2016 cuminns isx15 over pressure in overflow

[702autotech]

thanks everyone for the advise im trying everything that you suggested but it takes awhile. I didn't watch for bubbles in the reservoir I ran a hose from the pressure test cap into a bottle of water and let it warm up and then ran it at 1400rpm and nothing, and the small hose from where the thermostat is just pours coolant out when disconnected but the one that is above the coolant goes to the top of the radiator i pinched off., I also did a block test on it and never changed color, I took off the line from the compressor to the filter and it was dry.