I have a 2015 f150 4wd with 5.0

I have replaced entire cooling system ( all hoses fittings, thermostat, cap, water pump & coolant temp sensor.. truck is still trying to over heat.. or atleast my gauges tell me it's overheated

 

Is there a check engine light?
If so what code is set?
Did you use a Ford Thermostat replacement, not an other after-market part? It makes a big difference.
Are you sure all the air is purged from the system?

 

If all other things check out & you used a non oem thermostat replace it again with genuine ford stat....night & day difference!!
Persanally I know duralast (Advance auto) stats do not work same as CTC & napa here in canada !!

 

How long ago did you make the changes?
The thermostat could be suspect if it's not FoMoCo.
I would venture a guess as to what is happening and bet its air in the system. Are you running max heat and cycling the system through the heater core?
Have extra distilled water on hand, if you start to see the coolant levels drop it could be the system purging air... you'll want to top it off.

 

You might wonder why an aftermarket thermostat would cause the engine to overheat. The short answer to that is: The thermostat isn't fully closing off the engine bypass loop in the thermostat housing like it should whereby, much of the heated water from the engine is circulating back through the engine rather than being forced through the radiator, throwing off the balance to maintain an at temp level, causing higher temperatures to build in the engine loop. What is the bypass loop bypassing? The radiator loop of course. When the engine bypass loop is fully closed off by the thermostat element all the hot water from the engine is then being forced through the radiator loop and back to the engine.