While most indoor faucets now use cartridge-style mechanisms, outdoor faucets (called hose bibs), generally use an older, compression-style design. These faucets control water by means of a threaded stem with a rubber or neoprene washer on the end, which presses down against an opening in a metal valve seat to stop the flow of water. The handle of the faucet is attached to the inner stem, and it serves to lift and lower the stem to open and close the flow of water. Water is prevented from seeping up around the stem and out around the handle by several wrappings of waterproof packing string underneath the packing nut.
Fixing a leaky hose bib almost always involves one (or both) of two things:
- Replacing the compression washer at the end of the inner valve stem. This will allow the stem to fully close down against the valve seat, keeping the hose bib from constantly dripping.
- Replacing the packing string that is wrapped around the valve stem under the packing nut. This will prevent water from seeping up around the handle each time you use the faucet.
Most leaky hose bibs will be solved by one or both of these solutions, but it is possible that very old faucets may have cracks to the body of the faucet or serious damage to the valve seat, requiring that you replace the entire hose bib.
Tools and Supplies You Will Need
- Channel-lock pliers or adjustable wrench
- Faucet washer assortment
- Graphite packing string, or bonnet washer
It's generally easiest to address both possible causes of leaking when servicing a hose bib—the stem washer and the handle packing string.
Shut Off the Water
Begin by shutting off the water to the hose bib. Usually, you will find a shutoff valve inside the house, controlling the water flow to the outdoor hose bib. Close this valve by turning the handle fully in the clockwise direction. If your hose bib does not have a shutoff valve, you can shut off the water supply to the entire house.
Remove the Handle
Use a screwdriver to remove the screw that holds the handle of the hose bib to the valve stem, then pull the handle off—a bit of wiggling may be required. Carefully set the handle and screw aside.
Unscrew the Packing Nut
Next, use a channel-lock pliers or adjustable wrench to unscrew the packing nut (sometimes called a bonnet nut) that secures the valve stem to the faucet body.
Remove the Valve Stem
Remove the valve stem from the faucet body. Usually this involves unscrewing the stem from the threaded body of the faucet; on some types, unscrewing it may require turning the stem in a clockwise direction rather than in the traditional counterclockwise fashion.
Replace the Stem Washer
Inspect the rubber or neoprene washer at the end of the valve stem. If it is hardened, cracked, or deformed, this is very likely the cause of your leaky faucet. Unscrew the brass screw holding the washer in place on the stem. Brass is a soft metal, so use care when unscrewing it. If the screw gets damaged, you may need to replace it—washer kits often come with replacement screws.
Choose an exact replacement for the old washer and and attach it to the end of the valve stem with a screw.
Replace the Packing String
Unwrap the old graphite or Teflon packing string from around the valve stem beneath the packing nut, then wrap several loops of new strong around the stem in a clockwise direction (as you look down at the stem from above). Alternately, you can use a fiber packing washer, which serves the same function as packing string. Larger washer kits usually include an assortment of packing washers.
Reassemble the Faucet
Thread the valve stem back into the body of the faucet, then thread the packing nut onto the top of the faucet. Tighten the packing nut slightly with a wrench, then put the faucet handle back onto the stem and check the operation of the faucet. Tightening the packing nut too much may make the handle hard to turn. The handle should turn freely, and you should be able to feel the washer compress down against the valve seat inside the faucet.
Test the Faucet
Turn the water back on and check the operation of the faucet, inspecting for leaks. If you experience any leaking around the handle, slightly tighten the packing nut a little further.