If you mean it continues to fill when you're trying to do a load of clothes, then it's not the fill valve. There's a tube from the bottom of the tub up to a bellows pressure switch behind the water level selector buttons. With the washer empty, try connecting a hose from a manual tire pump to the switch, then at about 2-5 psi the machine should stop filling and start agitating. If it doesn't, the switch is bad, if it does, then the hose to the bottom of the tub is leaking so the air pressure (hence water level) is never sensed. Also, the switch must hold the air pressure and not leak down -- if it does then the switch is the source of the leak.
Andy, October 2007