truck running a little warm

well back to work since the weather is getting better but the last 2 days the truck seem to run a little warmer then before ..any ideas on why or what to check on this??? its a cummins m11 280 with a 9ll..i replaced the waer pump a year or 2 back but didnt replace the stat and thinking to try that and a new cap...also replace the surge tank a few yrs ago had a hole init....what sta would you guys recc. for this i would like to get it before i take the old 1 out..oh its a dump truck....the temp runs about in the midd. most of the time but now its about half way to the red and when empty its still over the half mark..not useing water..thanks for the help mike

 

now that i have not done i do spray water init with a hose from time to time but not press. and the radi. is about 3yrs old replaced it cause the factry 1 fell apart on me at work 1 day ..but thanks ill do that tomm. while im off trying to fig. out whats going on with it..mike

 

whats a cac ????

 

thanks guys after i typed what is a cac and posted i said maybe the charge air lol i'll look in to that as well mike