Disc Brakes - Front

DISC BRAKES - FRONT

When the brakes are applied, fluid pressure is sent to each brake caliper. The pressure at the caliper is exerted equally against the caliper piston. The pressure applied to the piston is transmitted directly to the inboard brake shoe. This forces the shoe lining against the inner surface of the brake rotor. At the same time, fluid pressure within the caliper piston bore forces the caliper to slide inward on its guide pins. This action brings the outboard shoe lining into contact with the outer surface of the brake rotor. This pressure on both sides of the brake rotor causes friction, bringing the vehicle to a stop.


When the brake pedal is released, so is the fluid pressure. The piston seal inside the caliper is designed to pull the piston back into the bore of the caliper when the brake pedal is released (Figure 1). This action helps maintain the proper brake shoe-to-rotor clearance.


As disc brake shoe linings wear, master cylinder reservoir brake fluid level will drop. Adjust as necessary. Fluid level should always be checked after replacing shoes.





Figure 1 Caliper Piston Seal Function For Automatic Adjustment