Brake Caliper Slide Pins
Metal pins that allow a floating brake caliper to slide back and forth, centering itself over the rotor.
Brake caliper slide pins, also known as guide pins, are metal bolts that secure a floating brake caliper to its mounting bracket. Floating calipers are the most common design on modern vehicles, utilizing a single piston that pushes on one side. The slide pins allow the caliper body to slide back and forth sideways.
As the piston pushes the inner pad against the rotor, the caliper slides on the pins to pull the outer pad against the opposite side of the rotor, applying equal pressure. The slide pins are greased and protected by rubber boots.
If the boots tear and water enters, or if the grease dries out, the slide pins will rust and seize. A seized slide pin prevents the caliper from sliding, leading to uneven brake pad wear, brake dragging, pulling to one side under braking, and reduced stopping power. Cleaning and lubricating these pins is a vital part of any brake job.