Brake System Components

The brake system of an automobile or other vehicle is the system responsible for halting the wheels to bring the vehicle to a stop. These are not typically very complicated systems, but they do have a lot of parts that are vital to the effective operation of the entire system. There are three primary types of brake systems: disc brakes, drum brakes and air brakes.

Disc Brakes

Disc brake systems stop the rotation of a car's wheels by pressing a brake pad against a brake disc, or rotor. Disc brake systems typically employ a master cylinder filled with brake fluid. When the brake pedal is pressed the brake fluid is forced through brake lines, which causes a system of brake calipers on the wheels to press the ceramic or carbon brake pads against the metal rotor.

Drum Brakes

Drum brake systems are similar to disc brakes in that they are a means of physically stopping car tires from turning. Instead of discs or rotors, drum brake systems have a round, hollow drum affixed to the tire. When the brake pedal is pressed brake fluid is forced out of a master cylinder through a brake line to the brake shoes on the tire, forcing them outward and against the interior wall of the brake drum. Drum brake systems also have a backing plate that holds the braking assembly together and return springs that force the brake shoes back into their starting positions once the brake is released.

Air Brakes

Air brake systems are similar to the above-listed hydraulic systems, except that, instead of brake fluid, air is used to pressurize the brake pads against the wheels. Air brakes are somewhat more complicated than their fluid-based counterparts. They use air storage tanks, an air compressor that pumps air into the storage tanks, an air compressor governor that controls the air compressor, air tank drains that help remove moisture from the air storage tanks, an alcohol evaporator that injects alcohol gas into the air system to prevent ice in the supply lines, various gauges of the air pressure within the system, and the typical system of drums or discs, depending on the exact types of brakes the air brake system is using.