Automotive Disc Brake Service (897 views)
Automotive Disc Brake Service
While brake systems vary by make and model, basically you'll find disc brakes in front, and either disk or drum brakes in the rear. A network of tubes and hoses connects your brakes to each wheel and the master cylinder, while supplying everything with hydraulic (brake) fluid.
To complicate matters, your braking equipment consists of two things: 1) hydraulics and 2) friction materials. When you press down on your brake pedal, so much happens -- more than we have space here to mention. But basically, hydraulics and friction materials work together in a kind of brake ballet to help your 2,000-pound car come to a halt, even at a high speed. Here's a simple breakdown of how your brake parts interact with each other:
1. Hydraulics -- includes the master cylinder, brake lines and hoses, and wheel cylinders and calipers.
The master cylinder converts the physical pressure exerted by your foot into hydraulic pressure. Meanwhile, brake fluid is sent to your wheel brakes via a system of brake lines and hoses. Then wheel cylinders go to work, forcing pistons out, which push the brake shoes into the brake drum. Things called "calipers" squeeze brake pads onto the "rotor" to stop your car. Both of these components apply pressure to friction materials....
2. Friction Materials -- includes the disc brake pads and drum brake shoes.
A disc brake uses brake fluid to force pressure into a caliper, where it presses against a piston. The piston then squeezes two brake pads against the rotor, forcing it to stop. Brake shoes consist of a steel shoe with a steel shoe with friction material bonded to it.
Bad braking can occur when air gets into the hydraulic fluid. The solution? Bleeder screws located at each wheel cylinder are removed to bleed the brake system. This gets rid of any unwanted air found in your braking system.
The main components of a disc brake are:
-the brake pads
-the caliper, which contains a piston
-the rotor, which is mounted to the hub
General Service Guidelines
The following general service procedures and precautions apply to all disc brake systems:
1. Work on only one wheel at a time. Failure to do so can cause the pistons to come out of the other caliper.
2. When removing a wheel, be careful not to damage the rotor, brake lines, bleeding hardware, and other components.
3. Do not attempt to remove the wheel hub with the wheel and tire mounted to the vehicle. The wheel, tire, and caliper must be removed before the hub and rotor can be removed.
4. Keep the caliper, rotor, and pad and plate assembly clean at all times. Avoid contact with grease, oil, and other fluids; wear safety glasses or goggles for eye protection.
5. Do not allow the caliper to hang by the brake hose; the hose could split as a result. Instead, hook one end of a wire coat hanger into one of the caliper bolt holes and hang the caliper on a part of the chassis.
6. Periodically check the fluid level in the master cylinder reservoirs.
7. After repairing disc brakes, check for a firm pedal action before road testing the vehicle.
NOTE: Whenever the brakes are serviced, be sure to make a thorough check for leaks in the system.