Overheating in NW Mountains

If you can't accelerate uphill, you're in the wrong gear. Spray radiator fins with 409 and backwash it with garden hose to remove bugs. Do not pressure wash

 

Perhaps if it drives water pump. Keep on Truckin, Americans need your help. Find a decent local shop with some good ol' boys to address any questions or concerns and learn to eventually self address some recurring issues.

 

I suggest, before you hit the hill manually turn on the engine fan. If your truck is not equipped with one I suggest you install one. Also suggest you pressure wash the radiator out. Be very careful, as not to damage the fins. Use a good degreaser first.

 

Pressure wash rads out all the time. Never had an issue. Hit it straight on so that you don't bend the fins over and give'r the ketchup until there's nothing but clean water flowing out.

 

A gauge with a few fittings and some 1/4 inch tubing is maybe $30. A little of your time and a few wrenches.
Dealer here is $140 per hour.

 

Your truck should already have wiring for a manual fan in the harness. Should be able to add a switch, relay and maybe a solenoid. Look for the right good ol boy shop or sometimes $140 an hour is cheap if they know what to do.

 

I never did that on exactly your engine model and none of them are left here to look at.
It has to be attached to the engine after the oil cooler and before the front of the head - thermostat. Just an inexpensive 100 PSI gauge, some fittings and 1/4 inch plastic air brake hose.
This is a little bit of an aloosive thing to check. Even most experienced techs blow it off. Some of the old Cummins had different diameter drive pulleys and impellers. A friend having a problem with a low flow Cummins told me I bought the manual. I have read all of it but it does not say anywhere that it should have 52 PSI at rated speed. Where did you get that from? The school of hard knocks.
I would check out your belt, pulleys and things others have mentioned first.