Locate the shutoff valve behind the toilet and turn it clockwise to stop water flow.
Flush the toilet to empty the tank and hold the handle to drain remaining water.
Carefully lift the tank lid and set it aside on a safe surface.
Examine the flapper at the bottom of the tank for cracks, warping, or misalignment.
Remove the old flapper by disconnecting it from the flush valve and install a new one, ensuring proper fit.
Check the fill valve for debris or damage; replace if necessary.
Adjust the float arm or float cup to set the water level just below the overflow tube opening.
Tighten the tank bolts with a screwdriver or wrench to stop leaks; replace washers if they are cracked or worn.
Apply a small amount of silicone sealant around the base of the tank if you notice leaks or wobbling.
Turn the shutoff valve counterclockwise to restore water flow.
Allow the tank to fill and observe for continuous running or leaks.
Test flush the toilet several times to ensure it stops running and flushes properly.
Replace the tank lid carefully, ensuring it sits securely.
