Stop Drip at Toilet Water Shut Off Valve Seal Gasket

Stop dripping at the toilet water shut off by fixing the seal gasket, washer or packing. Toilet shut off valves start to drip over time due to loose packing nuts on these valves. This may be caused by drying or mineral deposits on the washers. The leaking shut-off valve doesn’t mean it has to be replaced

First check the packing nut. Under the valve handle is the small nut that tightens packing against the stem. The packing is a graphite or compressive material, or washer.

Just by turning on the handle, the packing seal may begin to leak. Tightening the nut 1/8 to 1/4 turn usually will stop dripping from the stem on the handle. Don’t remove the valve, just tighten the packing nut. Hopefully this is enough to compress the packing so that it is sealed on the valve stem to prevent water leaks.

If this works, check the toilet water shut off seal gasket the next day. If it still leaks, you will have to replace the packing or the valve.

The water supply shut off valves drip or leak behind toilets and under sinks because they corrode and stick since they are rarely used. The neoprene washers become brittle and encrusted with mineral deposits leading to loss of sealing.

Wrap tape or cloth around the pliers to not scratch the nut or porcelain.