Hi George,
If your hydraulic fan is running correctly, it should be quite loudly moving air. If it is not, then you know your problem is within the solenoid actuator assembly. I would hate to see you lose your nice rebuild over this silly piece.
However comma, your bleeding results are not good and I can tell you my story about that exact thing. My engine baked one day due to a bad water pump. The plastic aftermarket impeller equipped water pump had failed, and while troubleshooting, I went from just a bad water pump to a cracked head, cylinder, or blown head gasket in 2 hours. This was after 276K miles. After finding a lower miles engine the next day for $400, I extracted the old engine and moved all the sensors, etc to the new one. I had not yet realized that my lifetime warranty Autozone water pump was the culprit for this entire incident, and like a dummy, I moved that water pump to the new engine since it was lifetime warranty. After running it and seeing the degas bottle overflowing, I wasn't sure what the problem was, but went and bought a water pump and a DCCV. I changed the DCCV first, no change, then I pulled the water pump and low and behold, it had loose parts inside, and sure enough it was the impeller that precipitated the whole problem. Since Joe had suggested that the pump impeller could have something to do with your flow issues, you may want to bite the bullet and pull that water pump. My air purge procedure had the exact same symptom as yours with no impeller, namely, the flow out of the heater bleed was negligible. In fact, it would only flow with 2K rpm or so, which at the time, I was not able to know why, before learning about the impeller falling off. You obviously still have an impeller, or the car would not be driveable, but the vanes may be angled in the wrong direction as if it was built to be used on a FWD 3.0 engine, if that is even a possibility. But check the fan speed first, it should be very loud when it gets over 210.