Brake Caliper Inspection Overview
Brake caliper assemblies must be kept in good condition to ensure safety. Careful maintenance is therefore essential. The rubber parts of caliper assemblies are especially critical with regard to safety since they act as fluid seals, protect the calipers from the entry of dirt and other foreign substances, and return the pistons to their original positions when the brakes are released. Thus, rubber parts must be fitted with particular care.
The disassembly and reassembly procedures for the front and rear brakes are different owing to the incorporation of the parking brake mechanism into the rear brakes (except vehicles with parking drum brake). However, operations performed in these procedures are basically the same.
Rapid reinstallation of front brake pistons requires special skill. After reading this article, practice the operation until you can perform it properly. With rear brakes, special tools are required for caliper disassembly and reassembly. You must learn how to use these special tools correctly.
Brake Caliper Inspection Disassembly
- Cam boot Replace.
- Spring washer
- Parking nut
- Return Spring
- Lever
- 8 mm flange bolt
- Bleed screw
- Pin
- Sleeve piston
- Adjusting bolt
- Bearing A
- Spacer
- Adjusting spring B
- Circlip
- Piston boot Replace.
- Piston
- Piston seal Replace.
- Spring cover
- Cup Replace.
- O-ring Replace.
- Caliper body
- Arm
- Cam
- Retainer
- Pad spring
- Pin
- Pin boots Replace.
- Caliper bracket
- Caliper bracket mounting bolts
- Caliper mounting bolts
- Brake pads
- Outer pad shim
- Use recommended silicone and pin greases in the caliper seal set.
- Use recommended rubber grease in the caliper seal set.
Never use compressed air or a dry brush to clean brake assemblies. Use a vacuum cleaner to avoid scattering and breathing brake dust.
CAUTION:
- • Before performing disassembly, remove the brake fluid in the reservoir using a syringe.
- • When disconnecting a brake line from a caliper, use a container to catch the brake fluid.
- • After disconnecting a brake line, cover its open end with a plastic bag to prevent the entry of foreign substances.
Precautions for Disassembly
- Store disassembled parts safely to avoid losing them.
- If the brake pads are reused, each one must be reinstalled in its original position. Make a position mark on each pad to ensure correct reinstallation.
- Before removing a piston from a caliper using compressed air, clamp the caliper securely in a vise.
- When using a Brake Spring Compressor, first ensure that the tool is properly engaged. Then, turn the handle slowly, taking care not to trap your fingers.
Brake Caliper Reassembly
- Inner shim B
- Wear indicator Install inner pad with its wear indicator upward.
- Pin boots Replace.
- Caliper bracket
- Pad retainers
- Outer pad shim
- Piston boot Replace.
- Piston
- Piston seal Replace.
- Caliper body
- Caliper bolt (pin A)
- Bleed screw
- Caliper bolt (pin B)
- Brake pads
- Inner shim A
Quick, accurate insertion of a piston into a front caliper body with a piston seal and boot is a skill that must be acquired through practice.
Precautions for Brake Caliper Reassembly
- Clean all parts carefully before reassembling them.
- Take steps to prevent dust and other foreign substances from entering the brake hydraulic system.
- Replace all rubber parts with new ones.
- Two types of grease are used on brake assemblies. Do not confuse their application points.
- Apply grease thinly and evenly. Excessive grease application may cause the brake system to malfunction.
- After installing a piston seal, feed its surface with your finger. If you feel any points that are not seated properly, install the seal again.
- When using a Brake Spring Compressor, first ensure that the tool is properly engaged. Then, turn the handle slowly, taking care not to trap your fingers.
CAUTION:
When reassembly is complete, fill the brake system with new brake fluid and check that the service brakes and parking brake function properly.