According to the information given to me by a senior Kaw service tech who authorised the replacement of my faulty unit 2 and a bit years ago (free of charge for investigation of the failure), the solenoids and therefore valves are cycled each time the bike is started and ridden those first few metres. If the system is 'fault free' the ABS warning light is extinguished. As we know, the ABS light goes off even with this fault, though the FSM details (in one of the other thread) that it is designed to detect this fault and warn the rider.
Jamie, I'm assuming (perhaps wrongly) that the solenoids are under the caps near your thumb. Is that so?
The cap by my thumb, is where the piston, driven my the pump motor are installed by the manufacturer. It's very difficult to install the pump motor, without taking out those pistons, because they ride on a cam, driven by the motor. It turned out to be unnecessary to take off the motor. Wish I'd known that ahead of time. You can see the pistons in the top pic.
The solenoid that sticks, is accessible by removing the control module from the back of the ABS unit. I simply worked the stuck shaft loose with a soft mallet. Once it started moving, I was able to use my fingers to work it in and out while pouring fresh fluid through it. A little dirt came out but I've seen cars that were much worse, and still functioning. I'd say Nissin screwed the pooch designing this unit.
Here is the pump motor in the bottom pic. If anyone ever attempts this fix on their own, I recommend NOT removing this, since it doesn't gain access to the problem area, anyways. It's damn tough to reinstall this this between the two opposed pistons.