Todd...your machine should have a round rubber sleeve seal up in the scrubber cap...it's about 1.25 inches in diameter, or so. Most of it fits up in the recesses of the cap, and is meant to mate up with the groove in the top of the agitator. This seal, when working correctly, helps prevent air loss under the agitator, which is critical to prevent water from finding its way up the centerpost and into the bearings and down into the gearcase and basket drive.
These seals can become compressed over time with tight agitator caps, but I have removed the seals and flipped them a few times so that the previously concealed parts are now able to be used.
Brun...is your seal dried out or missing or are you just wanting a new one? I did find a few new ones online.
Gordon