Engine Vacuum and power brakes ?

Someone mentioned earlier that the vacuum goes high when you first let off the gas (ie higher RPM, closed throttle) the vacuum booster then gets "charged" to whatever amount of vacuum is available. Assuming you check valve is functioning correctly and rhe booster does not have any leaks, you now have enough vacuume to apply the brakes with boost.

Same woukd happen if you shut off the engine while driving. Yoj should have enough vacuume for 1 assisted brake.

Now stop and go is a diferent story!