Hi, due to my hard brake pedal, was checking my (new) booster, with engine off I pump the brake 4-5 times and hold it,
I start the car and the pedal drop about 1/2", do you think it's normal ?
And after letting the engine idle 2 minutes, I shut off the engine, I slowly remove the check valve on the booster and I ear nothing !
I think I should ear some air escaping right ? And yes I have vacuum on that hose and check valve is ok. Did check vacuum with booster hose installed and removed and same vacuum on engine so I don't have a vacuum leak there.
Could that booster be internally not good without a vacuum leak ?
That booster is new and also the master cylinder and all brake hose and line.

Any advice ?
71 442
Thanks everybody