How to Refill a Leaking Fluidmaster Line

Turn the handle of the water supply clockwise to stop the flow of water to the toilet. Flush the toilet to remove all the water from the tank. Lift up the lid of the tank and soak up the rest of the water with a sponge.

Turn the coupling nut at the bottom of the toilet using a wrench. If this is the line that is leaking, remove the coupling nut from the supply valve coming out of the wall. Replace the line with a new flexible line, turn on the water and test the unit. If this doesn't work, you'll need to replace the Fluidmaster refill valve.

Turn the locknut holding the fill valve in place at the outside bottom of the toilet tank. Lift up on the valve body to remove it from the toilet tank.

Place the new washer on the bottom of the Fluidmaster valve.

Measure from the bottom of the toilet tank to the top of the overflow line. Add an inch to this measurement. Turn the body of the Fluidmaster valve to raise the height of the "CL" mark on the side of the valve to this height.

Press the bottom of the Fluidmaster valve to the bottom of the toilet tank. Screw the locknut to the bottom of the valve. Connect the water line to the valve, turn on the water and refill the toilet.