How to Replace a Leaky Faucet Washer

Faucets are workhorses that inevitably succumb to friction and mineral buildup. A persistent drip isn't just an annoyance that keeps you awake at night; it is a clear signal that the internal rubber washer, which creates the watertight seal against the valve seat, has worn down or hardened. Ignoring the drip leads to higher water bills and potential pitting of the sink finish. Repairing a compression faucet is one of the most rewarding DIY tasks because it requires minimal tools and yields immediate results. When done well, the handle operates with a smooth, consistent tension and the spout remains completely dry when turned off. You are essentially resetting the clock on the fixture's lifespan with a part that costs pennies.

1. Kill the Water Flow First. Locate the shut-off valves under the bathroom sink and turn them clockwise until tight. Open the faucet handle to drain the remaining water in the lines and confirm the flow has stopped completely.
2. Expose the Valve Stem. Pry off the decorative cap on top of the handle using a flathead screwdriver. Unscrew the handle screw underneath, then pull the handle straight up and off to reveal the valve stem.
3. Pull the Stem Out. Use an adjustable wrench to loosen the packing nut on the valve stem. Once loose, unscrew the stem by hand or with the wrench and lift it out of the faucet body.
4. Swap the Worn Washer. Locate the rubber washer at the base of the stem, held in place by a small brass screw. Remove the screw, slide off the old washer, and install a matching new one.
5. Smooth the Valve Seat. Look inside the faucet body for the valve seat where the washer rests. If it looks rough or pitted, use a seat dressing tool to smooth it out, or replace it entirely.
6. Put It Back Together. Thread the valve stem back into the faucet body, tighten the packing nut, and reattach the handle. Slowly turn the water supply back on and check for leaks.