I've been getting air bubbles in return lines for a while when hooking up vacuum hose but now they occur anytime the input line selector (Hayward Dial-a-flo) is moved off center. It doesn't matter which direction it's moved - one line is from skimmer, the other from a frog grate in side of pool. Bubbles appear under pump basket cover and get heavier as the valve is moved towards one port or the other. Tried shaving cream idea on everything around pump - union, 3 port valve, basket cover, drain plug but nothing indicating a leak. Could I possible have leaks in both input lines? Hopefully not since they're all under carpet covered concrete.