Hoover TeamVac leaking

Last year the machine worked without leaking, this is a new problem. The machine is a few years old and I don't use it very often. The tank does not leak when I fill it and place it on the counter. Once I put the tank into position, the water practically flows from the bottom of the unit, this is more than a slight leak. Everything else, suction, brushes, are working fine. I haven't tried to remove the panel on the bottom to check the hoses, inside. Any ideas?