Yes, the problem can be the trip lever adjustment. Does it drain well with the triplever/stopper removed?? If yes, it just needs adjustment. Where the stopper rod connects to the top lever, there is a clevis with a screw on the end of the rod. That needs to be adjusted up/down so water drains while it is up, and stops the water when down. No way to actually see where the stopper is, so it is trial/error type adjustment.