Vacuum Brake Booster: Description and Operation

Brake Booster

The brake booster provides assistance by reinforcing the driver's effort when braking. The reinforced assistance provided by the booster is proportional to the driver's effort applied to the brake pedal.

The brake force applied by the driver is increased by the booster in a ratio of 6.5:1.

The vacuum used to operate the booster is formed in the engine's intake manifold. The booster is connected to the intake manifold by a hose.

The booster is fail-safe therefore, if a fault develops in the vacuum unit, the braking system will still function. However, the driver will have to apply a greater force to the brake pedal to slow down the vehicle.