Disc Brake System: Description and Operation

OPERATION
All vehicles are equipped with front disc brake calipers (2B120). Front disc brake calipers use pin rail-type caliper assemblies with a cast iron rotor integral with the front hub assembly.

The front disc brake caliper (2B120) consists of a pin slider caliper housing, inner and outer shoe and lining assemblies, and a wheel cylinder piston (2196). The front disc brake caliper slides on two pins which also attach the front disc brake caliper to the front wheel spindle (3105).

The caliper housing contains a wheel cylinder piston. The wheel cylinder piston has a molded rubber dust boot on its outer end that is pressed into a cylinder bore groove to prevent cylinder contamination. There is also a rectangular section rubber piston seal located in the cylinder bore providing sealing between the cylinder and wheel cylinder piston. This seal also causes the wheel cylinder piston to retract once the brakes are released.

The outer brake shoe and lining assembly is longer than the inner shoe and lining assembly. The outer shoe and lining assemblies are attached to the caliper by a brake shoe hold down spring (2068) riveted to the shoe surfaces and two rectangular torque buttons on each shoe. It is important that the torque buttons are seated solidly in the matching holes in the front disc brake caliper, as well as having the brake shoe hold down spring attached to the front disc brake caliper for a properly installed outer shoe and lining assembly. The inner shoe and lining uses a replaceable brake shoe hold down spring.

NOTE: Brake rotors are constructed with straight (radial) cooling fins, and may be used on either side of the vehicle.