2013 Pete ISX15 Overheating

I have a 2013 peterbilt 587 isx 15, 705,xxx
It overheats when I pull big grades or run high rpm's for long periods. Coolant resting 180 overheat 220/ Oil temp resting 220 overheating gets 255 then I get red shutdown light then 30sec later it shuts off. If I cycle the key on/off I can keep rolling like everything's fine.
Things I've replaced are coolant(no leaks & new cap) cleaned radiator, coolant level sensor, oil temp sensor, coolant thermostat, oil cooler/oil thermostat, sensor that tells the clutch fan to kick on. There's no oil in my coolant or coolant in oil, no white or black smoke from exhaust & no bubbles in coolant reservoir.

 

I'm a fan of his & still can't find a solution. Shops can't figure it out so idk

 

Yes the coolant system is holding pressure now.

 

Air is being pulled through

Yeah I've unplugged the sensor to make the fan run full time, it still overheats just takes a bit longer to shut down.

 

The fan kicks on full blast when coolant hits 211 shuts off at 205. Air is being pulled through, my coolant temp drops back to 180 after I pull hills so it is cooling.