Toilet tank to bowl leak. Which part is leaking?

[Goalie35]

I have a slow tank-to-bowl leak, but not positive which piece is causing the problem. Tried the dye test, to make sure & sure enough, dye flows into the bowl. When I turned the water off, the water level in the tank slowly drops, leaving about an inch of water at the bottom of the tank (just about even with the edges of the seat of my mansfield flush valve).

To take a step back a bit...I started all of this because of a leaking wax ring. I fixed the wax ring pretty easily, but since everything was apart & all of the rubber components are getting older, I decided to do the "right thing" & replace just about everything, with the exception of the refill valve. Bought a new mansfield flush valve, bolts & rubber stoppers, & tank to bowl gasket. Replaced everything, but now have the leak to deal with.

I inspected the ceramic of the tank & don't see any cracks. I was a little worried because I tightened the nut at the bottom of the flush valve probably a little too tight. Also, if I press down just slightly onto the top of the mansfield flush valve, the leak stops.

I just can't figure out if the culprit's the flush valve seal, the entire flush valve, or the tank-to-bowl gasket. Or, if everything's fine & I just installed something wrong.

Thanks for your help.

 

[havasu]

Put a small weight on top of the flapper. Fill it up and let it sit for the night and see if the water level has gone down the next day. If not, it would be your flapper or the flush valve seal.