Brake Systems

When it comes to the individual components of your braking system, it depends on whether your vehicle has four-wheel disc brakes, four-wheel drum brakes or a combination of the two. Regardless, here is a brief breakdown of each brake system component.

Master Cylinder and Power Brake Booster:

The master cylinder is a hydraulic pump that is actuated by the brake pedal. Attached to the pump is a brake fluid reservoir and vacuum-assisted power booster to make it easier to press the pedal.

Rotor:

A brake Rotor is a heavy metal disc attached to the wheel (actually, to the wheel hub). It spins as the wheel and tire spins. Brake rotors will wear out eventually because of all of the friction applied to them. They also are susceptible to overheating if you tend to have aggressive driving habits or haul heavy loads.

Brake Pads:

Brake pads are made to grab hold of a brake rotor. The sacrificial friction material on the pads comes in contact with the rotor when you brake, producing friction and heat used for the transfer of kinetic energy to thermal energy. Brake pad materials come in a variety of compositions, from organic to ceramic to semi-metallic compounds. Each type of brake pad has its advantages and disadvantages.

Brake Shoes:

Like brake pads, brake shoes create friction to stop your vehicle. But shoes are more likely to be found on cars from decades past or on trucks. Picture a bowl spinning on a potter’s wheel or a lazy susan. If you were to reach into the bowl and move your hands apart and press against the inside of the bowl, you would create resistance. That is basically what brake shoes do inside a brake drum.

Brake Drum:

Where a rotor is grabbed from the outside by the brake pads, a brake drum is grabbed from within by a pair of brake shoes.

Caliper & Caliper Braket:

A brake caliper is a hydraulic clamp that squeezes the brake pads against the rotor in response to the force applied by your brake pedal through the master cylinder pump. The caliper bracket holds the caliper in place and suspends the brake pads on either side of the rotor.

Wheel Cylinder:

There is no caliper in a drum brake setup. Instead, a hydraulic device called a wheel cylinder presses the brake shoes apart and against the inside of the drum.

In addition to these brake system components, there are other minor parts: hardware clips, shims, guides, pins, and the like. These components might be small and seem insignificant, but a missing clip or corroded pin can keep your brakes from working properly – or at all.