Brake Booster Operating Test
WARNING: This page is about a different car, the 2024 Kia Forte. However, it is still accessible from the selected car via links, so may be relevant.
For simple checking of the brake booster operation, carry out the following tests.
- Run the engine for one to two minutes, and then stop it. If the pedal depresses fully initially but gradually becomes higher in the successive attempts, the booster is operating properly. If the pedal height remains unchanged, the booster is inoperative.
- With the engine stopped, step on the brake pedal several times.
Then step on the brake pedal and start the engine. If the pedal moves downward slightly, the booster is in good condition. If there is no change, the booster is inoperative.
- With the engine running, step on the brake pedal and then stop the engine. Hold the pedal depressed for 30 seconds. If the pedal height does not change, the booster is in good condition, and if the pedal rises, the booster is inoperative.
If the three tests above are satisfied, the booster performance can be considered as in good condition.
Even if one of the above three tests is unsatisfactory, check the check valve, vacuum hose and booster for malfunction.