How to Test brake booster?

Answer:

Answer

Apply vacuum test to the booster. If it does not hold vacuum it is defective. You can borrow a vacuum gage at most auto parts stores.

You could go lazy man's style and just take the vacuum line off of booster. If the brakes are as hard as concrete, then put it back on and the pedal is smooth, you got yourself a decent working unit.

Contributor: Clay
First answer by Clay. Last edit by Snuttall53. Contributor trust: 0 [recommend contributor recommended]. Question popularity: 13 [recommend question].