Water Softener constantly draining water

I'm hoping somebody can help me save a lot of money.

My softener is constantly draining water to the drain tube. Even when the brine tank is empty.

I cleaned/checked the float, and the tube running from the resin tank to the brine tank. It was badly clogged, and I thought that would fix the problem. I plugged it back in, forced a manual regeneration and the brine tank filled, then drained, and even after it was empty it just keeps gurgling down there like it still wants to suck in more water for hours. Meanwhile the drain tube (that leads to my house drain) is constantly removing water from the control valve. Even if I unplug the timer.

I'm guessing that the problem is with the control/valve or the timer.

The timer is an old school mechanical Eerie and keeps good time (if nothing else).

Does this symptom (constantly running water through the main drain tube) sound like a timer that is stuck in a cycle, or an improperly functioning valve.

Or is it possible the resin tank has gone south.

I just got an over-the-phone quote for $1400 for a whole new unit with Clack Valve, but would rather just fix the old one.

Any ideas or help with diagnosing is greatly appreciated.