How to Fix a Leaky Sink Faucet

• Locate the hot and cold shut-off valves under the sink
• Turn both valves clockwise until fully closed
• Turn on the faucet to release remaining pressure
• Cover the drain with a stopper or cloth to prevent losing screws or small parts
• Place a towel or bucket underneath to catch drips
• Kitchen faucets may have additional connections for pull-down or pull-out sprayers

Check that all lines are depressurized before continuing.

• Use a screwdriver or Allen key to loosen the small screw that holds the handle in place
• Gently lift off the handle and set it aside
• Remove decorative caps or trim pieces if they are present
• If the handle is stuck because of mineral buildup, apply a small amount of penetrating oil, which is a thin oil that helps loosen stuck parts caused by rust or mineral deposits, and gently wiggle the handle free
• Single-handle faucets typically have one central handle controlling both hot and cold water and usually contain a single cartridge
• Double-handle faucets have separate hot and cold handles and may require repeating the process for each side

• Determine whether the faucet uses a cartridge, ceramic disc, ball, or compression valve
• Identify the faucet model or series to ensure compatible replacement parts
• Inspect internal components for visible wear, mineral buildup, or corrosion
• Bathroom faucets most commonly use cartridge or ceramic disc valves designed for lighter, lower-flow use
• Kitchen faucets may include additional components for sprayers or pull-down hoses that should be inspected during disassembly

• Carefully remove the cartridge or valve assembly
• Look for cracked or flattened O-rings, worn or broken washers, or any buildup of white mineral deposits
• Clean any debris or mineral deposits from inside the valve housing
• Look for visible damage on the cartridge such as cracks, worn seals, or clogged openings
• If it is a compression faucet, check the valve seat for wear

• Replace damaged washers, O-rings, or cartridges with compatible KOHLER parts
• Apply plumber’s tape to threaded connections that require sealing
• Make sure the new cartridge is aligned the same way as the old one
• Ensure all parts sit flat and snug so they seal correctly