I have an Autopiano player piano with a double-valve Standard action
stack.  Both the upper stack and lower pumps have been rebuilt.
However, the springs load varies in the reservoirs: one reservoir
had a 15lbs X 8lg. and a 6lbs x 6lg as well as a heavy coil spring.
The other reservoir had two 6lbs x 6Lg. springs.  The pump is not able
to drive the stack but the motor works slow.  I used a vacuum cleaner
with a valve to reduce the vacuum and was able to play the test roll
successfully.

According to the A. Reblitz "Player Piano Rebuilding Manual" I saw now
coil springs.  What I would like to know is what were the original
factory springs.  Were all springs the same pressure?  Also, what
effect does the different load have on the volume of vacuum?  Steaves
Piano Supply list these springs as outward pressure springs.  What is
recommended?

Yours truly,
S. Lee Walker
Franklin, Indiana