The upper radiator hose blew. I replaced and refilled coolant, still ran hot. Then I replaced the thermostat. It is still running hot. Could it be the water pump, or am I overlooking something easier to fix?

 

What do you consider "running hot"?

 

It -could- be the water pump if you're overheating. I once had a pump break the impeller off while the bearing and seal were fine. It overheated quickly though.

I would guess that you probably haven't burped all the air out of the system or you're overdue for a flush.