Changed a leaking radiator and decided to completely drain the system, and refill it. Im assuming there is an air lock because the system will not take all the coolant. I have checked and verified that everything is in working order (heater core, water pump, thermostat, fan, hoses).

I´ve tried to burp the system on and off for two weeks now, and no luck.
is there something I´m overlooking?

It drives ok at slow speed, the temp gauge goes into the red when accelerating (though it never spills over) and theres no heat in the cabin.

Im about to see if a shop can do a drain and flush and get it working again but I wanted to ask here first to see if anyone had any insight


Edited to add: I did everything according to the Haynes Manual

 

It would help if we didn't have to guess what you're working on.

Find the steepest grade you can and park the vehicle with the front facing uphill. Run the engine at a fast idle until the thermostat opens and that will usually clear out air bubbles.

If that doesn't work, the lines will need to be opened.

 

Sorry it is a 2010 Ford Explorer

Here is everything thing I have done from the start:
Replaced Radiator.
Replaced Thermostat.
Drain and flush and re-service.
Checked for leaks out of the water pump weep hole (none) and operation of pump, the gets hot and I feel water go through it when the thermostat opens.
Check the radiator cap for pressure, it opens at 20psi and hold between 17-19psi. Replaced radiator cap anyway.
Removed supply hose and ran coolant to help purge trapped air.
Ran water through the supply and return hoses on the heater core. On the front and rear.
Check operation of heater control valve, works.
Turned vehicle on while watching the exhaust pipe, a small amount of water on initial start up in the morning but no smoke.

Problems still occurring:
Drive vehicle it over heats but returns to normal at idle I also get the coolant light that extinguishes when the car returns to idle. Even though it says its overheating the car has not pushed coolant into the expansion tank.
The car will not take any more coolant, and only overheats after the fan comes on. And still no heat.

My background is no car experience, I am a helicopter mechanic and if this was an I would be done by now. SO please take it easy on a rookie shade tree mechanic.

Should add, 4.0L engine, no oil in water after flush and the engine oil looks like engine oil not milky.