Winterizing on Saturday included draining the water tank - into the bilge. Then couldn't get my manual bilge pump to take a suction. This is the same pump that gave me fits last winter after having been installed upside down for 40 years (yeah, suction was on top). Last year I flipped it over and redid the piping, but this year it acted up again!
Off to Defender for a new pump (Bosworth Guzzler 400) - it fits. Took a suction first stroke and pumped the bilge. A thing of beauty.. I notice they've gone from 6 bolts to 12 bolts around the diaphragm.
Brought old pump home for autopsy. Seems the discharge valve flapper had just enough set in it (hanging open for 40 years) that the air flow wouldn't close the valve, hence the pump wouldn't prime. Flipped the flapper over and the pump works fine. Now I've got another spare..