Front Disc Brakes

DESCRIPTION - FRONT DISC BRAKES
The front disc brake assembly used on this vehicle consists of the following components:
- Disc brake caliper
- Brake Shoes (pads/linings)
- Caliper abutment rail shims
- Brake Rotor








The floating double pin single piston calipers used on this vehicle are mounted directly to the steering knuckles and use no adapter. The caliper is mounted to the steering knuckle using bushings, sleeves and two thru-bolts which thread directly into the steering knuckle.
The caliper is a one piece casting with the inboard side containing a single piston cylinder bore. The front disc brake caliper phenolic piston is 60 mm (2.36 inch) in diameter.
There are two brake shoes (pads) mounted to the brake caliper. One brake shoe mounts on each side of a brake rotor. The brake shoe lining material used has been specifically formulated to meet the braking requirements of the vehicle. An audible wear indicator is mounted on the outboard brake shoe.
Rail shims are mounted above and below the brake pads (when installed) on the machined caliper abutment rails of the knuckle.
The brake rotor is mounted on the hub and bearing. The rotor is made of iron and is vented to help cool it during brake applications.





Vehicles equipped with standard four-wheel-disc brakes utilize a conventional internally-vented hat style rotor. Internally-vented refers to the fact that the inner most diameter of the braking disc vents to the rear of the rotor.
Vehicles equipped with performance four-wheel disc brakes utilize an inverted-hat style rotor. This rotor is externally vented meaning the inner most diameter of the braking disc vents to the front (or face) of the rotor.
Although there are two different style brake rotors depending on brake packages, they are serviced in the same manner.

OPERATION - FRONT DISC BRAKES
Two machined abutments on the steering knuckle position and align the caliper fore-and-aft. The guide pin bolts, sleeves, and bushings control the side-to-side movement of the caliper.
Although there are different disc brake systems available, they operate and are serviced in the same manner.





A square-cut rubber piston seal is located in a machined groove in the cylinder bore. This provides a hydraulic seal between the piston and the cylinder wall. The piston seal is designed to pull the piston back into the bore of the caliper when the brake pedal is released. This, along with the brake shoe retractor clips, maintains the proper brake shoe to rotor clearance.
A molded rubber dust boot is installed in a groove in the cylinder bore and the piston, keeping contamination from the cylinder wall and the piston.
The brake shoe lining material rides against the brake rotors braking surface. When the brakes are applied, the shoes apply pressure against the rotor, thus slowing the vehicle.
As brake shoe linings wear, master cylinder reservoir brake fluid level will go down. If brake fluid has been added to the reservoir, overflow may occur if the piston is pushed back into the recessed position.
An audible wear indicator is mounted on the outboard pad of the front disc brake assemblies. Upon contact with the brake rotor, this indicator emits a sound, signaling that brake shoes may need inspection or replacement.