Pedal The driver of a vehicle steps on the brake pedal to stop the vehicle. The pressing of the pedal moves a piston located in the master cylinder. Master Cylinder The master cylinder is located directly in front of the driver's seat on the firewall in the engine. A master cylinder typically houses two separate master cylinders. Each master cylinder handles a set of wheels. The master cylinder controls the hydraulic pressure of the hydraulic fluids. The hydraulic tubing lines connect the master cylinder to the brake cylinders. When the pedal is pressed, two internal pistons move and a valve opens in the master cylinder. The hydraulic fluid must pass through the valve, a chamber and a series of tubes and hoses to get to the brake cylinders. Brake Booster Mounted on the firewall behind the master cylinder in a power braking system is the brake booster. The booster is a shell divided by a rubber diaphragm into two chambers. Stepping on the brake closes a valve in the diaphragm and opens another valve, allowing air into the chamber on the pedal side. By using an intake stroke of the engine to create this vacuum, the booster amplifies the applied foot pressure so that the amount of pressure needed to stop is minimal. Drum Brakes Drum brakes are located on the rear wheels. When the brakes are applied, the pressurized fluid forces its way into the wheel cylinder of the drum brakes. This pushes the brake shoes into contact with the inside of the brake drum and slows down the vehicle. A pushrod transfers motion from one shoe to the other. Disc Brakes Most vehicles have disc brakes only on the front wheels, though newer vehicles may have disc brakes on all four wheels. With disc brakes, the fluid from the master cylinder forces into a caliper where it presses against a piston. The piston squeezes two brake pads on a disc rotor attached to the wheel. This forces the wheel to slow down and stop. Emergency Brake The emergency or parking brake is a fully mechanical system that controls the rear brakes. Steel cables connect the parking brake to either a hand lever or a foot pedal and bypass the hydraulic system. Brake hoses Brake hoses create a flexible connection between brake pipes and wheel brakes. They transmit the hydraulic pressure to the wheel cylinders and brake callipers. Brake hoses are usually made form a special inner and outer rubber with a multi-layer fabric insert in between Brake pads Brake pads are a key brake part because they are the component that contacts and applies pressure and friction to a vehicle's brake rotors Brake shoe A brake shoe is the part of a braking system which carries the brake lining in the drum brakes used on automobiles Adjuster mechanism Is used to calibrate the brake shoe for the emergency brake mechanism Return spring Is used to return the brake shoe to the start position to avoid the Contact all the time Caliper mounting bolt Is to mount the caliper on the base for a floating caliper Piston Do press the brake pad to the rotor Noise shim Avoid the noise of the piston with the brake pad Retainer Avoid that the piston goes out from the caliper Dust boot Avoid filtration of dust to the piston part and brake fluid Brake fluid reservoir It contains the fluid to the system
