Most sinks include a pop-up stoppers that control the water retention in the bowl of the sink. Pulling the stopper rod on top of the faucet closes the stopper to retain the water in the sink. Pushing the stopper rod pushes the stopper up as it pivots underneath the sink and allow the water to drain out of the sink and down the drain. Thorough cleaning of a pop up stopper ensures correct functioning though adjustments are sometimes necessary.
Push the stopper rod on top of the sink to lift the pop-up stopper. Grasp the stopper inside the sink and pull it straight up and out or turn it one-quarter turn counterclockwise and then lift it out. Some stoppers need turning to unlock them from the pivot rod.
Clean any hair or debris off the bottom of the stopper and dispose of it. Shine a flashlight into the drain in the sink to find any additional items that need removing like small pieces of paper. Bend a wire coat hanger and insert it to grasp any blockage in the sink drain.
Examine the stopper to ensure that the rubber O-ring seal on the bottom does not have cracks and is intact. If the O-ring has damage, the water will not remain in the sink when the stopper is activated. Replace the stopper if it has a damaged O-ring.
Loosen the plastic retaining nut underneath the sink on the pivot rod by turning it counterclockwise with an adjustable wrench. The retaining nut is on the end of the pivot rod, which is a horizontal rod that lifts the stopper.
Loosen the setscrew on the clevis with a small flat screwdriver by turning it counterclockwise. The clevis is the vertical rod with holes in it that connects to the pivot rod.
Place the stopper back inside the bottom of the sink by either dropping it in or turning it one-quarter turn clockwise.
Adjust the clevis up or down to adjust the stopper. Moving the clevis up will open the stopper higher in the bottom of the sink. Moving the clevis down will seal the stopper in the bottom of the sink tighter to the bottom.
Tighten the setscrew on the clevis by turning it clockwise. Tighten the plastic retaining nut with adjustable pliers by turning it clockwise.
Test the stopper for correct operation and make any other clevis adjustments up or down as need be.
Pop-up stoppers that open the drain higher will let the water in the sink rush out at a quicker rate than stoppers that open partway. Higher opening stoppers also let more hair and items that drop into the sink enter the drain to clog it. Home improvement centres and plumbing supply stores carry replacement stoppers.
Do not over tighten the plastic retaining nut or it will break. When replacing a pop-up stopper remove the old ineffective stopper and take it with you to the store to purchase the same type. This ensures easy replacement with the correct fit.