Disc Brake System: Description and Operation

Front Caliper:

APPLYING PEDAL PRESSURE
When the brakes are applied, fluid pressure behind the caliper piston increases. Pressure is exerted equally against the bottom of the piston and also against the bottom of the piston bore. The pressure applied to the piston is transmitted to the inner pad, forcing the pad against the inner rotor surface. The pressure applied to the bottom of the piston bore forces the caliper to slide on the mounting bolts toward the center of the vehicle. Since the caliper is one piece, this movement causes the outer section of the caliper to apply pressure against the back of the outer pad, forcing the pad against the outer rotor surface. As line pressure builds, the pads are pressed against the rotor surfaces with increased force, bringing the vehicle to a stop.

RELEASING PEDAL PRESSURE
When the brake pedal is released, line pressure is released and the seal and seal groove cause the piston to retract slightly, resulting in less drag on the rotor by both pads. Outward movement of the piston and inward movement of the caliper automatically compensate for pad wear. As the pads wear, the increased area behind the piston is filled with brake fluid from the master cylinder reservoir.

CAUTION:
- Do not use lubricated compressed air on brake parts as damage to rubber components may result.
- If any hydraulic component is removed or disconnected, it will be necessary to bleed all of the brake system. Service and Repair
- Perform service operations on a clean bench, free from all mineral oil materials.

NOTE:
- Replace all components included in repair kits used to service this caliper.
- Lubricate rubber parts with clean brake fluid to ease assembly.
- The tightening specifications are for dry unlubricated fasteners.
- Replace brake pads in axle sets only.