Front Disc Brakes

Front Disc Brake Components:

Front Disc Brake Caliper Assembly (Exploded View):

Overview
The single piston, floating caliper front disc brake system consists of the following components:
- Front disc brake caliper.
- Brake shoes and linings.
- Rotor.
- Disc brake caliper adapter.
- Hub/Bearing.
These components are described in detail below.

Disc Brake Caliper.
The single piston, double pin floating disc brake caliper is a one piece caliper made of cast iron. The inboard side of the caliper has a single bore containing a 60 mm (2.36 inch) phenolic piston. The brake caliper is mounted to the caliper adapter using guide pin bolts.

Brake Shoes.
The brake shoe lining material is an organic non-asbestos formula. The brake lining material used has been specifically formulated to meet the braking requirements of the vehicle. When brake shoes are replaced, only brake shoes meeting the original equipment manufacturer formulation (such as Mopar replacement parts) should be used. This will maintain the original braking performance of this vehicle.

Rotor.
The purpose of the rotor is to slow down and stop the front wheels of the vehicle. This is accomplished by applying the brake shoes against the braking surfaces of the rotor. The rotor is made of iron and is vented to help cool it during brake applications.

Disc Brake Caliper Adapter.
The caliper adapter is used to mount the disc brake caliper to the steering knuckle. The caliper adapter has machined abutments on the top and bottom to control the for and aft movement of the caliper during brake applications. The caliper adapter also reacts against the braking forces when stopping the vehicle.

Hub/Bearing.
The hub/bearing is used to mount the front brake rotor and wheel. The rotor is mounted to the front face of the hub by the wheel mounting studs and retained by the wheel mounting nuts. The hub/bearing is mounted to the steering knuckle using four mounting bolts.

Disc Brake Caliper Mounting To Adapter:

The double pin front disc brake caliper is mounted to the caliper adapter, using bushings, sleeves, and caliper guide pin bolts. The caliper guide pin bolts thread into the caliper adapter. The adapter for the front disc brake caliper is mounted to the front of the steering knuckle. The adapter is mounted to the steering knuckle using the hub/bearing mounting bolts.
The two machined abutments on the caliper adapter, position and align the caliper fore and aft. The guide pin bolts, sleeves, and bushings control the side to side movement of the caliper. The piston seal is designed to assist in maintaining the proper brake shoe to rotor clearance.
All the forces generated by the front brakes, when stopping the vehicle, are taken up directly by the caliper adapters and the steering knuckles.
The caliper is a one piece casting with the inboard side containing a single piston.
The phenolic piston is 60 mm (2.36 inch) in diameter.

Fig. 2 Piston Seal Function:

A square cut rubber piston seal is located in a machined groove in the cylinder bore. It provides a hydraulic seal between the piston and the cylinder wall.
The molded rubber dust boot mounts in a counter bore of the cylinder bore opening and in a groove which is machined in the outer surface of the piston. This prevents contamination of the piston and the bore area.
As lining wears, reservoir level will go down. If fluid has been added, reservoir overflow may occur when the piston is pushed back into the new lining position. Overflowing can be avoided by removing a small amount of fluid from the master cylinder reservoir.