How to Replace a Faucet Cartridge

Faucets are workhorses that inevitably succumb to the friction of daily use, usually manifesting as that maddening, rhythmic drip. The culprit is almost always the cartridge, a sealed plastic or brass component that controls the flow and temperature of water within your fixture. When the internal rubber O-rings or seals degrade, water finds its way past the barrier, leading to leaks and wasted water. Fixing this is a rite of passage for any homeowner and requires more patience than raw strength. Because manufacturers change designs frequently, the key to success is keeping your workspace organized and ensuring you have the exact part in hand before you start. Once you master the mechanics of pulling the old cartridge, you can tackle almost any leak in the house.

1. Kill the water supply first. Locate the shut-off valves under the sink and turn them clockwise until they stop. Open the faucet handle to bleed out remaining pressure and ensure no water is flowing.
2. Pop off the hidden fastener. Pry off the decorative cap on the handle to reveal the screw hidden underneath. Use an Allen wrench or screwdriver to loosen the screw and pull the handle straight off the stem.
3. Loosen the cartridge collar. Use an adjustable wrench to loosen the bonnet nut holding the cartridge in place. Turn counter-clockwise carefully to avoid marring the metal finish.
4. Document before you extract. Grip the top of the cartridge with pliers and pull it straight up. Some cartridges require a specific puller tool if they are heavily calcified inside the valve body.
5. Seat the replacement cartridge. Clean any debris or mineral deposits from the inside of the faucet body with a cloth. Slide the new cartridge into place, ensuring the alignment tabs match the slots in the valve.
6. Test for silent operation. Screw the bonnet nut back on, tighten it, and reattach the handle. Slowly turn your water valves back on and check the faucet for leaks.