[ Ron Evans wrote in 141115 MMDigest:

> I have a late 1920's Marshall & Wendell player with the Ampico A
> system.  My grandfather rebuilt the piano in the vicinity of 1970
> and nothing has been done to it since then. ...  I played a roll
> recently, only a few keys near the center played while the others
> just moved a bit.

I would not worry about the primary valve chest.  Unless there is
extensive insect damage, or if it is a very early model where leather
is actively turning into powder, it is one of the last problems you
will find in this unit.

The most likely problem you will find is in the secondary valve blocks.
These are often popping apart at the glue joint at the pouch mainly
from the spring tension.  I have done many of these and the ones we
have done most recently are Ampicos that have been rebuilt years ago
when everything was not totally necessary.  These by now are needing
some of the rebuilt items redone and all the items that were not
rebuild previously redone.  There is a 90% chance that these valve
blocks will need complete rebuild.

Also, when you say it started playing but after a while it no longer
played, I would suggest that the rubber on the striker pneumatics began
falling off the cloth in powder form and was possibly sucked into the
system as it loosened.  If this did not happen with the strikers, then
the rubber in the expression system cloth was doing it as well.

To test my theory, you may remove all the secondary blocks and use
masking tape to close the holes to them on the decks.  Also tie off the
note tubes or find some other way to close all the tubes going to the
primary.  Then suck on the stack and see how airtight it is.  The long
machine bolts through each end of the stack could be loose and leaking
if there is still a leak in the stack, but I suspect that you will find
an airtight stack with the secondary valves removed and the holes taped.

The next most likely problem, after the stack valves are rebuilt,
will be the large pneumatics in the expression system and crescendo
pneumatics.  These will likely have leaky cloth at this age.  You may
disconnect the tubes to those and blow on them to see if they are
leaky.

I have rebuilt several sets of these Ampico valve blocks for several
folks on this group in the last few years, so if you are open to having
it done, just contact me.  All work is guaranteed.  Yes, we do
piecemeal restoration when needed as well as complete jobs.

The pump could be a problem but it would be way down the list on likely
problems to check.  It will likely have the spill adjusted so that top
pressure out of the pump will be 30" to 34".  It won't be 120+ inches
like the Duo-Art pumps without a spill on them.

Doug L. Bullock
St. Louis Metro Area
http://thepianoworld.com/