Your Trusted Auto Repair Shop for 40+ Years
Shop Talk Logo

Understanding Brake Components

Keeping your car running properly means more than taking it in for regular maintenance and having the brakes checked. To understand everything that your technician tells you, you must have a basic understanding of how your car works. The brakes, in particular, are fairly complex – but as soon as you familiarize yourself with the basic components, it will be easier to understand what your brake specialist tells you during maintenance or repair appointments.

Rotors and Pads

Brake rotors are mounted to every wheel on your car. These are steel discs and hubs that the brake pads sit on top of and grip the surface. The pads are metal backing pads containing semi-metallic overlays. These two components work together to make your wheels stop rotating when you press on the brake pedal, causing the pads to stop the rotor.


Brake calipers are a big component of your vehicle’s hydraulic brake system. They are the housing that sits over the brake rotor holding the brake pads. When the brakes are applied, the hydraulic piston housed in the caliper extends and squeezes the brake pads together against the brake rotor which slows or stops the vehicle.

Master Cylinder and Brake Lines

The master cylinder in your car is responsible for creating hydraulic pressure from the reservoir to the brake caliper at the wheel. The brake lines are hoses made of braided steel or rubber that are found throughout the vehicle and connect the master cylinder and each individual brake caliper.

Wear Indicator

As the name implies, your brake wear indicator helps to let you know when your brake pads need to be replaced. Many modern wear indicators will contain some sort of sensor or metal body that contacts the rotor and leads to a warning light appearing on your dashboard. When this light appears, you should replace the brake pads or visit your local brake specialist at Sun Auto Service.

Proportioning Valve

The proportioning valve is typically located close to the brake master cylinder. It helps to distribute the proper hydraulic pressure to the front and rear brakes, respectively. Since the front of the vehicle is heavier, carrying the weight of the engine requires approximately 60% of the available hydraulic pressure, while the remaining 40% is applied to the rear.

ABS Module

The ABS module, also known as the ABS control module, reads speed data sent by your ABS speed sensors. It then uses this information to send each wheel the ideal amount of pressure, reducing the risk of sliding and skidding by helping the brakes from locking up the wheels.