In a caliper-type disc brake, what is the caliper's function?

In a caliper-type disc brake, what is the caliper's function?

• A. Applies lubrication to the rotor.
• B. Holds the rotor in place.
• C. Squeezes pads against a disc or rotor to create friction.
• D. Releases brake fluid pressure.

Answer: (C)

The caliper’s job is to press the brake pads against the spinning rotor to create friction that slows or stops the wheel. When you apply the brakes, hydraulic fluid pushes pistons inside the caliper, and those pistons squeeze the pads onto the rotor from one or both sides, converting the wheel’s kinetic energy into heat. This function is distinct from lubrication or rotor mounting—the rotor is attached to the wheel hub, and lubrication is for bearings and guide pins, not the friction surfaces. Releasing brake pressure is done by other parts of the system, not by the caliper itself. So the essential role of the caliper is to clamp the pads against the disc to generate the stopping friction.

The caliper’s job is to press the brake pads against the spinning rotor to create friction that slows or stops the wheel. When you apply the brakes, hydraulic fluid pushes pistons inside the caliper, and those pistons squeeze the pads onto the rotor from one or both sides, converting the wheel’s kinetic energy into heat. This function is distinct from lubrication or rotor mounting—the rotor is attached to the wheel hub, and lubrication is for bearings and guide pins, not the friction surfaces. Releasing brake pressure is done by other parts of the system, not by the caliper itself. So the essential role of the caliper is to clamp the pads against the disc to generate the stopping friction.