Tractor Repair: Case IH 7140, coolant temp, chisel plow

Question
I have two questions about my '89 Case IH Magnum 7140 tractor. What is the optimum operating RPM and speed when pulling a 15 foot disc or chisel plow? I've been running it at 2000 RPM at 5.2-6.5 mph, but it runs pretty hot at that speed. The gauges are just below orange and sometimes go to orange on the exhaust temp and coolant temp. That's very close to the red overheating temp. Why is it running so hot? Is it the RPM and speed?

Answer
It is not your speed you are running hot. Make sure you do not have air in the cooling system . When the engine is cold open pecock valve on top of the aftercooler on the engine. Fill it with coolant till it runs out of the valve then top it off. Check your fan clutch when the engine is hot the fan should stop with the engine it should not freewheel. If it does then the change out the clutch. Do not run this tractor until this problem is solved unless you are comfortable with rebuilding the engine or buying a short block.