Step 4 · Install New Fill Valve

This is the step people usually slow down on. Go finger-tight first, then a quarter turn. No rush — replay the clip whenever it helps.

Now, install the new fill valve. First, adjust the height of the new fill valve according to the manufacturer's instructions; typically, you twist the shaft to extend or shorten it. The top of the fill valve should sit about 3 inches above the top of the overflow pipe. Insert the threaded shank of the new fill valve through the hole in the bottom of the tank. Make sure the included rubber gasket is seated properly on the inside of the tank. From underneath the tank, thread the plastic locknut onto the fill valve shank. Hand-tighten the locknut until it is snug. Then, use your wrench to give it an additional quarter to half turn. Do not over-tighten.