(Kohler Rialto one piece toilet, model 3397) I think I have two problems. 1. The water continues to run (very slowly) when the tank refills after a flush. Lifting up on the float makes it stop but it then starts again after a short time. I replaced the internal water valve but no change. 2. Looks like the flapper leaks. I filled the tank and turned off the water input. After a half hour the tank was empty. It must have drained out around the flapper. I bought a new flapper but it didn't help. Although its a Kohler flapper for my toilet, it doesn't seem to fit properly?? Any advice is greatly appreciated.