553 Brake Systems Technician Handbook Brake Systems Basic brake systems use: • A reservoir to store fluid until it is needed • A master cylinder to create pressure • Brake tubing to transfer the pressure to the wheels • Disc brakes, that apply pressure to a rotor to generate the friction needed to stop the vehicle. Almost all vehicles use disc brakes on the front wheels. Some use disc brakes on all four wheels. • Drum brakes, that apply pressure to a rotating drum to generate friction. Drum brakes are often used on the rear wheels of larger vehicles such as truck and SUVs. Other components can include:
• A vacuum brake booster that uses engine vacuum to increase brake pressure during emergency stops • A hydraulic brake booster that uses a pump and accumulator to increase brake pressure during emergency stops • A proportioning valve, the shift more brake force to the front wheels during heavy braking • An Electronic Control Unit (ECU) that uses a computer to control braking and improve vehicle stability 6 Technical Training