In response to Mike Walter's question about his pump knocking, refer
to http://antiquemechanicalrestorations.com/3_Ampico_A.html 

The Ampico B pump body is the same as an Ampico A.  Pump noise is
usually from the pump arms or from a feeder hinge.  If the noise is
a low pitched thump it is probably caused by the pump hinge.  Photo
A 23, along with the text, explains how the noise can be caused by
a bad glue joint with the triangular spacer at the hinge end of the
feeder.  This may be the cause of your problem.  If your restorer
did not break apart the old glue joint and re-glue the spacer, the
old glue joint could have broken apart.

Photo A 25, along with the text, shows how to make a tight hinge
before covering the feeder.  A weak hinge with play in it can also
cause a thump.

If the sound is higher pitched then check the pump arms as in photo
A 2.  If your pump arms are misaligned, new bushing cloth will quickly
wear out.  The metal pins on each end of the wooden crank arm must be
parallel to one another to distribute equal force on the bushing cloth.
The fact that the bushing cloth has been replaced twice on your pump
could point to a misalignment problem.

Paul Manganaro