How To Fix a Leaky Faucet
Before working on your faucet, turn off the water at the shut off valves or the main shut off, close the drain so you won't lose small parts and put a towel in the sink to prevent damage from dropped parts or tools. Wear a helmet if you are really clumsy.
Caution: Please read our safety information before attempting any testing, maintenance or repairs.
A leaky faucet typically leaks from the spout or the knobs. If your faucet is leaking from the spout, continue reading this article. Otherwise, refer to our diagnostic page for links to the appropriate article.
There are four common operating styles of faucets; compression, cartridge, ceramic disc and ball. If your faucet has two handles, then it is probably a compression type faucet, although it could be cartridge or disc. This articledeals with the compression style faucet only. Refer to our diagnostic page for links to other styles of faucets.
How to Fix a Compression Faucet
A compression faucet has two handles and as you turn the handle it opens a gap between the valve seat and a washer letting water through. As that washer ages it may harden or become worn and will fail to make a tight seal with the valve seat. This allows water to leak through. In some cases the valve seat itself may become damaged or worn and it causes water to leak. Both conditions can usually be easily repaired.
To determine which handle is leaking, alternately turn off the hot and cold water at the supply valve under the sink. When the leaking stops, you know which valve is leaking. However, it may be wise to repair both valves, since they are probably both well worn.
With the water turned off, remove the decorative cap from the knob. Place the parts in order of disassembly to aid in reassembly. The cap may pry off or unscrew. Use a small screwdriver or putty knife wrapped with tape to reduce the risk of scratching the surface. If the cap is designed to unscrew, it will unscrew in the direction opposite that the knob turns. Next, remove the screw that holds the knob in place and lift off the knob (and sleeve if any).
Next you must remove the packing nut. Use pliers or a wrench and turn the nut counterclockwise. Lift the stem out, turning it counterclockwise a few turns if necessary.
What you see now is the valve stem. At the end of the valve stem you will find a rubber washer fastened with a brass screw. That washer should be smooth, flat and flexible. Replacing the seat washer is simple, remove the screw that secures it, replace the washer with an identical new washer and replace the screw.
Inside the faucet body is the valve seat. While the valve stem is out, inspect the valve seat with your fingertip; it should feel smooth. If you cannot reach it, use a flashlight and visually inspect the seat. If you see or feel pits or irregulaties, then it must also be repaired or replaced.
If the valve seat has a square or hexagonal hole in the center it can be removed with a seat wrench.
Unscrew the valve seat and replace it with an identical part. If the valve seat has a round hole, it cannot be replaced but it can be smoothed with an inexpensive seat dressing tool.
Follow the steps backward to reassemble the faucet and finish the repair.