How They WorkBrake pads are the part of the braking system that actually bring your car to a stop. Pads are located on the insides of each rotor. When you press the brake pedal, the brake pads squeeze the vehicle's brake rotors—the flat, shiny discs that you can sometimes see just behind the wheel. That pressure placed on the brake rotors is what slows the wheel, eventually bringing it to a stop. Though the role of brake pads is pretty simple, the brake pads are a critical part of the brake system.
Common RepairsBecause they're under near-constant stress, brake pads need to be monitored for signs that they need repair. Here are a few of the most common brake pad repairs.
Thinning Brake pads have an embedded stip, called a shim; when your brakes wear so thin that the shim is compressed, the shim creates a squeaking noise alerting the driver that the shim is worn. Once the brake pads hit this threshold, it's time to see your mechanic for brake service.
“Metal-to-Metal” “Metal-to-metal” describes brake pads or shoes that have worn through all of their friction material. This means that the metal backing of the pad or shoe rubs on the rotor or drum, which is also made of metal.
Breakage A moving car has a lot of kinetic energy, which is energy in motion; to bring your car to a stop, your brakes use friction, which converts that kinetic energy into heat. Sometimes the combination of heat, stress, and wear can cause the pads to break, like the photo above.
Signs and SymptomsUsually, when your brake pads need replacing, you’ll hear it first. There will be a noticeable, low-pitched, grinding sound when braking, often accompanied by a vibration in the steering wheel while stopping. You may also notice:
- that your stopping distance increases
- that you have less control when turning
- that you have to apply an immense amount of pressure on the brake pedal to bring the car to a complete stop