What Is a Brake Caliper
If your car is equipped with disc brakes, brake calipers are critical to slowing and stopping your car. Here's what you need to know.
The brake caliper plays a central role in a disc-brake system and has two functions. First, it acts either as a bracket to support the brake pads on either side of the rotor or to support the caliper bracket itself — there are other designs, but these are the two most common. Second, it uses pistons to convert pressure exerted on the brake fluid by the master cylinder into friction on the rotor.
In simple terms, a brake caliper’s purpose is to squeeze the brake pads against the rotor to stop the car. There are two main types of calipers, a single piston and a dual piston. Most front calipers are dual piston but many cars use single piston calipers on the rear, where less braking force is needed.
Stepping on the brake pedal forces the master cylinder piston forward, compressing the brake fluid. The brake fluid forces the brake caliper pistons toward the rotors, pinching the rotors in between the brake pads, which creates friction and slows the vehicle.
When Brake Calipers Go Bad
In general, brake pads and rotors wear out and need replacement far more often than calipers. A leading cause for damaged calipers, however, stems from driving a vehicle on worn-out pads or warped rotors. Both prevent the system from dissipating the heat of friction, as they’re designed to do, which can damage the calipers.
If the pads fail to insulate the caliper from excessive heat, the piston can be damaged or the heat can be passed through the piston to the brake fluid, which can cause it to degrade. The latter can result in brake failure.
A damaged piston, or one that is simply corroded, may get stuck in one position. If it sticks in the retracted position, that wheel will lose braking ability. If it sticks in the engaged position, the wheel will brake continuously until freed.
- Created: 08-09-21
- Last Login: 08-09-21