Overheating

[donaldray]

Broke down in Three Forks, Montana. Took thermostat out and truck could not get up hill without overheating 3 times. Made it too flying J and notice leak under water pump and currently got it off too replace. Question is this: If water pump is not problem . Can I Flush system too clean out EGR cooler and can I leave thermostat out untill I get too Dallas, Tx.? And can I run with just water with no antifreeze for that far. Don't want too throw money at it until I know for sure if it was the pump.