How to Replace a Bathtub Overflow Gasket

Step 1: Confirm the overflow gasket is the likely leak point

1. Dry the tub wall around the overflow cover, the tub floor, and any ceiling or wall area below the tub if you can access it.
2. Run water into the tub without using the shower and watch for leaks. Let the water rise until it reaches the overflow opening.
3. If the leak starts only when water enters the overflow, or when shower spray hits the overflow area, the gasket is a strong suspect.
4. If the tub leaks even when the water level stays well below the overflow, the problem is likely somewhere else such as the drain, shoe, waste-and-overflow connections, or supply plumbing.

If it works: You have a leak pattern that points to the overflow opening and gasket.

If it doesn’t: If the leak happens with low water levels or from another area, stop chasing the overflow gasket and inspect the drain and nearby plumbing instead.

Step 2: Remove the overflow cover and expose the old gasket

1. Put a rag in the tub so dropped screws do not disappear down the drain.
2. Remove the screws from the overflow cover plate and pull the plate straight toward you.
3. If the plate is attached to a trip lever or linkage, move slowly and support the assembly as it comes out so you do not bend it.
4. Shine a flashlight into the opening and locate the rubber gasket sitting between the tub and the overflow elbow behind the wall of the tub.

Step 3: Pull out the old gasket and clean the sealing surfaces

1. Use your fingers or needle-nose pliers to pull the old gasket out through the overflow opening.
2. Note how the old gasket was oriented before removing it fully. Many are thicker on one side to match the angle between the tub and overflow elbow.
3. Wipe the tub opening and the face of the overflow elbow clean with a rag.
4. Use a plastic putty knife to remove stuck residue or old buildup, then wipe the area dry.

Step 4: Install the new bathtub overflow gasket

1. Compare the new gasket to the old one for size and profile before installing it.
2. Position the gasket in the same orientation as the original, with the thicker side where needed to match the tub's angle.
3. Hold the overflow elbow in place behind the tub opening and seat the new gasket evenly between the elbow and the tub.
4. Make sure the gasket is not folded, pinched, or sticking out unevenly into the opening.

Step 5: Reassemble the overflow cover without distorting the seal

1. Guide any trip lever or linkage back into the overflow tube carefully if your tub uses one.
2. Set the cover plate in place and start the screws by hand so they do not cross-thread.
3. Tighten the screws evenly until the plate is snug. Do not overtighten, because that can shift the gasket or damage older parts.
4. Wipe the area dry so any fresh leak will be easy to spot during testing.

If it doesn’t: If the plate will not sit flat, remove it and check whether the gasket or overflow elbow shifted during assembly.

Step 6: Test the repair under real use conditions

1. Run water into the tub until it enters the overflow for at least a minute while watching the area below or behind the tub if accessible.
2. If the original leak happened during showers, spray water directly at the overflow cover and surrounding tub wall as a second test.
3. Check for drips, dampness, or water tracks around the overflow opening, behind the access area, or on the ceiling below.
4. Use the tub normally over the next day or two and recheck the same areas once more.

If it works: No water appears during overflow testing or normal use, and the repair is holding.

If it doesn’t: If water still shows up only during overflow use, reopen the assembly and check gasket orientation, seating, and part fit. If the leak pattern changed, inspect the drain and waste-and-overflow connections next.