The brake caliper acts like a clamp on the wheel's rotor to stop the wheel from turning when the brakes are applied. The piston presses against the brake pads on either side of the rotor, which squeezes the rotor to slow it down. Most brake calipers consist of aluminum, a light and strong material. Sometimes magnesium alloy is used, but it is expensive and often reserved for high performance cars. The brake pads use friction to stop the rolling car and are essential for safe stopping to prevent accidents. However, this safety measure comes with a price. Friction, the process that makes the car stop, also wears down the calipers. Here are some examples of common caliper issues.
A caliper can get stuck in the closed position once it fails. When this happens, the brake shoes operated by that caliper are being constantly applied. This causes an imbalance of braking force and acceleration. Therefore, light braking becomes excessive. Normally, the vehicle pulls strongly toward the side with the stuck caliper. This problem causes the brake pads to wear easily and the rotors to be extremely hot. Too much heat can negate the friction and in the long run, the brakes won't be able to stop the car anymore. This is called brake fade.
Like what was a mentioned earlier, a stuck caliper inflicts considerable friction on the brake pads. The friction will set off a strong burning smell. This is the pungent odor of burning brake linings being seared by heat from constant contact with the brake rotor. You can feel the heat once you place the hand near the wheel with the stuck caliper immediately after driving. This is dangerous because it can set fire to volatile materials and toxic fumes will fill the cabin. The brake fluid might also come to a boil, which will make the brake pedal slide.
A stuck caliper wears the rotor unevenly, creating warp zones. These warp zones are morphed parts of the rotor that has deformities in it. Rotors are usually smooth to allow more traction when braking and flow when accelerating. When the brake pads pass over the uneven surface of the rotor, you may experience shudders or vibration. This is transmitted to the steering system and may be misdiagnosed for steering or suspension problems.
Driving with the brake always applied because of a broken caliper significantly reduces acceleration. This will make the car feel sluggish and less responsive. Consequently, fuel efficiency will suffer and mileage may decline.