Here’s a question that is easy to answer: When you start your car with your foot on the brake pedal and applying modest pressure, does the pedal depress when the car starts?
Randy
1969 E-Type 2+2
Randy, if there is still a reserve of vacuum in the reservoir, you probably would not feel the pedal move when starting the engine. But, if you first exhausted all the vacuum, then held your foot on the pedal, and then started the engine, you probably would feel it move.
Tom