I would suggest that first test the pump by removing the hose going
from the reservoir to the stack and seeing if closes and stays closed.
With a gauge at that point it should easily read thirty inches vacuum,
which is enough to play that piano _loud._   I set the reservoir
[regulator] to twenty inches as I don't like these pianos to beat
themselves to death.

The motor is an 1140 RPM motor as in all the Wurlitzer pianos I have
seen except the Violin Flute Pianino that sometimes have 1725 RPM
motors depending on the gear standard.

Don Teach
Shreveport, Louisiana