Following on from the recent query about Theme valves, the same valve
box on the Weber Grand Duo-Art I've just finished has the two valves
which operate the pneumatic tracking system.  I rebuilt the box and
replaced the pouches.

The Theme valves work fine (mine went back easily), but I am getting
rude noises from one of the tracker system valves.  It only happens
when the outer holes are active, so the tracking is "nearly" right, but
when the left side hole is nearly closed by the roll, its associated
valve starts to flutter noisily, rather than snapping closed and moving
the tracker bar.

I thought perhaps the bleed was too small, preventing the pouch from
collapsing when it should, but enlarging the bleed has only achieved
marginal improvements and I feel it is now too big.  (When I dismantled
the box the original bleeds were missing and there was a piece of tape
with pin holes as a substitute -- this problem is obviously not new!)
The noise from the valve is quite noticeable.

Has anyone else experienced this problem, and what is the likely
solution.  Does anyone know what the valve clearance should be?
Perhaps it's too big.  I can't detect any leaks anywhere between the
tracker bar and the valve box, and this only seem to happen on the
one valve.

John Farmer, UK
http://www.musicanic.com/