How to Install Kohler Part 83991

Shut off the water supply to the toilet by turning the handle on the shutoff valve — usually near the base of the toilet — in a clockwise direction. Shut off the water supply to the home if you cannot locate a toilet water shutoff valve.

Flush the toilet to empty most of the water in the toilet tank. Remove the lid from the tank and finish removing any remaining water with a sponge.

Place a towel under the water supply line under the toilet. Loosen the nut on the line where it attaches to the underside of the toilet tank with a pair of pliers. Finish removing the hose by hand.

Loosen and remove the three nuts on the underside of the bowl flange at the back of the toilet with a socket and ratchet wrench. Lift the toilet tank straight up and remove it from the bowl. Lower the tank on a towel that has been placed on the floor.

Loosen and remove the plastic nut from the underside of the tank with adjustable pliers and discard it. Remove the gasket that was underneath the nut and discard it, as well. Reach inside the tank and pull the three retaining bolts straight out. Remove the rubber gasket from the underside of the tank and discard it. Unhook the stopper chain from the flush handle lever inside the tank. Pull the filler tube and the stopper straight out of the tank and discard them.

Position a new gasket from the kit over the mounting holes and the inlet hole on the underside of the toilet tank. Insert the threaded end of the replacement filler tube from the flush valve kit into the hole in the bottom of the tank. Place a new gasket from the kit onto the threads protruding from the underside of the tank. Twist a new plastic nut from the kit onto the threads and tighten it with pliers.

Hook the holes in the arms of the replacement stopper from the kit onto the two tabs at the base of the filler tube now installed in the tank. Hook the chain from the stopper onto the hole in the end of the flush handle lever.

Position the tank over the bowl, ensuring that the holes in the tank align with the holes in the bowl. Insert the three retaining bolts through the holes in the bottom of the tank. Thread the retaining nuts onto the threads of the bolts protruding from the underside of the rear bowl flange. Ensure the bowl is sitting level and straight. Tighten the bolts with a socket and ratchet wrench.

Replace the toilet tank lid. Thread the water supply hose to the underside of the toilet tank and tighten it with pliers. Turn on the water supply to the toilet.