Outdoor faucets are built to prevent freezing and bursting under the pressure of harsh winter winds and snow. Eventually, though, a small leak may appear from the faucet that will not stop, no matter how hard you tighten the water control knob. A leaking faucet likely has a faulty valve stem. The valve stem is a long tube, about 12 inches, that goes down the water pipe leading from your water supply. If it is corroded, the water will not shut off properly.
Turn off the water supply to your outdoor faucet.
Remove the screw holding the water control knob in place with a screwdriver then pull the knob off.
Hold the faucet with a wrench and grasp the packing nut with another wrench. Turn the packing nut counterclockwise to remove it from the faucet.
Place the knob back onto the end of the valve stem and turn it counterclockwise to remove the stem from the faucet. Pull it out of the faucet slowly.
Slide in a new valve stem and attach the knob. Tighten down the screw and the packing nut until the valve is tight. Turn on the water supply and inspect the valve for leaks.