After installing new flapper valve disc set in my Autotrol Valve, I checked the function before powering up timer. The valves all seemed to work. I then turned the water flow back on and have a flow from the drain line. I removed the cam and checked the flapper by hand each seems to close and open properly. What is your suggestion?
One of the Rear Valve Discs is not sealing ( last 2 are the Backwash, and the 3rd from last is Purge - Forward Rinse ). This could be debris that flowed up into the head, or it could be cracked plastic inside the valve body where the valve disc "rest" and "seal" when closed ( standing straight up ). ** Recommend removing top plate ( all those little screws on top ) and valve discs ( they pull straight up and out ) and make a close inspection with a flash light for any signs of debris, or a cracked "port" inside the valve body. ** Repair may be as simple as clearing the debris ( which can be media from the tank, or some other odd thing ), or if valve body is cracked, then the valve body will need to be replaced ( if still available ), or complete valve head can be replaced by compatible current version of a similar Autotrol Valve.
EMAIL US for further assistance if this is the case ( cracked internal valve port ).
The flapper valve discs can be replaced by removing the 11 or 12 screws holding the top plate on ( you need to remove the cam and the timer housing first ). The flat springs pop out of the top of the valve discs. A pair of needle noses pliers helps with removing the springs ( and popping them back in place ), and also with pulling the valves out of the valve body. It is a fairly simple procedure.
PLEASE check carefully that the area where the valve disc "seat" is 100% clean, and be sure to Install the Discs into the Valve Body, and THEN lower the Top Plate on top. The Valve Discs must all be INSTALLED and SEATED first, for best possible results ( less chance of problems or leaks ).
The only other "tricky" part is to be careful putting the screws back in.