Twin Alternating Brine Failure on ONE Tank Only

If your system uses one the twin alternating control valves ( common models are Fleck 9000, 9100, 8500, TwinFlo 100E, and Fleck 9500 ), and the Brine Suction cycle is failing to draw up the Brine from the Salt tank when unit is operating off one tank, but okay on the other ( i.e. when on Tank 1, works great, but when switches to tank 2, brine suction is not created ),
THEN, the problem is an internal leak of the LOWER Piston & Seals ( or cage rotor on the 8500 ).
Replacing these ( Lower Main Piston and Seals & Spacers Kit - Cage Rotor on 8500 ) should solve the problem. While a rare problem to have, I just had another customer call about this exact problem.
Thus, the new article explaining this unique repair issue.

A Single Tank ( valve on one Resin Tank ) System will also fail to draw brine ( suction of the salt water ) if the valve has internal seal problem.
This is more common on the rotary type valves ( Ecowater's valve used in Sears Kenmore, GE Smartwater, North Star, and others ), but can occur on any older ( 10 plus years ) valve, due to worn out Piston & Seal ( Fleck models ) and Valve Disc ( Autotrol Models ). It's one of the half dozen reason listed in our # 1 FAQ article about high water in the brine tank ( because it is not sucking any out ).