Brake question....

Here are the methods for testing a brake booster for holding vacuum.

1) Engine off, depress the pedal until it is hard (no power assist). Hold that hard pedal down, start the engine. Pedal should continue further down with engine vacuum.

2)Turn the engine off. Power assist should remain at the brake pedal and not leak out. As in, turn the engine off, come back an hour later, you should still not have a 'hard' pedal.