Front Brake Caliper Overhaul 25/3500 Series

Caution: Refer to Brake Dust Caution in the Preface section.

Caution: Refer to Brake Fluid Irritant Caution in the Preface section.

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.

Important: The brake calipers contain phenolic pistons that have stainless steel caps that contact the brake pad. Use compressed air to remove the piston from the caliper.

1. Remove the brake caliper. Refer to Front Brake Caliper Replacement .
2. Place a thin piece of wood in front of the piston in order to prevent damage. Remove the piston by directing compressed air into the brake hose inlet fitting port of the brake caliper.



3. Remove the piston boot.
4. Remove the piston seal.
5. Remove the caliper bleed screw cap.
6. Remove the caliper bleed screw.
7. Inspect the caliper bore and the piston seal groove for scoring and corrosion. If you find excessive scoring or corrosion around the piston seal area, replace the brake caliper.



8. Inspect the caliper bracket guide surfaces for corrosion and wear. Remove and replace the caliper bracket if necessary.
9. Clean all of the residue from the brake pad guiding surfaces on the caliper and the caliper bracket.
10. Clean all of the parts not included in the repair kit with denatured alcohol.
11. Dry all of the parts with filtered unlubricated compressed air.
12. Blow out all passages in the caliper and the caliper bleeder valve.

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.

1. Install the brake caliper bleed screw.

Tighten
Tighten the screw to 12 N·m (106 lb in).

2. Install the bleed screw cap.
3. Lubricate the new piston seals and the caliper bore seal grooves with brake fluid.
4. Install new seals into the caliper bore seal grooves.
5. Ensure that the seals are not twisted.
6. Lubricate the caliper bores and the pistons with brake fluid.
7. Install the boot and piston.

7.1.	Install the boot over the end of the piston so that the fold will face toward the brake caliper housing piston bore opening.

7.2.	Seat the boot into the brake caliper bore groove. Slide the piston into the brake caliper bore.

7.3.	Push down the piston to the bottom of the caliper bore.

7.4.	Ensure the boot seats properly into the piston groove and into the groove in the caliper bore.

7.5.	Repeat steps 5 and 6 for the remaining piston.

8. Install the brake caliper. Refer to Front Brake Caliper Replacement .