Thank you all, I will have the water pump replaced. I did replace the expansion tank cap after the hose blew off (when I replaced the thermostat).

I will also have the coolant flush done at the same time - I wonder how many flushes to remove all the shavings? Is it necessary to have a perfectly clean cooling system - void of even tiny metal shavings? I wonder because I doubt all of the shavings can be removed with a flush(es) short of tearing apart the motor and replacing the radiator tank?

I wonder what caused the water pump impeller to grind into flakes? Maybe I did not have the correct coolant? I was using the Zerex G-05 and water and finally added a pint of water wetter. Maybe the mixture was to much water?

Jim