Vent, Valve & Volt
Bathroom sink stopper won't hold water

You can fix this

Likely cause: a broken or corroded pivot rod

If the rod under the sink is snapped, rusted through, or moves without moving the stopper, the rod is the problem. Replace it with one that matches.

Why this happens

Moen lists a broken pivot rod as one of the two typical causes of a pop-up drain that will not close or open properly, and says a broken rod needs to be replaced. This Old House describes the internal pivot piece corroding or snapping off entirely as a common failure point on older pop-up assemblies. When that happens the lift rod still moves, but nothing moves the stopper.

How to fix it

  1. Has a chemical drain cleaner gone down this sink? Then do not open the drain. Family Handyman says leftover caustic chemicals are a danger to anyone who takes the trap apart. Call a plumber and say what you used. If not, let any water in the sink drain away, or bail it out. Close both stops under the sink so the faucet cannot be run while the drain is open, and set a pan or bucket under the drain pipes, as This Old House advises. If a stop will not turn, do not force it. Leave the faucet off instead.
  2. Squeeze the spring clip and slide the pivot rod out of the strap.
  3. Unscrew the pivot rod nut on the back of the drain. Moen says it is metal or gray plastic, depending on the model. Danco notes there may be washers inside the nut, so save them.
  4. Pull the rod out and look at it. If it is whole and clean, it may simply have missed the stopper, so go to the next step. If it is snapped or rusted through, replace it with a rod that matches. Bob Vila says replacement parts have to be compatible with your existing stopper system, and Pfister says your faucet model's parts diagram gives the correct part number.
  5. Turn the stopper so its hole or tab faces the back of the sink, then slide the rod in so it catches the stopper. Pfister says to wiggle the rod up and down to confirm the stopper moves with it.
  6. Thread the nut back on until it is snug and the rod still moves freely, then clip the rod to the strap.
  7. Open the stops, pull the lift rod up and fill the sink. Check that the water holds and the nut stays dry.

When to stop. If the nut will not come off, the drain body itself is rusted, or a pedestal keeps you from reaching the nut, stop and call a plumber. A master plumber quoted by Family Handyman says a fully rusted pop-up has to be cut out and replaced.

If this does not fix it, tell the plumber

  • The pivot rod is broken or rusted, or it moves without moving the stopper.
  • Whether the nut on the back of the drain came off cleanly.
  • Whether the drain pipe around the nut looks rusted too.
  • The faucet brand and model, if you know it.

Build the full list: what to tell the plumber.

Start this troubleshooter over

References (every fact above comes from one of these pages)
  1. Moen: Pop-up drain assembly not closing or opening properly
  2. This Old House: How to fix a bath sink stopper
  3. Danco: Instructions for universal pop-up stoppers
  4. Pfister: My pop up drain is not draining water (includes does not hold water and leaking under sink)
  5. Bob Vila: How to fix a bathroom sink stopper
  6. Family Handyman: How to remove a stopper from the bathroom sink
  7. Family Handyman: How to clear clogged drains

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