The front disc brake assembly consists of a caliper assembly, the rotor, and the lining assemblies mounted on the steering knuckle.

Applying the brake pedal causes the hydraulic pressure that moves the caliper piston. The piston then forces the inboard brake lining assembly against the inboard braking surface of the rotor. Increasing the force against the rotor causes the caliper assembly to move inboard. The outer brake lining assembly then contacts the outboard braking surface of the rotor. The force of the two lining assemblies provides the desired clamping action on the rotor.

Releasing the brake pedal relieves the pressure applied on the piston. The square cut seal on the piston relaxes and the seal allows a running clearance between the brake lining assemblies and the rotor.

The front brake caliper has a single or a dual piston. The single piston caliper is used only on RWD pickups. The dual piston caliper is used on RWD Utilities and all 4WD vehicles. Two mounting bolts hold the caliper in place. The caliper is mounted on the steering knuckle. The caliper moves laterally on the steering knuckle when the brakes are applied. The caliper is a one-piece casting with the piston bore(s) in the inboard side. A square-cut rubber seal fits in a groove in each piston bore. The square-cut rubber seal provides a hydraulic seal between the piston and the caliper bore.

The front disc brakes use a combination rotor and hub assembly. The rotor and hub are combined on RWD pickups. The rotor is separate from the hub on RWD Utilities, and all 4WD vehicles.

The rotor turns freely between the linings, until the caliper forces the linings against the rotor. The vented area between the rotor braking surfaces allows for efficient heat dissipation.

The rear brake caliper housing has a single bore. The caliper mounts to the anchor bracket with two guide pin bolts. Fluid pressure behind the caliper piston increases when applying the brakes. Pressure exerts equally against the bottom of the piston and the bottom of the piston bores. The pressure that applies to the piston transmits to the inner pad. The pressure forces the pad against the inner rotor surface. The pressure that applies to the bottom of the piston bores forces the caliper to slide on the mounting bolts. The caliper slides to the center of the vehicle. Because the caliper is one piece, the sliding movement causes the outer section of the caliper to apply pressure against the back of the outer pad. The pressure then forces the pad against the outer rotor surface. As line pressure builds, the pads press against the rotor surfaces with increased force. The force brings the vehicle to a stop. When releasing the brake pedal, the line pressure releases. The seal and the seal groove cause the piston to retract slightly. Piston retraction causes 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 fills with brake fluid from the master cylinder reservoir.

The park brake is completely independent of the hydraulic braking system. For more information on the park brake, refer to System Description in Park Brake.