The brake booster is an appliance that helps enhance the effects of the hydraulic braking system in cars as a supplement to the primary braking mechanism. Every time you push the brake pedal, the force transfers to a rod. This rod passes through the brake booster and reaches the master cylinder. The pressure from the rod activates the master cylinder piston and works on the hydraulic braking systems.
The brake booster chamber encompasses a vacuum the engine creates. This chamber has two units, separated perpendicularly by way of a rubber diaphragm. When the brake pedal pushes the rod, a small amount of air is let into the chamber on the brake pedal side through a valve that also seals off the vacuum. This air pressure on one side of the diaphragm helps enhance the force of the brake.
However, in instance of cars that have turbo charging or use diesel as fuel, the engine does not generate the necessary vacuum. As a result, they need an additional brake booster vacuum pump to draw out the air and create the vacuum needed for the brake booster to operate. Vehicles that typically run in locations of high altitude also need a brake booster vacuum pump.
The brake booster vacuum pump reduces dependency on the engine for the vacuum and can work independently of it. This device uses an electrical regulator circuit to work. It activates with a signal from the brake booster vacuum sensor that monitors the levels of the vacuum in the brake booster.
Facts to Note:
The brake booster vacuum pump should be able to sustain up to 18” of vacuum for the brake booster to be effective.
If you notice that the pedal has slipped to the floor of the car and you hear a hissing sound, this could be a sign of a leak in the air line or pump to the brake booster vacuum pump.
How to Fix:
The battery is cut off. The defective brake booster vacuum pump is located and known. The vehicle is raised and supported on jack stands as required. The engine under shield is detached for access.
The brake booster vacuum pump hoses and electrical connector are detached. The brake booster vacuum pump is removed from the mounting bracket.
The new brake booster vacuum pump is fixed onto the mounting bracket. The hoses and electrical connector are fixed to the new brake booster vacuum pump. The battery is rejoined.
The brakes are tested for proper brake booster vacuum pump operation. The engine shield is reinstalled. The vehicle is removed from the jack stands.
The vehicle is road tested and checked for proper brake booster vacuum pump and brakes operation.
If you observe the brakes are not responding as they should, book an appointment with one of your expert mechanics and have the brake booster system completely examined. The mechanic will check the brake booster vacuum pump for damage and advise you if it needs changing. Refer to the owner’s manual for recommendations on the frequency in which you must have the brake booster vacuum pump changed.
Common symptoms indicating you may need to change the Brake Vacuum Pump:
Delayed brake response
Excessive pressure is needed to make the brake respond
A hissing sound when you press the brake pedal
Brake pedal slips to the floor of the car when the engine is running and the car is stationary
Braking becomes especially difficult in heavy traffic areas when the brakes need to be applied in quick succession
Importance of this service:
A malfunctioning brake booster vacuum pump will not produce the adequate vacuum needed for the brake boosters or power brakes to function. This undermines the effectiveness of your brakes and can be a safety hazard.