Disc Brake System: Description and Operation
DESCRIPTIONThe disc brake assembly consists of a caliper assembly, rotor, and pads mounted to the steering knuckle. The caliper mounts in a way that allows it to, move laterally against the rotor. The caliper is a one piece casting with the inboard side containing the piston bore. A square cut rubber seal fits in a groove in the piston bore, to provide a hydraulic seal and return mechanism for the piston.
OPERATION
Applying the brake pedal causes hydraulic pressure to move the piston. The piston then forces the inboard brake pad against the inboard braking surface of the rotor. Increasing the force against the rotor causes the caliper assembly to move inboard. The outer brake pad then contacts the outboard braking surface of the rotor. The force of the two brake pads provides the desired clamping action on the rotor.
Relieving Pressure
Releasing the brake pedal relieves the pressure applied to the piston. The square cut seal on the piston returns to its normal position, allowing a running clearance between the brake pads and rotor.
SERVICING INFORMATION
^ Replace all components included in the repair kits.
^ Lubricate the parts as specified.
^ Do not use lubricated shop air on brake parts. Rubber component damage may result.
^ After any hydraulic component has been removed or disconnected, if necessary, bleed all or part of the brake system. Service and Repair
^ Replace brake pads in axle sets only.
^ The torques specified are for dry, unlubricated fasteners.
^ Perform service operations on a clean bench free from mineral oil and any other contaminants.
^ Use extreme care when doing any work around the antilock components to prevent damage or misalignment.
^ Before moving the vehicle, pump the brake pedal several times to make sure it is firm. Do not move the vehicle until a firm pedal has been obtained. Check the brake fluid level in the master cylinder after pumping the brakes.