How to Fix or Replace a Bathroom Sink Pop-Up Stopper

A bathroom sink pop-up stopper that won't hold water or sticks in the up position is one of those fixtures that feels broken until you understand how it actually works. The stopper is connected to a pivot rod that runs through the back of your sink drain. When you push the stopper down, you're actually engaging a mechanical linkage that lives inside the wall or cabinet below. The good news is that most failures are simple fixes—you're dealing with basic mechanics, not electronics. Debris clogs the works, the rubber seal dries out, or the linkage gets slightly misaligned. You can diagnose and repair this yourself in under an hour with nothing more than basic tools. The only time you'll need a plumber is if the pivot rod itself has corroded so badly it can't be adjusted or if the pop-up assembly has failed internally.

1. Extract the Stopper Cleanly. Lift the pop-up stopper straight up out of the sink drain. If it's stuck, grab it firmly near the base and wiggle side to side while pulling upward. Most stoppers either pull straight out or unscrew from a collar at the drain entrance. Once free, hold it up to the light and inspect it for visible debris, hair, or mineral buildup.
2. Scrub Away Buildup. Use an old toothbrush or small wire brush to scrub away hair, soap scum, and mineral deposits from the stopper itself. Pay special attention to the underside and any grooves. Then lean over the sink and use a small flashlight to look down into the drain opening where the stopper sits. Remove any visible hair or debris using needle-nose pliers or a small hook. Wipe the drain seat with a damp cloth.
3. Locate the Pivot Rod. Open the cabinet or vanity below the sink. You'll see the drain pipe and, running horizontally from it, a rod with a hole at the end. This is the pivot rod. It connects to a clevis strap (a metal clip) which slides up and down a vertical rod attached to the sink faucet lift rod. Clear any visible water or debris from this area. You may need to position a small bucket underneath to catch residual water from the drain trap.
4. Free the Cotter Pin. At the end of the pivot rod (the horizontal rod), you'll see a small metal pin or clip holding it in place. This is the cotter pin. Use needle-nose pliers to gently wiggle and extract it. Don't force it; if it won't budge, apply a light spray of penetrating oil and wait two minutes. Once the pin is out, you can slide the pivot rod out of its socket in the drain assembly.
5. Check Rod Condition. Slide the pivot rod the rest of the way out and examine it for corrosion, mineral deposits, or visible damage. Scrub it clean with an old toothbrush and white vinegar if there's mineral buildup. If the rod is badly corroded or pitted, it will need replacement—you can't adjust a damaged rod. Assuming it's clean, check the rubber gasket or seal that slides over the rod. If it's cracked, dried out, or missing, note that you'll need to replace it.
6. Fine-Tune the Mechanism. Look at the clevis strap (the metal clip on the vertical rod attached to your faucet lift rod). There's a screw where the clevis connects to the lift rod. This screw controls how high or low the stopper sits in the drain. If your stopper won't stay down, turn this screw clockwise (tighten) a quarter turn. If it won't stay up or rises too slowly, turn it counterclockwise (loosen) a quarter turn. Make small adjustments; you can always turn it more if needed.
7. Reseat the Pivot Rod. Slide the clean pivot rod back into its socket in the drain assembly. It should slide in smoothly and align with the hole at the end. If it sticks or doesn't align, pull it back out and check for debris in the socket—a small amount of dried mineral deposit can block it. Once aligned, reinsert the cotter pin through the hole at the end of the rod to lock it in place. Tap the pin gently with a hammer to make sure it's seated.
8. Verify Smooth Operation. Go back to the sink and pull up on the faucet lift rod (the plunger handle). The stopper should descend into the drain smoothly and completely. Push the lift rod down and the stopper should rise. Repeat this action several times to confirm smooth operation. Fill the sink with a few inches of water and verify the stopper holds water—there should be no leaking around the edges.
9. Dissolve Mineral Deposits. If water still leaks around the stopper after reassembly, the problem is likely mineral deposits or debris on the drain seat itself. Pour a cup of white vinegar down the drain and let it sit for 15 minutes to dissolve mineral buildup. Plunge hard several times to dislodge debris. Alternatively, carefully use a small piece of very fine steel wool (0000 grade) on the drain seat, moving in a circular motion. Be gentle—you're cleaning, not scraping. Rinse thoroughly with water.
10. Swap in a New Stopper. If cleaning and adjustment haven't solved the problem, the stopper itself may be warped, cracked, or the rubber seal may be permanently hardened. Remove the stopper again and take it to your hardware store to match the size and style. Most sinks use a 1.25-inch or 1.5-inch stopper. Purchase an exact replacement and install it by reversing the removal process—simply drop it into the drain and ensure it sits level. Test the mechanism again.
11. Replace the Entire Assembly. If the pivot rod is severely corroded, pitted, or bent, or if the drain assembly housing is cracked, you'll need to replace the entire pop-up mechanism. First, unscrew the drain assembly from underneath the sink (it's held by a locking nut). You may need a basin wrench if the nut is tight. Lift out the old assembly and take it to the hardware store to match the diameter and style. Install the new assembly by screwing it in place, ensuring the overflow hole (if present) aligns with your sink's overflow opening. Reattach the pivot rod and cotter pin. This is more involved but still a straightforward plumbing fix.
12. Seal Remaining Leaks. Once you've completed repairs or replacement, check under the sink again. If water leaks from the drain nut (where the assembly connects to the drain), tighten the nut with a basin wrench. If it still leaks, turn off the water supply, remove the assembly again, and apply plumber's putty or a new rubber washer under the drain flange before reinstalling. Turn the water back on and test.