A pop-up sink drain utilises that little device called a pop-up stopper to block water in the sink. The stopper can be closed by pulling up a lever at the back of the sink. This lever attaches to a rod underneath the sink that controls the rise and fall of the stopper. Pop-up sink drain repair involves removing the stopper so that you can clean it or replace it if necessary.
Place the bucket underneath the curved portion of the drain line. Loosen the couplings on either end of the P-trap. Empty the water inside into the bucket.
Follow the horizontal pull lever from the underside of the sink to where it meets the vertical lift rod for the pop-up drain. Where the two connect there should be a wing nut holding them together. Unscrew the wing nut and pull it off the rod.
Unscrew the coupling on the tail piece that holds the lift lever for the pop-up drain in place. Pull out the lift lever and coupling from the tail piece.
Insert the wooden end of the toilet plunger up into the tailpiece. This will pop the pop-up stopper into the sink above. Use a brush to remove any gunk or hair from the stopper. If the stopper is cracked or broken, replace it with a new one.
Insert the new or repaired stopper into the drain. Keep it wedged open with a small block of wood.
Apply a coating of silicone grease to the ball valve on the end of the lift rod. Insert the rod into the opening on the tail piece and thread it into the eyelet on the bottom of the pop-up stopper. You may need to rotate the stopper with your other hand as you do this to align the two. Once the lever is secure, slip the coupling over the end and tighten the ball valve in place on the tail piece.
Connect the lift lever to the push rod with the wing nut.
Apply pipe thread compound to the threads on the tail piece and the sewer inlet mounted on the wall. Slip the P-trap into place between these two pieces. Tighten the couplings.