I have a 1.6 liter per flush Kohler toilet - about five years old. This is my problem. After I flush, all goes well. The water tank fills up and stops filling as it's supposed too. This about fifteen minutes later, however, the water tank slightly overfills and thus begins to pour into the overfull hole. This is very gradual. I put a new flapper on it and it is not leaking. Seems like the float level is OK as well because it stops short of overflow when toilet is initially flushed.
What is causing the slow overfilling of the water tank and how can I fix it?
Any assistance is greatly appreciated.
Frank