[ Robert Nicol wrote in 181102 MMDigest:

> I am puzzled by the fact the Tempo lever can force the action into
> play, and if I cover the reroll port in the transmission frame the
> notes will play during reroll, but not when I uncover the port and
> put the lever back into play.

Robert,  number one, the problem you have is probably not in the
bellows.  If it were, your piano would not play when the rolls indicate
it should.  Another symptom is playing while in reroll.  Both cures
mean dropping the bellows, the heaviest unit of the player, difficult
for those of us who do this work, nigh on impossible for the owner.
Again, not your problem.

Your clues appear to be a slight leakage somewhere along the line that
goes to rewind.  There are several possibilities:

1. When you put a new roll on, wind it on by hand until the hole in
the take-up spool is well covered.  Add a little tension so the roll
is tight over the hole.

2. In the transmission, a plate slides over a hole that opens or closes
as you go back and forth between play and rewind.  The two faces must be
flat.  Lube with Vaseline to prevent seepage.  There should be a coil
spring that fits around the stem of the brass plate to hold it against
the transmission.  If it is missing you should replace it.

3. How do conditions look around the hole in the take-up spool?  Any
grooves, cuts, splits, etc. that may allow air to leak in?  If so,
fix the problem and move on.

4. Remove the take-up spool by pushing it left and disengage on the
right.  Check the condition of the insert on the left end.  There is
a small circular bearing and under it some spacers, usually leather.
Pry the bearing off with a small screw driver.  Check the condition of
the spacers.  If bad, make new ones.  Put them back in but wipe them
with Vaseline or an equivalent to seal any air leaking in.  Also, the
prong itself should push snuggly into the hole in the take-up spool.
Push it back and forth, it should follow quickly and easily.  Lube if
necessary.

5. What is the condition of the Play-Rewind switch itself?  Was it
replaced in the rebuild?  It was made of pot metal, and cracks and
leakage can form.  The plates that slide on each other may be "dry" and
air may be seeping under them.  Clean the plates until they are smooth
and wipe them with Vaseline to seal against leaks.

All that said, you may have a problem related to the valve that operates
the rewind pneumatic.  The bleed may be slightly plugged, the pouch may
be leaky or stiff, the valve may be slightly leaky.  What started life
at the factory as decidedly "on" or "off", is now maybe or sometimes
"on" or "off".  Welcome to a rebuilders world!

Jeff Davis