How do I stop water from leaking past the lavatory or bathroom sink drain?
It is likely that the pop-up or stopper is either not seating far enough into the drain body or that the sealing surface is dirty or damaged. The pop-up or stopper uses an O-ring or gasket to provide a water seal and keep water in the basin. The gasket and the surface it seats against must be clean and smooth. Replace the gasket if necessary. If the stopper is not seating far enough into the drain body, adjust the travel of the ball lever arm. This arm is usually below and behind the basin. It protrudes from the drain body and connects to a lift rod with an adjustment clip. Vandal-resistant drains will require that you remove the ball lever arm from the drain body in order to remove the stopper for cleaning or replacement.
