We have had an issue with apparent air locks in our water system. No problems when attached to hose, but when using the water pump, we first noticed gauge wasn't showing full when tanks had been filled. We were able to fix this by blowing through a tube. Next we switched from hose to pump yesterday and no water even though gauge showed tanks half full. When we added more water, pump worked normally and totally drained the tank. We measured water to be sure it was drawing it all out. Problem seems to occur once tanks get to 1/3 level. Any ideas? We have a 2015 Crusader Model 294, which we have owned for a little over a year. We absolutely love it and have had no other issues, but this one is a real puzzle.