I'm having a problem getting the damper lift pneumatic to function
properly on my Mason & Hamlin Ampico A.

When the damper rail return spring is attached as per factory, the
pneumatic does not want to lift the dampers.  Removing the spring
solves that problem but then the strings don't dampen completely or
properly.  I have been experimenting with adjusting the tension of the
spring but am not getting satisfactory results.

Also I notice the damper rail lifts more at the end next to the
pneumatic and so the treble dampers need to lift much higher for the
bass dampers to clear properly.  Obviously the original spring tension
from the factory was workable.  The pneumatic is recovered properly and
the valve is working properly, unless this valve, as well as the hammer
rail lift valve, should be set differently?

I don't want to go any further with this until I get some input from
people who really know what's going on here.

Many thanks.

Dave Krall

 [ That the piano has the "original spring tension" is the same as
 [ saying it still has its "original factory tuning"!  Steel under
 [ tension stretches continually; that's why the piano is re-tuned
 [ regularly, and damper springs replaced.  Look for other problems,
 [ too, such as a leak somewhere in the soft-pedal pneumatic and
 [ related plumbing.  -- Robbie