How to Replace a Sink Pop-Up Stopper

Drainage is the unsung hero of bathroom utility, and nothing ruins a morning routine faster than a stopper that stays stuck or refuses to seal. Whether your finish is tarnished or the internal mechanism has simply corroded into a permanent state of failure, replacing the pop-up assembly is a definitive fix that restores full function to your basin. Done well, a new stopper sits perfectly flush when closed and clears the drain path entirely when open, preventing the slow-draining water that leads to grime buildup. You do not need a plumber to handle this, just a bit of patience under the cabinet and the right wrench to tighten the new seals into place without cracking your porcelain.

Clear Your Work Zone. Empty your vanity cabinet and place a bucket or a large towel directly beneath the drain pipe. This catches any residual water that will spill once you loosen the plumbing connections.
Disconnect the Lift Rod. Reach behind the drain pipe to find the clevis screw holding the lift rod strap to the pivot rod. Unscrew the thumbscrew to disconnect them so the stopper mechanism can move freely.
Extract the Pivot Rod. Use your fingers or a pair of slip-joint pliers to unscrew the pivot nut connecting the horizontal rod to the drain pipe. Pull the rod out carefully, ensuring the stopper ball comes with it.
Remove the Old Flange. From inside the sink basin, unscrew the drain flange. If it is stuck, you may need to use pliers on the internal threads or hold the drain pipe from below while turning the flange top counter-clockwise.
Seal the New Flange. Apply a thin, consistent ring of plumber's putty around the underside of the new flange rim. This creates the watertight seal that prevents water from leaking into your vanity cabinet.
Install the New Assembly. Insert the new drain flange into the basin and tighten the lock nut and gasket from underneath the sink. Reinsert the pivot rod through the new stopper and tighten the pivot nut until it is snug but not over-tightened.