The Fluidmaster Pro 45 valve is an anti-siphon, adjustable toilet fill valve. The valve can be adjusted from nine to 14 inches long. The Pro 45 has two adjustments. One adjustment is on the shank of the valve. The other adjustment is a screw type that is between the cap and the float for fine adjustment. The Pro 45 can be used to replace most other float valves on most toilets.
Turn the toilet water supply valve, which is normally located on the left side of the toilet under the tank. Pull the lid off of the tank, and set it in a safe location, so it does not break.
Flush the toilet, and hold the handle down until as much water as possible drains out. Wipe the remaining water out with a large sponge. Loosen the nut connecting the water supply line to the shank of the valve with channel lock pliers and remove it. Remove the second nut that mounts the fill valve to the tank. Pull the old valve out.
Remove the new parts from the box. Cut the cone washer from the middle of the shank washer. Push the shank washer on the shank of the Pro 45, smooth side up. Insert the shank of the Pro 45 into the hole where the old valve came out, and check the length. Find the line at the at the top of the float, and adjust it to one inch above the overflow tube.
Adjust the valve by holding the top part of the valve and turning the bottom of the shank. Place the Pro 45 back in the hole once the proper height is obtained, and screw the plastic mounting nut on the shank with the channel locks, but don't over-tighten the nut, so as not to crack it.
Screw the supply line nut on the shank hand tight. Turn the water supply on and fill the tank. Check for leaks. Replace the toilet lid. Flush the toilet, and check for proper operation.