leaking windshield washer fluid

[Fifty150hs]

Ok, we're in bizarro world here. I have an on going washer fluid leak. It's not the pump grommets. I've gone so far as to remove the tank and fill it with water and checked. Water flowed out of the pumps until it got low enough that it stopped. Still no leaking at the grommets. Filled the system and the fluid leaks out even if I don't use the washers. What I have noted is that sometimes there is washer fluid pooling on top of the cabin air filter cover. Even when I don't use the washer pump. The washer fluid container gets drained to the bottom of the pump intakes. I can't figure out what is causing the fluid to be drawn out of the tank. Anyone have any ideas?