My hydraulic oil gets hot after a couple hours use in the hoe but doesn't get hot nearly as quick while using the loader. It seems like while driving it cools down better. Do oil coolers get clogged or restricted internally? Could it be as simple as cleaning the dust out of the cooler veins? Does a clogged filter cause these problems? Is there an order or checklist of what to replace or inspect? Any help would be greatly appreciated
Yes, dust builds up and blocks the airflow. Yes, clean out the dust, hopefully there's no oil to cement the dust in place. Highly unlikely that a clogged filter would cause this problem. The #1 thing to check is the oil cooler, take it off if you have to, use a tiny pick if you have to, soak it with dawn dish soap and LIGHTLY pressure wash if you have oily gunk. Shine a light through it and look that every fin is clean. Also, check that the fan is in good shape, foam is in place, belt is tight, not glazed etc. When you're positive that it's clean, if it still overheats then come back for more option.
I agree with delmer, especially when these coolers are mounted in front of the rad, they tend to build up junk in between the rad and cooler.
How hot is hot? Hydraulic systems will run 100 deg over ambient temp or more which is darn hot on a 80-90 deg day 180 oil would feel real hot. Would be interesting to check it with a thermometer when hot to be sure where you are at, does it have an oil temp gage in the hydraulics? My experience is with Case and they did not and I do not remember JD units I have been around having one either.