How to Fix a Leaking Bathroom Faucet

Faucets are workhorses that eventually give up the fight against mineral buildup and rubber degradation. That steady drip-drip-drip is more than just an annoyance; it is a waste of water that can stain your sink basin and prematurely wear out your drain stopper or pop-up assembly. Fixing a faucet is a rite of passage for every homeowner. By replacing the internal components, you extend the life of your fixture by years and save yourself the high cost of a professional plumber call-out. You are simply removing the handle, extracting the cartridge or stem, and swapping out the failing rubber bits. Work methodically, keep your parts organized, and your faucet will stop leaking before the hour is up.

1. Stop the flow first. Locate the shut-off valves under the sink and turn them clockwise until they stop. Open the faucet handles to drain the remaining water in the lines and relieve pressure.
2. Expose the cartridge. Pry off the decorative cap on the handle using a flathead screwdriver. Use an Allen wrench or a small screwdriver to loosen the set screw hidden underneath, then pull the handle off the valve stem.
3. Pull the cartridge out. Use an adjustable wrench to unscrew the packing nut or bonnet that holds the cartridge in place. Pull the cartridge or valve stem straight out using needle-nose pliers.
4. Match your seals exactly. Examine the rubber O-rings and seats for cracks or flattening. Bring the old cartridge or the removed rubber rings to the hardware store to ensure an exact match for the replacements.
5. Slide the new cartridge in. Slide the new cartridge or refreshed stem assembly back into the faucet body. Tighten the packing nut firmly with your wrench, but do not overtighten as this can crack the housing.
6. Verify the seal holds. Replace the faucet handle and tighten the set screw. Slowly turn the water supply valves back on and check for leaks around the base of the handle.