Disc Brake System: Description and Operation

Fig 1 Disc Brake Components:

GENERAL INFORMATION
This vehicle is equipped with single piston, slider type disc brake calipers. The calipers slide laterally on pins that attach the caliper to the steering knuckle.

The brake shoes ride on ledges machined in the steering knuckle. The shoe mounting ears are notched to seat on these ledges. The notched ears also maintain fore and aft position of the shoes. A retainer spring on each brake shoe maintains shoe position in the caliper.

The single piston used in each caliper is non-metallic. The pistons are made of a phenolic resin material.

Ventilated, disc brake rotors are used for all applications. The rotors are serviceable and can be machined to restore the surface finish when necessary.

The calipers are fully serviceable components and overhauled when necessary.

CAUTION: The brake shoes are replaceable components but must be replaced on both front wheels at the same time to maintain braking balance. Never replace the shoes on only one side.

Fig 1 Disc Brake Components:

BRAKE LINING WEAR COMPENSATION
The caliper piston seal controls the amount of piston extension needed to compensate for normal lining wear.

In operation, the seal is deflected outward under fluid pressure. When fluid pressure is released, the seal relaxes and retracts the piston. The amount of retraction is determined by lining wear. Generally, the amount is just enough to maintain contact between the piston and inboard shoe and a zero or very slight clearance at the rotor.

The fluid level in the front brake reservoir will decrease as lining wear occurs. This is a normal condition and only requires adding enough fluid to restore proper level.