Disc Brake System: Description and Operation

CONSTRUCTION
The front disc brake caliper is a pin sliding front disc brake caliper, single piston type, and attaches to the front wheel spindle with two bolts which pass through the pins.

The ends of the brake pad assemblies (2001) are contained within the spindle. The spindle abutments have anti-rattle clips (2B164) on each end to provide a low drag surface for the pads to slide against. The brake caliper mounts over the top of the pads and is bolted to the spindle on the inboard side (the outside of the caliper is secured to the outer brake pad with the outer shoe clip). The system is designed so nearly all of the brake torque generated between the front disc brake rotor and brake pads is transmitted directly to the front wheel spindle and not through the caliper housing.

A single wheel cylinder piston is located in the cylinder bore in the caliper housing, with the hydraulic fluid inlet at the bottom of the bore. A square section seal fitted into an annular groove in the caliper cylinder bore seals against hydraulic pressure, while rubber boots seal the wheel cylinder piston and caliper bore from road splash and contamination. A bleeder screw located above the cylinder bore is used to bleed air from the system.

The front disc brake hub and rotor is an integrally cast assembly. A front disc brake rotor shield, bolted to the front wheel spindle, protects the bearings and inboard surface of the front disc brake rotor from road splash. The wheel protects the outboard surface of the front disc brake hub and rotor and front disc brake caliper.