Top Water Pump Questions

After mounting the pump on the vehicle and after running, the shaft broke. The shaft was blue. Does this mean the pump burned up?
The pump did not burn up, however the shaft broke due to a stress fracture caused by:
- Excessive high temperatures
- Improperly torqued mounting bolts
- Bent or distorted pulley(s)
- Fan bent, cracked, not mounted squarely
- Defective fan clutch Improperly tightened belt(s)
I just replaced the water pump and my engine is over-heating. Is the water pump defective ?

The engine overheating could be due to components other than the water pump. The following should be checked and replaced, if necessary, before the pump is. Flush the system. Check hoses, clamps and seals. Check radiator cap and thermostat. Check for proper and sufficient coolant. Check for cracks, warpage and other damage.