The rotor is a highly machined cast iron, ventilated type.
The caliper is a single bore, floating piston type. When the brake pedal is pressed, the fluid pressure behind the caliper piston increases. Pressure exerts equally at the following locations:
• | Against the bottom of the piston. |
• | Against the bottom of the piston bore. |
The pressure that is applied to the piston transmits to the inboard brake pad, forcing the pad against the inside of the rotor surface. The pressure applied to the bottom of the piston bore forces the caliper to slide on the mounting bolts toward the center of the vehicle. This movement causes the outer section of the caliper to apply pressure against the back of the outboard brake surface. As the pressure builds, the pads are pressed against the rotor with increased force, bringing the vehicle to a stop.
When the brake pedal is released, the fluid pressure releases. The piston and the pads retract from the rotor slightly, lessening the pad to rotor drag. This allows the wheel to turn again. The piston rubber seal keeps the clearance at a minimum at all times. When hydraulic pressure releases from the piston, a restoring force generates at the seal and pushes back the piston in order to prevent brake drag.
The following actions automatically compensate for pad wear:
• | Outward movement of the piston |
• | Inward movement of the caliper |
As the pads wear down, the increased area behind the piston is filled with brake fluid from the master cylinder reservoir.
The caliper mounts to a caliper carrier by sliding pins. The caliper carrier bolts to the steering knuckle.