Water Softeners and Air Filtration Systems - Fleck 5600 not filling brine tank

My Fleck 5600 Economizer seems to work fine in all positions except for Brine Tank Fill.

I've had the unit completely apart. Nothing is rusted, broken or missing. All valves operate smoothly, all rings and parts are properly lubricated. Theres no mold or deposits anywhere. None of the screens are clogged. The mechanism of the Brine Tank Fill Adjustment comes around the dial, pushes the valve downward, allowing liquid to flow to the brine tank works fine. I've actually sat and watched it go through it's cycle, everything looks like its working properly, yet no water flows from the Fleck unit to the Brine Tank. I simply don't understand why water isn't flowing into the brine tank.

Theres no clogs in the line (I know this because A. I checked and B. The line will draw water from the brine tank into the Fleck unit during Brining cycle). I don't have a safety float in the brine tank, just a regular pickup tube with air check, which seems to be working properly, the ball inside floats freely and isn't stuck. I've even gone so far as to try sucking on the tube during Brine Tank Fill, to see if it is a question of pressure, without any success.

Anybody out there have any idea what else could be happening?

The spring valve behind the capacity meter may need to be replaced.This is pushed down when trying to fill the brine tank.If it is damaged ,you get zero to low brine flow. Also, The brass fitting on the side of the valve connected to the brine line should be removed and inspected. Even the smallest piece of debris can be hanging out in that plastic piece waiting to be pushed into the flow restrictor. One of these two will fix the problem. --good luck