What Is a Brake Booster?
It is a cylinder setup that’s been innovated for the purpose of reducing the pressure on the pedal needed for braking. It involves a booster setup to move with the main cylinder to provide a higher hydraulic braking pressure or so that lesser force is needed for the brake pedal through a brake-booster push-rod.
How Does a Brake Booster Work?
When you step on the brake pedal, the linkage that you have on the pedal will cause a shaft to move forward to respond to your foot, while this is happening, it will connect with the brake pedal and master cylinder. There is a diaphragm in the brake booster that divides the interior into two that is both in a partial vacuum. While your foot is on the brake pedal, it will cause the valve in the booster to open that will let the air into one side of the booster. This kind of pressure on one side is going to help in pushing the brake master cylinder piston forward to interact with the brake pedal, which this is going to slow down your vehicle.
Video Source: https://www.youtube.com/watch?v=Uj2TSG3eRoc
How To Tell if a Brake Booster is Bad?
Disc brakes made it possible for power-boosted braking systems to exist in every vehicle today. Disc brakes need a brake booster so the pedal effort is manageable for the driver, but you will know if they go bad. When you need to exert more pressure on the hard pedal than usual, and it takes a longer distance before your car stops, then you have a bad brake booster. The hard pedal is an indicator that there is not enough boosting power.
How To Test a Brake Booster?
If you want to perform this test, you need to park your car first, do not step on the brake pedal, and then turn the ignition to start the engine. Allow the engine to stay idle for two minutes and don’t do anything. Right before turning off the engine, step on the brake pedal and hold it there. Turn the car engine off, while you continue to step on the pedal for 30 seconds more. If you do not feel anything from the pedal when the engine starts, this means that the brake booster is not working.
You can do another test by performing one on the vacuum system because this gives power to the brake booster. In order to perform this test, you have to start and run the engine while staying at medium speed, then turn the ignition off and remove your foot from the gas. Let 1 minute and a half past before applying the brakes. The vacuum boost should be felt on about two braking applications. If you don’t feel anything, the vacuum might have a system leak.