Kohler San Souci toilet leak

[Davery5872]

I have an old one piece Kohler San Souci toilet that is leaking into the bowl. I have replaced the flapper (generic) and the gasket (kohler) under the flush valve. When I drained the tank, the leak was still there. I am at a loss as to how the water is getting into the bowl. Ideas?

 

[Twowaxhack]

Make sure the outlet end of the refill tube is secured above the water level in the tank if it has a fluidmaster ballcock.

Try a factory flapper.

 

[Davery5872]

The refill tube is above the water line. I drained all the water out of the tank, but there was still water leaking into the bowl. Where is this water coming from? Here is a pic with the flush valve removed. Is water supposed to stay in that cavity under the flush valve? We have two of these toilets and I just noticed the other toilet also has a small leak into the bowl.