A SUMMARY OF HOW DISC BRAKES WORK
When you press on the brake pedal, the master cylinder pumps hydraulic brake
fluid through the system under high pressure. The fluid courses through the steel
line infrastructure to the brake calipers. The pressure of the fluid pushes on the
back of the pistons that are within the calipers. This forces the pistons outward,
causing the calipers to clamp down on rotors (discs). The friction caused by the
brake pads (which are attached to the calipers) when they come in contact with
the rotors causes the vehicle to stop.