The sink drain stopper in the bottom of your sink raises and lowers by means of a push rod to trap water or allow it out of the sink drain. This lets you to use your sink basin as a wash tub for soaking delicate items of laundry or giving your little one a bath. The stopper has a rubber seal around the edges that keeps the plug watertight. Over time, this washer can deteriorate. The stopper can also attract debris such as hair and mildew underneath, which will prevent it from closing properly.
Push down on the stopper lever to lift it up and out of the sink flange. Insert a small piece of wood or plastic underneath the stopper to prop it open.
Loosen the coupling on the back of the tail piece with a pair of pliers. Pull the ball joint and stopper rod out of the tail piece.
Pull the stopper up and out of the drain. Clean off any hair or other debris with the nylon brush. Examine the rubber washer around the rim of the stopper. If this is torn or otherwise damaged, the entire stopper needs to be replaced, as it will no longer hold water.
Insert the stopper into the flange opening.
Slide the ball joint and lift lever back into the opening on the tail piece. Tighten the coupling.
Run water in the sink. Test the sink drain stopper by lifting and pushing the lift rod to open and close the drain. Tighten or loosen the coupling on the tail piece to adjust the stopper.