What are Brake Calipers?
Brake calipers hold the brake pads. They are hydraulic actuators that transfer force from application of the brake pedal to the friction material (brake pads) via hydraulic fluid contained in lines that interconnect the brake pedal assembly and the calipers. Calipers may be used on the front or rear brakes and are mounted to the spindle assembly over the brake rotors.
There are two main types of calipers: floating calipers that move in and out relative to the rotor and have one or two pistons only on the inboard side of the rotor, and fixed calipers that don’t move but have pistons arranged on opposing sides of the rotor.