The moving part in the valve is usually a brass cylinder with a rubber washer mounted in one end. Turn off the water, remove the split pin pivot from the valve, remove the float arm, and extract the plunger. New washers can be got from builders' merchants. The end of the plunger unscrews (although you often can't see the join) and the washer can be replaced. Look at the nozzle which the
plunger acts on. If it is corroded, it may be replaceable
plastic. If not you need a new valve.
Tony, March 2009
