What would cause air in my pump when it turns off? I think I probably have a gap between the gasket and the lid as when the pump turns off a little water comes out. I am thinking this lets air in...I tried lubing the gasket and tightening the lid hard, but it seems every time the pump turns on there is a bit of air in the pump, as soon as its running for 5 seconds there is no air and no leaks of water...Should I replace the gasket or any other thoughts? It seems like both pumps do this. The gaskets look visually good.