Your car's disc braking system contains brake calipers, which play a vital role in getting your car to stop. The brake calipers also house other parts of your vehicle - the pads and pistons. Brake calipers work alongside your brake rotors to create friction that brings the car to a stop. Brake fluid is generated when you press down on the brake pedal, creating pressure on the pistons inside. This pushes your brake pads against the rotors to stop the car. If your calipers wear out, you should get them replaced.