Hi All; to Thomas West -- I have a whole series of articles about the
common problems with the modern Aeolian players at

  http://www.player-care.com/aeolian-list-problems.html 

By far, the most common problem is the air motor, both valve leakage
and internal wood leakage.  See

  http://www.youtube.com/watch?v=v128CZP8E_0&feature=share&list=UUTueApG5FoL-JTsw6uJYmFA 

It's easy to find out if the air motor is one of the culprits.
Just disconnect and plug the hose where it goes into the air motor.
Then pump the pedals and see if there's a difference in resistance.

Secondly, understand that it only takes about three leaking block
valves to drag the system down to nearly inoperative.

Another not-so-obvious problem is the regulation of the stack to the
keys and the regulation of the piano action itself.

Also, be sure to tighten the nuts that hold the stack together.  They
are "always" loose.  By the way, I'm not talking about the wing nuts
that are used to hold the stack in place.

Lastly, I have sent postings to the MMDigest about most of these things
over the years.  So, check the Archives/Author: John Tuttle.  I have
about 500 customers with modern Aeolian players, and the vast majority
of them work fairly well.  They are by no means a quality product, but
then they sold for less than $2000 when new, generally $1395 to $1695
on sale.

Musically,
John A Tuttle
Player-Care.com
Brick, New Jersey, USA