 mm Boot Seal Installer

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
2. Remove the tire and wheel assembly.
3. Remove the fluid from the caliper (1).
4. Remove the brake pad. Clean the interior of the caliper with clean shop towels.

Caution: Do not place your fingers in front of the piston in order to catch or protect the piston while applying compressed air. This could result in serious injury.

Notice: Use just enough air pressure to ease the piston out of the bore. You can damage a blown-out piston even with the padding.




5. Remove the piston.

•	Direct compressed air into the caliper fluid inlet.

•	Use just enough air pressure to ease the piston out of the bore.




6. Remove the boot using care not to scratch the housing bore.



7. Remove the piston seal with a nonmetal type of tool.



8. Remove the bleeder valve.
9. Use denatured alcohol in order to clean the following parts:

•	The bleeder valve

•	The caliper bore

•	The caliper passages

•	The piston

•	Use dry, filtered, compressed air to dry the parts and to blow out the passages.

10. Replace any piston with the following conditions:

•

Scoring

•

Nicked

•

Corroded

•

Worn

•	Damaged chrome plating

11. Replace any caliper bore or seal groove with the following conditions:

•

Scoring

•

Nicked

•

Corroded

•

Worn

•	Attempt to remove any light corrosion on the caliper bore or seal groove using a crocus cloth.

1. Use clean brake fluid in order to lubricate the following parts:

•	The new piston seal

•	The caliper bore

•	The piston




2. Install the piston seal using care not to twist the seal.



3. Install the boot on the piston.



4. Install the piston and the boot into the caliper bore.
5. Push the piston to the bottom of the bore.



6. Seat the boot housing usingJ 36474 orJ 36475 or J 38453 .



7. Install the bleeder valve.

Tighten
Tighten the bleeder valve to 13 N·m (115 lb in).

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

8. Install the tire and wheel assembly.
9. Lower the vehicle.