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.