If the pop-up drain in your bathroom sink has stopped working, a simple fix may get you popping again in no time.

Step 1: The pop-up mechanism on a bathroom sink is composed of three parts, the stopper, the ball rod and the pull rod assembly. The pull rod is attached to the knob you lift and lower to move the stopper up and down. The ball rod is under the sink. It goes into the drain line and through the bottom of the sink stopper. Reach behind the drain line, under the sink, and locate the retaining nut that holds the ball rod in place. Unscrew the retaining nut from the drain line.

Step 2: The ball rod is secured to the flat metal portion of the pull rod assembly with either a spring clip or two movable washers. Pinch the spring clip or remove the outer washer to free the ball rod from the pull rod assembly.

Step 3: Once the ball rod is free, remove the retaining nut and any washer between it and the ball. Place the nut and washer in a safe place as you will be reusing them later.

Step 4: Use the old ball rod to determine the size of the new ball rod. Universal replacement ball rod kits usually contain multiple-sized balls. Select the one that is the most similar to your old one. Assemble the new ball rod by placing the retaining nut and old washer above the ball and securing half of the spring clip or one movable washer on the other end of the new rod.

Step 5: Slide the rod end of the new ball rod through the flat portion of the pull rod assembly.

Step 6: Slide the ball portion of the rod into the drain line and hand-tighten the retaining nut into place.

Step 7: Lift the pull rod assembly up from the top of the sink to make sure the ball rod assembly is positioned properly.

Step 8: Make any necessary adjustments. Secure the other side of the spring clip, or the second movable washer, onto the far end of the ball rod to finish the installation process. Check to make sure the retaining nut is securely tightened to the drain line.

Check the functioning of the sink stopper and pop up and down at will.