Fix a Leaky Bathroom Faucet

Leaky bathroom faucets are one of those small problems that turns expensive if you ignore it. That persistent drip isn't just annoying—it wastes water, drives up your bill, and the constant moisture accelerates corrosion inside the fixture itself. The good news is that most leaks happen for the same reason: the internal seals wear out, and they're designed to be replaced. Whether water drips from the spout, leaks under the handles, or seeps from the base, the fix follows the same logic: shut off the water, take apart the faucet, swap the bad parts, and reassemble. This guide covers the most common bathroom faucet types. What makes this repair manageable is that you're not replacing the whole faucet—you're just replacing the internal guts that wear out naturally.

1. Stop Water Before Starting. Locate the shutoff valves under the sink—there should be two, one for hot water and one for cold. Turn both valves clockwise until they stop. If there are no individual shutoff valves under the sink, you'll need to shut off the main water supply to the house. Once the valves are closed, turn on the faucet and let any remaining water drain out.
2. Pop the Handle Free. Look for a small set screw on the handle. On most bathroom faucets, this screw is hidden under a decorative cap or plug at the base of the handle. Pry that cap off gently with a flathead screwdriver, then unscrew the set screw. Once the screw is out, the handle should pull straight up and off the faucet body.
3. Expose the Valve Core. Under the handle, you'll see a decorative collar (called an escutcheon) and below that a larger hex nut (the packing nut) that holds the valve body to the faucet. Use a wrench to turn the packing nut counterclockwise and unscrew it. The escutcheon may slide off with it or stay in place—either way is fine. Set both pieces aside.
4. Pull Out the Heart. This step depends on your faucet type. If you have a compression faucet, you'll see a spindle (stem) inside that you unscrew by hand or with pliers. If you have a cartridge faucet, there's a plastic or metal cylinder that simply pulls straight out. If you have a ball faucet, you'll see a slotted collar and a cam—loosen the collar with a wrench and remove the cam, then the ball and springs come out. Lay out all these parts in order on a clean surface.
5. Swap the Worn Seals. If you removed a compression stem, unscrew the brass stem cap at the bottom and replace the rubber washer underneath it. You'll likely see a small seat (a metal cone) that may also be worn—if it's pitted or rough, replace it too using a seat wrench tool. If you removed a cartridge or ball assembly, these typically come as complete units—do not attempt to disassemble them. Buy a new cartridge or ball valve kit from the hardware store using the faucet brand and model number, then insert the new part.
6. Polish the Valve Seat. Once you've removed the stem or cartridge, the valve seat is exposed at the bottom of the faucet body. Use a valve seat wrench (a specialized tool that looks like a small socket) or very fine sandpaper to gently clean any mineral deposits or corrosion from the seat surface. The seat should feel smooth and look shiny—if it's pitted beyond light cleaning, you'll need to replace it with a new seat (this requires a seat wrench tool, also available at hardware stores).
7. Seat the New Part. Insert the new or refurbished stem, cartridge, or ball assembly back into the valve body, oriented exactly as it came out. If you have a compression faucet, screw the stem down hand-tight, then turn it gently by hand to verify it moves smoothly in both directions. If you have a cartridge faucet, slide the cartridge in until it seats fully. If you have a ball faucet, insert the cam and tighten the collar. Do not overtighten—snug is enough.
8. Lock It Down Lightly. Slide the decorative escutcheon back over the valve body, then use a wrench to thread the packing nut back on. Tighten it snugly but not aggressively—you want to stop water from leaking around the base, but overtightening can damage the seal and make the handle hard to turn. The wrench should require firm hand pressure, not your full body weight.
9. Reattach the Handle. Slide the handle back onto the stem or cartridge. Align it so it points down when the faucet is off and straight up when fully on (or whatever the original orientation was—use that reference photo). Once aligned, insert the set screw and tighten it hand-tight with a screwdriver. Snap the decorative cap back over the screw.
10. Restore the Water Flow. Slowly turn both shutoff valves back on (counterclockwise). Turn them gently at first so you don't get a sudden water hammer shock through the lines. Once both are fully open, turn on the faucet and let water run for 10 seconds to flush any debris from the supply lines.
11. Verify the Repair Works. Turn the handle on and off several times in both hot and cold directions. The faucet should move smoothly and water should flow without any dripping once you've turned it off. Place a dry rag under the faucet where the handle meets the body and under the sink at the supply line connections. Wait 15 minutes with the rag in place, then inspect it—it should still be dry. If you see any moisture, tighten the appropriate connection or check the packing nut.
12. Finish and Store Tools. Old faucet parts made of brass and metal can usually go in the trash. Rubber washers and seals are not recyclable in most communities. Wipe down under the sink with a dry cloth and put all tools away. Run the faucet for 30 seconds to rinse any debris from the interior before you consider the job done.