How to Repair a Leaking Faucet Base

Identifying a Base Leak

A leak at the base of a faucet — where the faucet body meets the sink — is different from a spout drip. Base leaks typically appear as water pooling around the faucet when it is running and may go unnoticed because the water spreads across the sink surface. Dry the area around the faucet completely, then run water while watching the base closely. If water seeps out, the O-rings inside the faucet body are likely worn.

Accessing the O-Rings

Turn off the water supply valves and open the faucet to relieve pressure. Remove the faucet handle by locating the set screw (usually hidden under a decorative cap) and unscrewing it. For single-handle faucets, you may need to remove a dome cap or escutcheon to access the cartridge area. Carefully note the order of components as you disassemble — taking photos at each step helps during reassembly.

Replacing O-Rings

Inspect all O-rings on the faucet body and cartridge. Worn O-rings may appear flat, cracked, or have visible gaps. Remove old O-rings by carefully cutting them with a utility knife — do not gouge the metal surfaces beneath. Apply a thin coat of plumber's silicone grease to new O-rings before installation to help them seat properly and last longer. Use exact-size replacements — bring the old O-rings to the hardware store or order manufacturer-specific repair kits.

Reassembly and Testing

Reassemble the faucet in reverse order, ensuring each component seats properly. Hand-tighten all connections first, then use tools to snug them an additional quarter turn. Turn the water back on slowly and run the faucet at various handle positions for several minutes. Dry the base area and wait 10 minutes while the faucet runs, checking for any moisture. If the leak persists, the faucet body itself may be corroded and the entire faucet should be replaced.