How Does a Car Brake Work?

Understanding how car brakes work is important in helping you detect problems or potential problems with your car's braking system. The braking system is vital to your safety and your ability to react in a dangerous situation. The two types of brake systems are disc and drum. Though they look different, but they work in similar ways to stop your car.

The Disc Brake Assembly

The disc brake assembly at each wheel consists of a caliper with a fluid-filled piston, brake pads, the brake line that holds the brake fluid and feeds the fluid to the caliper and the rotor. There are other components away from the assembly, such as the master cylinder, which converts energy from one type to another when you press the brake pedal. You must remove the wheel to access the brake assembly.

 The Stopping Action Explained

When your foot touches the brake pedal, the fluid-filled piston pushes on the brake pads. The brake pads, of which there are two, are forced inwardly against the rotor by the action of the piston. As the brake pads make contact with the rotor on each side of it, this creates friction. That friction is what slows and stops the wheel from turning. If you have drum brakes, there is a metal circle that the brake shoes are pushed against outwardly.

 Anti-Lock Brakes

If you have anti-lock brakes, you would also see a round metal disk that is hollow. It is called the "ABS Exciter Ring." This metal disk is approximately four inches across and has teeth all the way around. Its purpose is to force the brakes to grab at quick intervals, thereby preventing them from locking if you jam the brakes.