A leaky laundry tub faucet can cost you plenty, up to 10,000 gallons per year, according to the U.S. Environmental Protection Agency. The faucets used in laundry and utility tubs are sometimes not the best quality and they can degrade over time faster than interior bathroom and kitchen sinks. The main part to check in a leaky laundry tub faucet is the valve stem and washer. If either of these two are broken or worn, they won't be able to hold water and your faucet will leak.
Turn off the water supply for the laundry tub faucet. This will usually be located directly beneath the faucet itself. Turn the oval or round shaped knobs clockwise to turn off the water. Open up the tap in the faucet and let any water inside run out.
Unscrew the faucet handle screw. Most laundry tubs use inexpensive faucet taps and the screws are usually in plain sight. Remove the screw. Pull straight up on the handle and pull it off the valve stem.
Examine the valve stem. There are two hexagonal nuts in place. The first is the packing nut. Remove this with the wrench. Remove the second hexagonal nut, which is part of the valve stem. The whole valve stem assembly with rotate. Pull this out.
Examine the valve stem. Replace if it is cracked or worn. Turn the stem upside down to examine the washer at the bottom. This should be replaced if it is torn or in otherwise bad shape. Unscrew the retention screw. Remove the washer. Replace with a new one. Secure with the screw.
Apply pipe thread compound to the threads on the valve stem. Insert this into the socket. Tighten with the wrench. Squeeze a few drops of silicone grease onto the valve stem. Slip the packing nut over the stem and tighten.
Replace the faucet handle. Insert the screw and tighten.