How to Remove & Replace a Moen Cup Seal and Diverter

Moen's cup-seal diverter, sometimes referred to as a gate diverter, serves the dual purpose of directing water to the bathtub and, when the diverter is actuated, routing the water to the showerhead. Within the assembly is a cup seal designed to prevent water from exiting the tub spout when the diverter is operated. It is for this reason that a leak from the tub spout when the shower is in use is attributed to a worn seal. The seal and diverter are within a single assembly and cannot be repaired. Replacing the assembly, however, is a straightforward job.

Anticipate spending approximately 15 minutes replacing the diverter assembly. (Image: Jupiterimages/Photos.com/Getty Images)

Things You'll Need

  • Channel-type pliers

  • Wire brush

  • Plumber’s tape

  • Masking tape

Step 1

Grasp the base of the diverter assembly with channel pliers.

Step 2

Rotate the diverter assembly in a counterclockwise direction until it detaches from the water supply pipe.

Step 3

Remove any old plumber's tape from the threaded tip of the water supply pipe by scrubbing the tip with a wire brush.

Step 4

Wrap the threaded tip of the water supply pipe with new plumber's tape.

Step 5

Position the new diverter assembly onto the tip of the water supply pipe. Rotate the assembly in a counterclockwise direction by hand to ensure that the threads of the pipe align with the threads inside the assembly.

Step 6

Wrap the jaws of the pliers with masking tape to avoid scratching the finish of the new diverter assembly.

Step 7

Turn the diverter in a clockwise direction with the pliers until the back of the diverter rests flush against the shower wall.