I just replaced my trim motor/pump and it works fine except it seems now that I have some air trapped in the system. As I raise it and lower it, the motor will whine and seem to be pumping air. It does this intermittently. I tried lowering it and raising it a few times, each time removing the fill cap and letting a nice puff of air out. I have the old type with the stupid fill cap on the side of the motor and this makes for a huge mess! Just wondering if anyone can give me any pointers on the right way to do this. Thanks.