How to Make a Better Seal on a Mansfield Toilet Fill Valve Seal

The Mansfield toilet fill valve uses two seal discs in the top of the valve to stop the water when the tank reaches the full mark. If your toilet is constantly running, you must make adjustments to get a better seal. There are two adjustments that you can attempt to stop the toilet from running. If the toilet is still running constantly after the adjustments, you may need to replace the Mansfield fill valve.

Things You'll Need

• Phillips-head screwdriver
• Cloth

Instructions

1. Remove the toilet tank lid and set the lid aside. Locate the screw that secures the float ball arm to the top of the fill valve. Turn the screw in small increments clockwise, using a Phillips-head screwdriver. Do not turn the screw more than 1/4 turn total. If the toilet is still running you will need to repair the seals.

2. Turn the toilet water supply valve clockwise to shut off the water supply to the toilet tank. (The supply valve is located behind the toilet; it connects the house water pipe with the water line going to the bottom of the toilet.) Press down on the float arm slightly to allow the remaining water in the supply line to run into the tank.

3. Turn the top plastic cap on the fill valve counterclockwise and lift the cap off the fill valve. (The float ball arm connects to the top of the white cap.) Angle the cap and float ball across the top of the toilet tank out of your way.

4. Pull the white button off the top of the seal in the Mansfield fill valve and set the button aside. Pull out the upper and lower seal discs from the fill valve. Inspect the seals for cracks or damage. Take the seals to a plumbing supply store for replacements if necessary. Otherwise, clean the seals with a cloth or flip the seals over when reinstalling them.

5. Place the upper and lower seal discs back inside the fill valve. Place the white button in the indention on the top seal disc, and place the fill valve cap back on top of the fill valve. Turn the cap clockwise to secure the cap to the fill valve.

6. Turn the screw that secures the float ball to the top of the fill valve 1/8 turn clockwise, using a Phillips-head screwdriver. Turn the water supply back on to the toilet. Flush the toilet and allow the tank to fill. Check to ensure that when the fill water stops, it does not continually trickle. If you reused the old seals and the water still trickles, replace the seals with new ones.

References

• Hammerzone: Repairing A Mansfield Toilet