How to test the water pump to see if it is working?

You can remove the pump to inspect the water pump impeller. Here is how to remove the water pump so you can check out the internal workings of the pump. I would say to remove the radiator cap to check for the flow but if the impeller is partially missing it will still show flow but not enough. Check out the images (below). Please upload pictures or videos in your response to any problems so we can see what to help you with.