How to Repair a Leaky Sink Faucet

Faucets are workhorses that eventually give in to the constant pressure of your home's water system. A steady drip isn't just an annoying sound that keeps you awake at night; it is a signal that internal seals are failing and wasting precious gallons of water. When you fix a leak early, you prevent internal corrosion from turning a simple part replacement into a full faucet installation. Done well, a repair restores the smooth, silent operation of your handle and stops the leak immediately. You do not need to be a professional plumber to handle this, provided you work methodically and keep your parts organized. Treat this as a straightforward mechanical swap, and you will have your sink back in working order by the end of the afternoon.

1. Kill the Water Supply First. Locate the shut-off valves under the sink and turn them clockwise until they are tight. Turn on the faucet to drain any remaining pressure and water from the lines.
2. Expose the Inner Cartridge. Use an Allen wrench to loosen the small set screw on the side or back of the handle. Pull the handle firmly upward to expose the faucet cartridge or stem.
3. Loosen the Bonnet Nut Gently. Using an adjustable wrench, unscrew the decorative bonnet nut or retaining nut. Be gentle to avoid scratching the finish, and use a cloth between the wrench and the nut if necessary.
4. Remove the Worn Cartridge. Pull the old cartridge straight out of the faucet body using pliers if it is stuck. Note the orientation of the cartridge so you know exactly how the replacement should sit.
5. Install Fresh Seals or Cartridge. Inspect the rubber O-rings for cuts or flattened edges. Either replace the specific O-rings or swap in a new, identical cartridge assembly.
6. Reassemble and Check for Leaks. Slide the cartridge back into place, tighten the bonnet nut, and replace the handle. Slowly turn the water valves back on and check for leaks while running the faucet.