I am attempting to correct an Ampico intensity pneumatic that will 
not lock in the 'on' position as it is supposed to.  The diagram in
the Ampico Inspectors Reference booklet has an illustration of an
Ampico expression unit but the details are quite indistinct, even
in an original copy from the AMICA web site archives.

I am wondering if anyone has come across a really good diagram.
I found another diagram of the expression unit that, though very
small, it was for the earlier style that doesn't look at all like
the simplified "A" style.

Bill Chapman - in rainy La Quinta, Calif.