Some times my pump basket has water filled in it that it looks like there isn't any water in there at all. Other ties there is n air pocket (gap) between the top of the basket and the lid. Other times there are big air ripples/waves in the basket. I have inspected the gasket/rubber tube around the inside of the lid and it looks ok to me, but I can't get it out. Whats the trick to get it out. I haven't really checked any other places for air leaks.