We just bought a pedestal sink. When we put the assembly under it together, the ball connected to the pivot rod sprung a leak. Does anyone know how to fix this problem. We've tried everything we could think of, but I'm sure there has to be other solutions. We have tightened the retaining joint as much as possible. It's nice and snug, but the darn thing won't stop. Any suggestions would help. We can't afford a plumber.