How to Replace a Kitchen Faucet Cartridge
Stop a dripping kitchen faucet handle by shutting off water lines, removing the handle and bonnet nut, and replacing the worn ceramic cartridge valve.
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🧰 Required Tools & Equipment
- ✓ Hex key set (Allen wrench)
- ✓ Adjustable wrench
- ✓ Small flathead screwdriver
- ✓ Clean microfiber rag
- ✓ Flashlight
📦 Materials & Supplies
- ✓ OEM replacement faucet cartridge
- ✓ Food-grade silicone plumber's grease
- ✓ White vinegar (for mineral cleanup)
⚠️ Safety Checkpoints & Warnings
- • Ensure both hot and cold shutoff valves beneath the sink are turned completely off before loosening any hardware.
- • Place a rag over the sink drain opening immediately so small screws and decorative caps cannot fall down the pipe.
- • Open the faucet handle fully to bleed remaining water pressure before attempting cartridge removal.
📋 Step-by-Step Guide (7 Steps)
Shut Off Water Supply and Cover Drain
Locate the hot and cold shutoff valves inside the cabinet below the sink and rotate them clockwise until firmly closed. Turn on the faucet handle to bleed out all residual line pressure and verify water has completely stopped flowing. Cover the sink drain basin with a dry towel.
- • Shutoff valves turned perpendicular/fully clockwise.
- • Zero water drips exiting the faucet spout when handle is in full-on position.
- • Sink drain covered completely by a towel.
- • Forgetting to relieve residual pressure before disassembling the faucet body.
- • Leaving the drain open, allowing tiny set screws to drop down the P-trap.
Remove Handle Plug and Set Screw
Use the edge of a small flathead screwdriver to gently pry off the decorative index button or rubber plug concealing the handle screw. Insert the correctly sized hex key into the exposed recess and turn counterclockwise 3 to 4 full turns to loosen the set screw.
- • Decorative cap resting safely on the counter.
- • Hex key inserted straight into the handle opening without slipping.
- • Using the wrong hex key size and stripping the internal socket.
- • Backing the set screw all the way out until it drops and gets lost.
Remove Handle and Dome Bonnet Collar
Pull the faucet handle straight upward off the cartridge stem. Unscrew the decorative dome-shaped bonnet cap by hand in a counterclockwise direction; wrap a cloth around it for extra grip if mineral deposits make it stubborn.
- • Faucet handle completely separated from the faucet body.
- • Smooth brass or plastic cartridge nut fully visible with the dome cap removed.
- • Using bare metal pliers on the smooth decorative dome, which crushes and scratches the finish.
- • Wiggling the handle with violent side-to-side force, which can snap the plastic cartridge stem.
Unscrew Cartridge Retaining Nut
Fit an adjustable wrench securely across the flat edges of the brass cartridge retaining nut. Hold the faucet base steady with one hand while turning the wrench counterclockwise to loosen and unthread the nut.
- • Brass retaining nut completely unthreaded and removed.
- • Top rim of the cartridge exposed inside the faucet cavity.
- • Allowing the wrench jaws to slip off the thin brass flats, rounding the nut corners.
- • Letting the entire faucet body rotate on the countertop during heavy wrenching.
Extract Old Cartridge and Clean Valve Body
Grasp the cartridge stem and pull straight up to remove the valve; use pliers on the plastic stem if tightly seated. Inspect the interior cavity with a flashlight and wipe away all debris, grit, and scale using a rag dipped in white vinegar.
- • Empty brass valve chamber completely clean and free of black rubber flakes or lime.
- • Old cartridge fully removed on the counter.
- • Leaving old degraded rubber seals or loose fragments stuck inside the bottom of the housing.
- • Prying aggressively against the brass inner walls, causing gouges that prevent a watertight seal.
Install New Cartridge and Align Index Tabs
Apply a thin film of food-grade silicone grease to the cartridge O-rings. Lower the new cartridge into the valve body, rotating it slightly until the indexing alignment tabs on the cartridge drop fully into the matching notches inside the brass casing.
- • Cartridge sitting completely flat and flush inside the faucet housing without rocking.
- • Alignment tabs securely locked into the casing notches.
- • Forcing the cartridge down when tabs are misaligned, which snaps the locator pins.
- • Using petroleum-based grease (like Vaseline) which degrades rubber O-rings.
Reassemble Hardware and Test for Leaks
Thread the retaining nut back on by hand and snug it down firmly with the wrench without overtightening. Thread the dome collar back on, slide the handle onto the stem, tighten the set screw, replace the plug, and slowly restore the water supply to verify leak-free operation.
- • Bonnet nut snug, handle secure with no wobble, and index cap in place.
- • Water running smoothly from spout with zero seepage around handle base when turned off.
- • Overtightening the retaining nut, which makes the handle stiff and hard to turn.
- • Turning water shutoff valves on at maximum speed, creating water hammer.
Credit: inspired by an original tutorial by KOHLER — watch the original on YouTube.
Don’t have everything?
- No Food-grade silicone plumber's grease? Clean water (as temporary lube for O-rings, never use petroleum jelly)
- No Hex key set (Allen wrench)? Correctly sized Torx (star) bit attached to a precision driver handle