Kohler Tub Drain Stopper Not Working. Hold a large enough jam or other jar lid over the drain upside down. Insert a drain snake into the drain line and turn and push to loosen any debris that’s blocking the drain.

If the drain stopper is not moving or closing, check the adjustable link. The lever seems to be stuck in the down position. Insert a drain snake into the drain line and turn and push to loosen any debris that’s blocking the drain.