Water – How to repair a drain that won’t stop leaking

I would suggest using a product called "Sealsall". You can get it at any hardware store. This stuff is easy to use, Dry the seam as best as you can, then just apply some to the leaking seam before it gets too wet again. Try not to get it on your fingers as it will take a week to get it off!! Sealsall dries clear and should be good for years. I have used it on everything from a canoe bottom, car gas tank, to hot tubs with success. Good Luck

Sounds like a bad O-Ring on the stopper.

Here is a good picture for reference.

To remove the stopper, you'll have to remove the retaining nut at the back of the drain body. Once that's removed you'll pull the pivot rod out, this will allow you to remove the stopper.

Now that you have the stopper out, visually inspect the rubber gasket around the bottom of the plug (just under the chrome part). If the gasket is worn or cracked, you'll have to either replace it, or the entire stopper.

If you take the stopper with you to the hardware store, somebody there should be able to help you find what you need.

To put it all back together, put the stopper in the drain, insert the pivot rod (so it interacts with the stopper), then tighten the retaining nut back down. You can make minor adjustments by loosening the set screw that holds the lift rod to the clevis, and adjusting how deep the lift rod goes into the clevis.

WARNING:

Don't over tighten the retaining nut, or you could find that you won't be able to move the lift rod.