Toilets usually leak from one of two locations—either the wax gasket at the floor or at the connection between the tank and bowl. If you find that the bowl is getting wet from a tank leak, then the most likely problem is a broken seal at the tank-to-bowl gasket or around the washers of the bolts. Here’s how to fix the problem with some simple hand tools.
STEP 1: Purchase a tank-to-bowl toilet repair kit. They’re usually available at hardware stores and most include a new gasket plus replacement bolts.
STEP 2: Shut off the water supply to your toilet by turning the valve handle on the wall clockwise. Then flush the toilet and hold the lever to drain the water from your tank. Remove any excess water with a cup and rag. Place a bucket beneath the tank to catch any excess water.
STEP 3: Disconnect your water supply line from the threaded connection at the bottom of the tank.
STEP 4: Remove the pair of old nuts, bolts, and washers from the toilet tank. Use a wrench to hold the nut at the bottom of the tank so it doesn’t spin, as you unscrew the bolts inside the tank using a screwdriver.
STEP 5: Carefully lift up on the tank from the bowl and remove the old tank-to-bowl sponge gasket. Take the opportunity to clean off any grime or mildew left by the leak from the surface of the bowl and tank.
STEP 6: Place the new red sponge gasket over the mounting nut threads.
STEP 7: Carefully center the tank and set it onto the bowl so the gasket seats snugly into the bowl’s water inlet.
STEP 8: Use the new bolts, rubber washers, washers, and hex nuts, to reattach the tank to the bowl. Apply downward pressure to keep the tank level as you tighten the bolts, alternating from left side to right side, until the tank is stable. Be careful you do not over-tighten the nuts, which may cause the porcelain to crack.
STEP 9: Reattach the water supply line.
STEP 10: Turn the water supply to complete the repair.
Behold the beauty of this non-leaking toilet tank.