Vehicles go, but how do they stop? What components are involved in bringing a moving object to a halt? The answer lies within the aircraft braking system, specifically, brake calipers. Brake calipers play a crucial role in allowing your vehicle to stop and contribute to the overall safety of its operation. Understanding how they function can be essential in comprehending how the differing systems of your car.
Brake calipers are designed to fit over the brake rotor, with the brake pads being attached to the inside of the caliper. When the brake pedal is activated, brake fluid from the master cylinder creates hydraulic pressure that pushes the pistons in the brake caliper. The brake pads clamp down on the brake rotor to slow the car down or bring it to a complete stop. Because the rotor is attached to the wheels, they all slow down together.
There are two different types of calipers: fixed and floating. Fixed calipers are solidly mounted to a bracket, or spindle, with no sliding pins or bushings in its mount. The bracket is fastened to the rotor and typically consist of 2, 4, 6, or 8 pistons. There are an equal number of pistons on both the inboard and outboard halves of the caliper. When you apply pressure to the brakes, the pistons on both sides function in tandem and squeeze the pads against the side of the rotor. Fixed calipers provide a smoother braking feeling for the driver, which is why this type of caliper is found in performance and luxury vehicles.
Floating calipers have the ability to move. However, this movement is in and out, and is relative to the rotor. It consists of pistons on one side and slides back and forth on bushing, or pins, acting as a clamp. When the brakes are applied, the piston pushes the brake pad on the inward side against the rotor. The caliper then slides on the bushings and squeezes the outward pad against the rotor. This forces the caliper to clamp the rotor between the brake pads. Since the pistons are located on the inward side of the caliper, it provides better clearance to the wheel, as opposed to a fixed mount caliper. Floating calipers are generally cheaper in cost as they only use a single piston.
Brake calipers deteriorate over time, limiting their functionality as they age. Heat generated from the braking system inevitably wears them down which is why routine maintenance is vital. You should have your brakes checked if you experience one of the following:
You notice the car jerking to one side when braking