Brakes are a system of parts working together. Knowing what each part does makes it easier to understand a repair estimate — and to order the right replacement.
Disc brake parts
Most vehicles today use disc brakes on the front wheels, and many use them on the rear as well.
- Brake pads press against the rotor to slow the wheel. They are a wear item and are replaced in sets across an axle.
- Rotors (also called discs) are the metal discs the pads clamp onto. They can wear thin, warp, or develop grooves, and are commonly replaced in pairs.
- Calipers hold the pads and use hydraulic pressure to squeeze them against the rotor. They can stick or leak over time.
- Caliper brackets mount the caliper to the vehicle.
- Hardware kits include clips, shims, and pins that keep pads positioned and quiet.
Drum brake parts
Some vehicles, especially older models and some trucks, use drum brakes on the rear.
- Brake shoes press outward against the inside of the drum.
- Drums are the round housings the shoes press against.
- Wheel cylinders push the shoes outward using hydraulic pressure.
- Springs and hardware return and position the shoes.
Hydraulic parts
- Master cylinder converts pedal pressure into hydraulic pressure.
- Brake booster multiplies the force from your foot.
- Brake lines and hoses carry brake fluid to each wheel.
ABS and electronic parts
- Wheel speed sensors tell the anti-lock brake system how fast each wheel is turning.
- ABS modules control anti-lock braking and, on many vehicles, stability control.
- Electronic parking brake components are used on many newer vehicles.
Common warning signs
Have a qualified technician inspect your brakes if you notice:
- Squealing or grinding noises
- Vibration or pulsation in the pedal or steering wheel when braking
- The vehicle pulling to one side under braking
- A soft or spongy pedal
- A brake or ABS warning light
These signs can have several causes, so a proper inspection is the best way to know which parts actually need replacing.
What to know before ordering brake parts
- Front or rear: Front and rear brake parts are almost always different.
- Brake package: Many vehicles offer standard, heavy-duty, towing, or performance brakes. The rotor diameter and caliper type differ.
- Trim and VIN: These help confirm which brake package your vehicle has.
- Parking brake type: Electronic parking brakes may affect rear caliper selection.
Safety first
Brakes are safety-critical. We recommend that brake parts be installed and inspected by a qualified technician.
Need brake parts?
Call Rock Sales Parts at +1 646 244-2586 with your vehicle details and tell us which axle you are working on. We can help source pads, rotors, calipers, and other brake parts. See our brake parts page for more.
Need help finding this part?
Call with your vehicle details — we will help identify the right part and let you know what we can find.