Jon,
From what I can tell the pump impeller did not have any broken blades and the blades would turn as the shaft was turned. It was of course dirty inside; looks like rust and antifreeze "gook" may have blocked inside the pump itself.
We removed the radiator in order to get to the water pump, so while it was out I hosed it out until the water going thru it was clear. I also turned the radiator upside down and removed some more water that had accumulated in the bottom.
We installed the new pump and ran it with pure water to see if the water would move (we removed the thermostat to do the test). We had good strong water flow in the neck of the radiator so we drained the water and re-filled with 50/50 pre mixed Prestone antifreeze.
I would say that removing the radiator and washing it out is good preventive maintenance. I plan to do it every 2 years when I change my antifreeze. Turning the radiator upside down and draining excess water thru the neck is key IMO. This should be done a few times to get all the gook out.
Sure is a good feeling to have the generator running at normal operating temp.
Tuga & Karen Gaidry
2012 Honda Pilot