How to Fix a Leaking Kitchen Sink

Water underneath your kitchen sink is rarely a mystery; it is almost always a failure of connection. When pipes start to weep, it is usually because the slip-joint nuts have vibrated loose over time or the rubber washers inside the joints have hardened and lost their seal. A dry cabinet is the goal, and achieving it is simply a matter of isolating the leak and restoring the integrity of the mechanical connection. Done well, this repair takes less time than a trip to the hardware store. The secret is to resist the urge to overtighten everything. Overtightening cracks plastic pipes and distorts rubber gaskets, which creates a new leak in place of the old one. Work methodically, keep a bucket handy, and trust that a firm, hand-tightened connection is usually all that is required to stop the drip.

1. Clear the cabinet first. Empty all cleaning supplies and boxes from under the sink. Place a bucket or a large shallow pan directly beneath the suspected leak to catch any residual water.
2. Find the exact source. Wipe all pipes completely dry with a rag. Run the faucet for a minute and watch the joints closely to see exactly which nut or pipe segment is weeping.
3. Tighten gently, never force. If a slip-joint nut is loose, try tightening it by hand in a clockwise direction. If it refuses to budge, use channel-lock pliers to give it no more than a quarter-turn.
4. Disassemble the joint. If tightening fails, unscrew the slip-joint nut completely. Pull the pipe segment away to inspect the rubber washer and the mating surfaces for debris or damage.
5. Swap the worn washer. Slide the old washer off and replace it with a new one of the exact same size. Ensure the tapered side of the washer faces the direction of the joint connection.
6. Verify the seal holds. Realign the pipes, slide the nut into place, and tighten it firmly by hand. Run the water for two minutes to confirm the leak is gone.