Install New Fill Valve and Connect Water Supply Line

What happens here

Insert the new Fluidmaster fill valve into the hole at the bottom of the toilet tank. From underneath the tank, thread on the plastic mounting nut by hand until it is snug. Then, use adjustable pliers to give it a final quarter to half turn, ensuring it's secure but not overtightened. Finally, connect the new water supply line to the threaded connection at the bottom of the fill valve. Hand-tighten the plastic nut on the supply line until you hear a click, indicating a secure seal.

Goal: Secure the new fill valve and reconnect the main water line