How to fix a toilet leak after you've installed a bowl gasket
QUESTION: I installed a toilet bowl gasket, now it leaks when I flush it. What is causing the leak?
ANSWER: Pull up the toilet and inspect the drain, gasket and bowl for signs of water. Check the fit of the gasket onto the horn. If the horn is out of round you can file and sand the porcelain so the gasket will easily slide over the horn. Check the O-ring position for twisting. If you are using a 4” sleeve on the 3” gasket is there a thin O-ring between the 3” gasket and the 4” sleeve? Look for any signs of cracks in the drain, the gasket and the toilet bowl. Many times the bowl will leak underneath before the gasket and drain.