Player piano vent block diagnosis

[Kerry Cooper]

A few quick sharp jabs on the pedals will give the required vacuum to lift 
the valves to stop them from sphering, as the valves are up side down.
Once the valves close, the pedalling should be good. Some times it takes 5 
or 6 quick sharp pumps to do this.

Best of luck.

Kerry Cooper
----- Original Message ----- 
From: "Greg Graham" <grahampianos@yahoo.com>
To: <pianotech@ptg.org>
Sent: Wednesday, March 02, 2005 2:46 PM
Subject: Player piano vent block diagnosis


>I wanted to call this subject "Players suck" just to
> get some attention, but refrained.  Technically
> correct, but often mistaken for a disrespectful value
> judgement.
>
> My problem:  customer's Laffarge upright player, built
> 1919, player action nicely rebuilt 1970, still very
> clean and tight, works great, EXCEPT...
>
> When starting a roll, there is the sound of a major
> vacuum leak.  The spool turns slowly, but no keys
> play.  You have to turn the electric vac up to full
> power, something pops shut, then the piano plays
> perfectly, even after slowing the vac back down to the
> minimum.  The pump is tight, the motor is tight, the
> action stack leaks only a little at the end gaskets.
>
> I think the action cutoff "gate box and vent block",
> between the pump reservoir and action stack is
> malfunctioning.  It appears externally to be exactly
> like the photo in Reblitz's "Player Piano...", page
> 106, Illus. 6-17, third printing, 1986.
>
> I didn't have time to take it apart, but was hoping an
> expert would have an idea why this valve would be slow
> to close, needing very high vacuum.  Any advice?
> Quick fix?  Something else wrong?
>
> Greg Graham
> Closet player piano aficionado in denial
>
>
>
>
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