Brake Booster Operating Test
- Start the engine for 1 - 2 minutes and stop. If the brake stroke gradually reduces when the brake is pressed for several times, it means it works properly. But if the brake stroke doesn't change, inspect the check valve, vacuum hose and booster.
- Turn the engine off. And press the pedal for several times until the brake stroke reduces. And then, start the engine and press the pedal. When there is no change in brake stroke, it means the brake works properly. If it is not, inspect the check valve, vacuum hose and booster.
- Press the pedal and stop the engine when the engine is running. Press the pedal for 30 seconds. When the position is fixed, It means that there is nothing wrong in the check valve, vacuum hose and booster. But if the pedal tries to return to its original position, the one before pressing, inspect the check valve, vacuum hose and booster for proper operation.
The booster can be seen that it works properly if it passes all three tests stated above. But if it fails to one of the tests, check the check valve, vacuum hose and booster.