Why Do Brake Calipers Fail?

Brake calipers are clamp-like devices that squeeze against a wheel's brake disc to slow or stop the car. Braking efficiency will be compromised if the brake caliper begins to leak brake fluid or if the caliper's pads are excessively worn.

How Do Brake Calipers Work?

Stepping on the brake pedal puts brake fluid under pressure and pushes the fluid against pistons in the brake calipers. This force squeezes the calipers and pushes the brake pads onto the brake disc, slowing the car. This system is near-universal in all modern front braking systems and many cars also have disc brakes in the rear.

Leaking Brake Fluid

Because brake calipers have moving parts, there is the risk that friction can cause the brake lines through which the brake fluid travels to wear excessively and break. If the calipers begin to leak brake fluid, they will not build up enough pressure to force the piston in the caliper against the brake pad to stop the car. Brake calipers must be rebuilt or replaced if they show signs of leaks.

Worn Brake Pads

Brake calipers each have two pads that consist of a metal "shoe" with a lining riveted to it. If the lining on the pad wears through, the metal shoe will come into contact with the disc, or rotor, which can damage it and cause a loss of braking efficiency. A brake caliper's pads should be checked periodically for signs of wear.