How a Brake Booster Works

The brake booster is located at the back of the engine compartment on the driver’s side of the car. When the hood is opened it seen as the round, black canister, they are found as drum brakes or disc brakes. Old car models use drum brakes while newer vehicles run on disc brakes.

Vehicles that have disc brakes on front wheels use power brakes which make it easy to operate them. When pressure if applied on the master cylinder, the brake booster uses vacuum from the engine to multiply the force.

Importance of Brake Booster

The brake booster is part of the braking system in a motor vehicle. This is one of the most important functions of the vehicle as it is a safety provision that protects the driver and passengers. It allows the car to stop on the basis of friction, leverage and hydraulics which work together.

How it Works

It is mounted on the firewall at the back of the engine. For cars that are fitted with disk brakes, they use power boosters which multiply the pressure or force applied by the driver’s foot on the brake pedal. The power booster is the component in which power is multiplied by using vacuum created in the car’s engine.

Parts of a Brake Booster

A brake booster is made up of five parts which include; body, booster piston, booster return, control valve, reaction valve and a spring. It has two components where one keeps pressure at a constant level and the other varies the amount of pressure in the chamber. They are separated by a diaphragm.

Categories of Booster Brakes

They are classified in two main categories as found in most type of passenger cars. Remote boosters are fitted in the hydraulic lines. For firewall mounted types, the master cylinder is fixed on the front of the booster. This is the most common type of booster brakes and it is also referred to mastervac types.

Troubleshooting a Brake Booster

There are certain problems associated with a brake booster. To determine if it is good condition, turn off the engine and press and release the brake a few times. This ensures that there is no vacuum in the booster. Follow this by firmly holding down the brake pedal and turning on the engine. When the engine turns over, the foot should experience a slight give which indicates the booster is working properly.

Maintenance and Care

Depending on the condition and usage of a car, a booster brake can last up to 30 years while still providing efficient service. However, damage and wear and tear due to different causes easily degrade its condition. It is advisable to check the booster while changing the master cylinder.

Inspect the master cylinder regularly for leaks or damage as brake fluid decomposes the diaphragm found in the booster. Proper maintenance of components in the braking system such as calipers, rotors, brake pedals, hoses and master cylinder allows the car to run efficiently.