Replace the old, worn Valve Discs on your Autotrol water softener with this genuine Autotrol valve disc kit, known as a flapper set. This set contains two discs replacing the two you pull out of the valve body.
To take out old discs: remove the screws holding the top plate down, then remove the cam and timer housing. The flat springs will pop out of the top of the valve discs. Use a pair of needle-nose pliers to remove the springs and when finished, put them back.