The conventional float ball, attached by a metal or plastic arm to a ballcock, was the standard fill valve in toilets for years. The position of the float ball determines the amount of water that will refill the tank. A float ball in need of repair will cause your toilet to run nonstop, allowing water to constantly flow into the tank through the ballcock, until the high water level spills over into the overflow tube. The proper water level should be set approximately 1 inch below the top of the overflow tube. Repairing the float ball involves following simple steps.
Place a towel on the floor beside the toilet. Remove the tank lid and carefully set the lid onto the towel. Compare the water level to the tank's water level mark, or the mark on the overflow tube. Determine if the water level is so high that it runs down the overflow tube. Follow the arm that connects to the float ball, and locate the screw that attaches the arm to the ballcock. Adjust this screw, using a screwdriver, to lower the float ball. Flush the toilet and observe the tank's water level after it refills.
Remove the float arm from the ballcock, using the screwdriver, to prevent damaging the ballcock. Bend the arm gently downward. Do this if the connecting screw has been adjusted to its maximum and the float ball still needs to be lowered. This will increase pressure on the valve and turn off the constant flow of water. Reattach the arm to the ballcock and flush the toilet, checking the water level.
Turn the shutoff valve completely clockwise to shut off the flow of water into the tank. Unscrew a damaged float ball that does not float on top of the water or rise high enough to shut off the ballcock. Turn the float ball counterclockwise to remove it. Grip the float arm with pliers, if necessary, while removing the float ball. Shake the float ball to determine if water is inside it.
Apply either plumber's tape or petroleum jelly to the threads, and screw the replacement float ball onto the float arm. Turn the water shutoff valve counterclockwise to turn on the water to the tank. Flush the toilet and examine the water level after the tank refills. Adjust the connecting screw to adjust the float arm, as necessary, to raise or lower the water level.