1988 cat 426 overheating

I just replaced the water pump, new belt, new thermostat and complete coolant change in my cat backhoe today. Ran it for 2 hours and it started overheating again over 220 degrees. I did NOT put the thermostat in wrong, but what i cant figure is how I can not see water moving through the radiator with a brand new CAT waterpump. Anyone heard of any internal restriction issues with this perkins motor? All the hoses are good and machine though old barely has 7000 hours. Any help would be appreciated. I did do a pressure test on radiator and no leak down detected. I am just plain stuck.:(

1988 cat 426 overheating