I have a traditional American Standard toilet. I have replaced the tank-to-bowl gasket and flush valve.
When I reattach the tank to the bowl, water is consistently (drop every 15 seconds) dripping from the right screw-bolt assembly. Inside the tank (on left and right), I have the bolt, metal washer, and rubber washer. On the bottom of the tank, I've got the metal hex nut. I then put the tank on the bowl and use plastic wing nuts to attach tank to bowl. The left side seals fine; the right doesn't.
I took the tank off and replaced the rubber washers. No luck. Everything seems tight. I'm afraid to tighten the metal hex nut too tight for fear of cracking the porcelin (sp?), but it's tighter than hand-tight. Also, the tank wobbles back and forth a bit. Could this mean the gasket is too big (it's slightly thicker than the old one). Nothing seems to the leaking from there.
Advice? Someone suggested using tub-type silicone under the rubber washer (if yes, how long should I let it dry?). Also, what about using a rubber and metal washer between the metal bolt and the bottom of the tank? How about a new toilet? :)