Leak from overflow gasket on tub drain

Hi Everyone,

Firstly, thank you for putting together such an informative community to help with plumbing issues.

When we recently gutted/remodeled our bathroom, we installed a new Kohler villager cast iron tub. I went with a Watt drain assembly. Both products are from Home Depot.

After the plumber installed the tub and assembled the drain, we tested it and found that water splashed up to the triplever plate seeps out behind the tub into the basement.

After discovering this, I took out the triplever plate to make sure it was sealing properly and didn't find anything out of the ordinary. I tightened the screw on the triplever plate with more torque, but it still leaks.

I'm a bit stumped now. I could try some silicone on the gasket/pipe, but it really should seal by itself. Perhaps it's the angle of the pipes or a product defect?

Does anyone have any ideas? The irony is that we replaced the tub because the old one was rusting from the triplever assembly. So now we are sort of back to square one.

Thanks in advance for your help.
Leaking in NJ

Overflow gaskets are usually wedge-shaped...thicker on one side, tapering to thinner. This is because the back of the tub is often slanted. Check that the orientation of the gasket it such that there is approximately even squeeze at top and bottom as you pull in the screws.

At this point, I would REPLACE the gasket as part of your inspection process. Inspect the overflow to ensure it is plumb, and in the horizontal plane is parallel to the back side of the tub.

Silicone sealer doesn't hurt, but may not solve a serious installation error or wrong gasket.

If the drain looks like the one below, you may need to pull the "shoe" out with a wire coat hanger.

I snake from the upper overflow, but the linkage and the stopper need to be pulled out first.