I'm having the same issue right now in my 03. I'm down here in AZ so driving in the summer with no AC is horrible. I had the water pump replaces a few years ago and this past winter I had the thermostat replaced when I had the radiator flushed. I thought this would helped out but when the temps his over 110 it started over heating and shutting down again. My thinking on my next move is to replace the radiator.

 

Dexacool gets nasty when its mixed with not Dexacool. I think its pretty good stuff when its never mixed and maintained properly.

These trucks can be a little tough to fully bleed. I park on an incline nose up and use a bleeding funnel in the radiator fill at high idle and make sure the heater hoses get hot.


George