How to Fix a Dripping Bathroom Faucet

Most dripping faucets need either a new washer, O-ring, or cartridge replacement, depending on your faucet type.

1. Kill the Water Flow First. Locate the shut-off valves under the sink and turn them clockwise until tight. If you can't find individual valves, shut off the main water supply to your home. Turn on the faucet to drain any remaining water in the lines.
2. Expose the Hidden Hardware. Look for a screw on top of or behind the handle. Remove this screw with a screwdriver. If there's no visible screw, check for a decorative cap that pops off to reveal the screw underneath. Pull the handle straight up or wiggle it gently while pulling to remove it.
3. Know Your Enemy Type. Look at what's exposed after removing the handle. You'll see either a packing nut (compression faucet), a cartridge sleeve (cartridge faucet), a rounded cap (ball faucet), or ceramic discs (disc faucet). This determines which parts you'll need to replace.
4. Swap Out the Seal. Use an adjustable wrench to remove the packing nut. Pull out the stem assembly. At the bottom, you'll find a rubber washer held by a brass screw. Replace both the washer and screw with exact matches from the hardware store. Also replace the O-ring around the stem if it looks cracked or worn.
5. Install the New Cartridge. Remove the retaining clip or nut holding the cartridge in place. Pull the cartridge straight out with pliers, noting its orientation. Take the old cartridge to the hardware store to get an exact replacement. Insert the new cartridge in the same position and secure with the retaining hardware.
6. Replace the Ball Assembly. Remove the cap and collar with pliers. Lift out the ball and inspect the rubber seats and springs underneath. Replace worn seats and springs as a set. Clean the ball and reassemble, making sure the ball's alignment pin fits into the proper slot.
7. Refresh the Disc Cartridge. Remove the mounting screws holding the cartridge. Lift out the entire cartridge assembly. Clean any mineral deposits from the valve seat with white vinegar. Install a new cartridge, ensuring proper alignment with the hot and cold water inlets.
8. Verify the Fix Works. Put everything back together in reverse order, hand-tightening connections first, then snugging with tools. Turn the water supply back on slowly and test the faucet. Check for leaks around all connections and adjust tightness as needed.