Many do-it-yourselfers shy away from plumbing problems. The fear is that attempting a fix could make the problem worse. However, with the proper tools and some basic knowledge, simple plumbing repairs are doable for the average homeowner. One such job is the leaky water shutoff valve. These valves, most commonly found behind toilets and under sinks, develop leaks over time. Usually they do not need replacement--just simple tightening and readjustment.
Grip the packing nut behind the shutoff valve's handle and twist it clockwise about 1/4 turn, using the pliers. Sometimes this will stop a small leak.
Search for the main water shutoff valve for the home, floor or room. This valve usually is in the basement or a utility closet and it will be clearly labeled. Turn on all the faucets and flush all the toilets associated with the main shutoff valve to empty the pipes of water. Place a bucket or a thick towel on the floor under the leaky valve just in case some residual water leaks out during work.
Remove the screw in the center of the shutoff valve handle, using a screwdriver. Remove the packing nut by twisting counterclockwise with the pliers. This will provide access to the threaded stem. Pull this out slowly, noting the position of the washers.
Clean off the washers, removing any buildup or deposits. Soak the washer in water and message it to regain any lost flexibility.
Reassemble the valve. Tighten with the pliers and screwdriver. Turn the water back on and test the valve.