Our backhoe with less that 3000 hrs. runs hot after about 45 minutes of regular use. It gets progressively warmer and will eventually make it to "the red." If you check the upper hose temp then it is about 190 degrees and the lower is about 180 degrees. You can't look in the top of the radiator to look at coolant movement. Can someone give advice as to how to troubleshoot this. We think we have the exterior of the radiator clean. Also if you take the side shields off and let it idle it will eventually cool down.
That sounds like not enough air movement to me. 190 doesn't seem hot, but within the margin of error, what's the metal temp, each end of the top and bottom hoses? DOUBLE check the outside of the radiator, can you see through the whole thing if you have a light on one side and look at the other? check the belt tension. What is the history of coolant maintenance? apparently radiators can gunk up on the inside enough to slow heat transfer without slowing coolant movement. That might apply to much larger radiators than this though.