Evidence grade: B1 — Trade practice
A drip means a seal has failed — nothing more mysterious. A worn seat washer or spring in a rotary-ball faucet, a tired cartridge or O-ring in a cartridge faucet, a worn rubber seal in a ceramic-disc faucet. The fix is: find where the water is escaping, shut off the supply, disassemble, and replace the worn seal. Cartridges and seal kits are inexpensive and made to be replaced.
Effort: Moderate · about 1 hr · Allen wrenches, screwdrivers, slip-joint pliers, plumber's grease, replacement cartridge or seals
Step 0 (all faucets): find the leak, kill the water, protect the drain
- Locate the leak. Drip from the end of the spout is a seal failure; water leaking around the base of the handle is an O-ring or packing failure; water pooling at the base of the spout is worn spout O-rings — each needs different parts [1].
- Turn off the supply — the shutoff valves under the sink; if they do not work or do not exist, close the house main. Then open the faucet in the center position to relieve pressure and confirm the water is actually off [1].
- Cover the drain with a rag or strainer basket — small parts love to fall in.
- Record part order as you go. A phone photo of each stage saves reassembly; set parts aside in the order removed [1].
Ball faucets (single lever, rotating ball — common Delta/Peerless)
- Leak at the handle base: try tightening the adjusting ring clockwise with the kit's spanner tool first [1].
- Drip from the spout: replace the seats and springs — drop the springs into the recesses, press the rubber seats over them with a fingertip, minding the tapered spring orientation [1].
- A full repair kit (ball, springs, seats, spout O-rings) covers nearly any repair on these and is cheap.
Cartridge faucets (many Moen and others)
Remove the handle, unscrew the retainer nut, and pull the cartridge straight out — note its orientation to the notches so the new one goes in the same way. To stop spout drips, either replace the O-rings on the cartridge if they are worn or replace the whole cartridge; leaking around the handles means the cartridge O-rings are bad. Take the old cartridge to the store to match the replacement [1].
Ceramic-disc faucets
These rarely need fixing, but when they drip it is usually the rubber seals under the disc cartridge — replace those first and reassemble, and only then consider a whole replacement cartridge, which is the expensive part [1]. Leave the faucet open while turning the water back on so trapped air escapes without slamming the discs [1].
Spout-base leaks
Pull the spout up and off (it may be stubborn), slide the old O-rings out of their grooves, install new ones lubricated with plumber's grease, and reinstall [1].
Stop rules — call a plumber NOW if
- The under-sink shutoff valves will not fully stop the water. Do not disassemble a faucet with live supply. Use the house main — and if the main does not hold either, this is now a plumber's job before it is a faucet job.
- A nut or cartridge will not move with reasonable force. A corroded faucet body can crack before the nut turns — and a cracked body means a new faucet. If you find yourself reefing on it, stop.
- The drip persists after the correct parts are replaced. The valve body or seats may be damaged beyond seal replacement.
- You do not know where your main water shutoff is — find it before starting any plumbing work, or do not start.
PPE and ventilation
No special PPE is needed. Gloves are optional for comfort; eye protection is sensible when prying at stubborn clips under a sink, but not required. Ventilation is not a factor.
Honest limits
- This article covers modern single-lever ball, cartridge, and ceramic-disc faucets. Older two-handle compression faucets work on the same principle — a rubber seat washer on the stem — but the parts and stems differ; the same shutoff and parts-matching rules apply.
- Faucet brands vary enormously; if the model name is not stamped on the body, the old part in your hand is the only reliable key to the right replacement [1].
- Before reassembly, crack the shutoff open slightly with a rag held over the faucet to flush out loosened debris — then reassemble [1].
Sources
- Family Handyman (via The Free Library) — "Stop faucet drips: you can fix almost any drippy single-lever kitchen faucet in about an hour" (consultants: master plumbers) — https://www.thefreelibrary.com/Stop+faucet+drips%3A+you+can+fix+almost+any+drippy+single-lever+kitchen...-a0118807426
Repair Lab · Release 1 · Evidence last checked September 30, 2026 · A project of AOJEL