If you notice a crack in the toilet tank, you will have to act immediately to make sure it does not overflow and completely ruin the tank. Anything larger than a small crack will need to replace the reservoir, so try to repair the crack only if it is 1/16 inch wide or narrower. You can stop the leak using a liquid silicone sealant to seal the tank.
American Standard 3195A101.021 Champion PRO Right Height Elongated Toilet Bowl, Bone
Instructions
1 Open the water connected to the toilet bowl by turning the small knob behind the toilet cistern to the right.
2 Empty the toilet tank by hitting the discharge lever after turning off the water.
3 absorb all the excess moisture with towels.
4 Blow the inside of the tank completely dry using a hair dryer. If you wish, you can allow the tank to air dry, but this can take hours. Make sure the tank is completely dry before proceeding to the next step.
5 Wear safety glasses and rubber gloves. Apply a test line of epoxy water to silicone pipes over the crack, starting 1/2 of an inch before the crack and ending 1/2 inch beyond it.
6 Slather the epoxy water test silicone pipes without problems on the crack, using a spatula.
7 Allow the water-resistant epoxy silicone plumbing to dry for 24 hours.
8 Close the water to the bathroom again and let the tank refill.