Things You'll Need
2-by-4-inch block of wood, 1-foot long
Replacing a leaky sink drain requires removing the existing sink drain flange. The drain flange is the part of the drain you see from the top of the sink. When attempting to remove the old one, you often find that the entire flange turns with the nut. Most often this is due to rust or sediment that develops on the threads between the flange and retaining nut. Plumbers have special tools to counter this issue, however homeowners are still able to remove a stuck kitchen sink drain flange with regular hand tools and a helper.
Spray penetrating lubricant onto the threads between the securing nut and the drain flange. Spray around the bottom where they meet, and spray between the top of the nut and the sink. Allow the lubricant to work for ten minutes.
Grab a pair of slip-join pliers, and stick the handles inside the drain cross piece. The handle should go into two opposite holes. Insert a screwdriver between the handles, and ask your helper to hold the pliers in place using the screwdriver as a handle.
Turn the securing nut under the sink counterclockwise with the pipe wrench. Sometimes to get the nut turning, it is necessary to turn the nut clockwise just enough to break the rust or sediment seal. Once the rust or sediment breaks just a little, the nut will turn counterclockwise. The handles of the pliers will help keep the drain flange from turning with the nut.
Place a block of wood flat against the bottom of the drain flange. Hit the block of wood a couple of times with the hammer. This will raise the sink drain flange up from the sink just enough to work a putty knife under it to cut through the putty adhesive.
Go to the top of the sink and insert the putty knife between the drain flange and the sink. Cut through the plumbers putty with the putty knife while lifting the drain flange with your fingers. Continue working through the putty until the drain flange is out of the sink.