Disc Brake - Front

DESCRIPTION - DISC BRAKES (FRONT)








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

Fig. 2 Piston Seal Function:

The single-piston, double-pin floating disc brake caliper is a one-piece unit made of cast iron. The inboard side of the caliper has a single bore containing a 60-mm (2.36-inch) phenolic piston. A square cut rubber piston seal is located in a machined groove in the caliper's cylinder bore. A 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. The brake caliper is mounted to the caliper adapter using guide pin bolts.
The brake shoe lining material is an organic non-asbestos formula. The brake lining material 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.
The rotor is made of iron. It is vented to help cool it during brake applications.
The disc brake caliper adapter has machined abutments on the top and bottom.





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 using the hub and bearing mounting bolts.

OPERATION - DISC BRAKES (FRONT)
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 single-piston, double-pin floating disc brake caliper operates in the following manner. As hydraulic pressure is applied to the rear of the piston in the caliper, the piston moves outward applying the inboard brake shoe. At the same time the inboard shoe begins to apply against the brake rotor, the force causes the caliper to move inward, sliding on the guide pin bolts and sleeves. This action applies the outboard brake shoe. When hydraulic pressure is released, the caliper returns to its original position.
The square cut rubber piston seal provides a hydraulic seal between the piston and the cylinder wall. The piston seal is designed to pull the piston back into the cylinder bore in the caliper when the brakes are released. This action also helps maintain proper brake shoe-to-rotor clearance.
The molded rubber dust boot prevents contamination of the piston and the bore area of the brake caliper.
The brake rotor slows down and stops the front wheels of the vehicle. This is accomplished by applying the brake shoes against the braking surfaces of the rotor.
The caliper adapter is used to mount the disc brake caliper to the steering knuckle.
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.
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 adapter machined abutments control the fore-and-aft movement of the caliper during brake applications. The caliper adapter also reacts against the braking forces when stopping the vehicle.