To test a vacuum brake booster, with the engine off pump the brakes about 6 times. This will deplete the vacuum in the booster. Now, with your foot planted on the brake pedal, start the engine. If the booster is working, you will feel the pedal sink below your foot as the booster responds to the vacuum. If the pedal does not sink either the booster is bad, or you have no vacuum to the booster.
If the booster checks out OK, then you have a hydraulic problem or a friction problem if the brake pedal is hard to press to stop.
I have done the test with pumping the brakes and doesn't work. I don't feel the brake booster is bad as the brakes were working fine before I changed out the valve and it also had vacuum as it was released once the valve was removed.
The valve only vacuums in one direction and this direction is towards the engine, now when I removed the valve from brake booster, there was no vacuum in the hose from the brake booster connection, air was not being sucked into the valve, even with the hose still connected to the engine. I removed the hose that is connected to the engine, and the engine wanted to stall, which means air is being sucked into that port.
I am not able to get vacuum into the brake booster, since the direction of vacuum is towards the engine and the valve is not sucking air out of the brake booster, when the hose is connected to the engine port, but there is vacuum there. I blew through the hose and it was not blocked also.
WTF? I cant believe this lol