ALT-2 How Disc Brakes Work
To get started we need to know all the parts that help apply disc brakes whether it is front or rear. First the brake pedal, then the brake booster, master cylinder, brake line, brake hose, caliper, brake pads and last the rotor. You can also have parking brake cable if your vehicle has rear disc brakes on some models.
When you apply force to the brake pedal you push a rod that goes through the brake booster which is most likely a vacuum booster unless you own a mid-90's full size Chevy van. In the vacuum brake booster there is a vacuum that is on the outside. It creates a pressure difference between the pedal side that you are pushing on and the side that the master cylinder is on. This pressure difference allows you to apply more pressure to the master cylinder. This booster was put on for the very reason of using disc brakes cause of the added pressure needed to apply them.
After the boost of pressure from the booster you will push on the plunger of the master cylinder which will push fluid with a metal cylinder and a rubber seal. It will push the brake fluid through the metal brake lines to the brake hose. The brake hoses purpose is to allow movement of the suspension.
It will then go to the caliper. Now the cylinders in the master cylinder is about a 1/4 the size of the caliper piston. This allows you to multiply pressure again by using hydraulics. This caliper then pushes on the brake pad. When the pressure reaches a point after the inner pad touches the rotor. The caliper which rides on pins slides until the outer pad then reaches the rotor. This will then slow the car down cause of the rotor is attached to the car. After you release the brake pedal the caliper that has a square seal around the piston nows pulls back on the piston enough to move the pad away from the rotor just enough to make sure the pads aren't touching the rotor to prevent premature brake pad wear.
That is how the disc brakes work and now you can stop safely.
