I've changed degas bottle cap water pump degas bottle hose. Still runs hot pulling load. If I cruise with load it's good. But when excel or up hill it starts for hot once I get off gass m let it coast it cools down quickly. What's next?

 

Do you have an aftermarket water temp gauge? Or are you just relying on the factory gauge in the dash? The factory gauge is not very accurite. You might want to check the temp sensor. I have a scan gauge II to monitor my temps, much more accurite then the dash gauges. My truck normaly runs 198 deg. the most it has gotten up to when pulling my 28' camper was 218 deg.

Also when was the last time you had a radiator flush? Also check your radiator to make sure it is not full of bugs and road grime, and check to see if you have a lot of bent fins. My radiator has a lot of tiny rocks and bent fins from bugs and rock hitting it.

Is your fan kicking on? Maybe the fan clutch is bad.

Hope these give you some ideas.

 

What motor do you have and how many miles are on the truck? you might have a water pump going out or a sticking thermostat. Also when was the cooling system last serviced, flush etc.. and what year?

 

He's got a 6.0...

My guess is that you're oil cooler is probably clogged or your thermostat isn't cooperating.

If someone near you has and AE monitor the Engine Oil Temperature and Engine Coolant Temperature. If the delta between the two is more than 10-11 degrees, the oil cooler is clogged and needs to be replaced along with the EGR cooler.

Are you also running Ford Premium Gold?

If it's the green "mixes with any coolant" stuff, it's a death sentence for any 6.0.

 

It's a 6.0. No egr. I chg thermostat. Yes I use premium gold. I have 364k with a coolant filter. Chg oil cooler at 176k