What Is a Brake Pin?

The brakes of your car are very delicate and a seemingly simple procedure can have serious repercussions if part of the brake system is incorrectly adjusted or altered. The brake pin is a tiny part with an important function.

Disc brakes on a motorcycle are clearly visible. Note the clamp-like calipers.

Disc brakes work by applying friction to a brake disc attached to the wheel. The friction slows the rotation of the wheel and therefore the car. Brake pads are plates with a high friction material coating them, allowing them to grasp the disc. They are held in place by a large set of calipers that clamp the pads onto the disc when the brakes are engaged.

A set of brake calipers. The pins are in the two small cylinders on each caliper.

The calipers on disc brakes move back and forth to bring the brake pads into contact with the disc. The brake pin is what the caliper slides back and forth on. There are several on each brake, allowing even application of the brake pads to the disc. The pins must remain lubricated to ensure the caliper doesn't stick.

The brake pin must be removed to access the brake pads. A small punch and hammer can be used to tap the pin loose towards the outside edge of the car. A small spring is generally part of the pin assembly, to prevent rattling; this can come loose when the pin is adjusted.