Modern passenger vehicles are almost always equipped with disc brakes on at least the front two wheels, and many manufacturers are using them on all four wheels. The primary components of the disc brakes are:
Rotor
Caliper
Brake pads FIGURE 32-3
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FIGURE 32-3
The disc brake system.
The rotors are the main rotating part of this brake system. They are durable and resist being damaged by the high temperatures that occur during braking. In high-performance vehicles, the rotors are made from composite materials, ceramics, or carbon fiber; otherwise, they are usually made of cast iron.
The caliper straddles the rotor and houses the disc brake pads and an activating piston(s). The calipers use hydraulic pressure from the master cylinder to apply the brake pads. They are usually bolted to the steering knuckle or, in the case of a nonsteering axle, to a suspension component. Calipers need to be inspected at the same time as the brake pads.
The disc brake pads are located inside the caliper or caliper mounting bracket. The pads clamp onto the rotor to slow or stop the vehicle. The disc brake pad consists of a friction material bonded or riveted to a steel backing plate. With this design, the pads will wear out over time and need to be replaced periodically.
