Is the hole not there as a vent for the diaphram within?? (? long day, spelling way off), allowing it to move free ? , and would blocking it off not create a build up of pressure, and reduce the pressure created by the pump ?? I would think anything leaking from sed hole would mean the diaphram (? sorry) is split or splitting
new unit from Lighthouse 40 qid including VAT and delivery
Hope you made sure that the first leak hasn't just been diverted into your sump!Could cause costly repairs when you oil turns into SAE Zero with an octane rating.