[C320-list] Head pump squeal

[Robert Seastream]

Hi Guys:

Over the past weekend, the head pump started squealing/screeching.  
It's not the pump rod, but seems to be coming from inside the pump as 
if it were the pump mechanism (bellows?) itself.  I can't  believe a 
wastewater pump would need lubrication.  This boat is a lightly used 
2002 model year, so I don't think the head pump should need servicing 
either.  Any thoughts?

Bob Seastream
Intuition, hull 906