testing brake booster

[truckinman466]

is there any way to bench test a brake booster? My original one is pretty rusty. before I try to clean it up, I'd like to see if it is any good.

[moparroy]

There are some u-tube videos on some basic tests which is what I did with mine though it was in decent shape. If its rusty check for vacuum leaks - and check the actuator valve. Actuator valve applies vacuum to both sides of the diaphragm until the brakes are applied - if its not working the brakes can self apply or no assist. For leaks see if it can hold a vacuum. Also test the external check valve but that's a separate part - for one way air flow.