the possible cause is the unloading auger swing-home limit switch is failing whenthe auger is swung home and the switch is not neutealized.this causes the pump to stay in stroke and overheats the oil.the temporary fix is to make sure the switch is moved to neuteral or install the timer upgrade avaliable at JD
What header is attachedIJ If a cornhead is on, have you reconnected your reel drive hoses back together at the feederhouse properly so that oil loop is free flowingIJ