The Engine coolant radiator burp fill procedure
From one of the Ford Service publications.
Radiator Re-Fill Procedure
Re-fill the radiator with a 50/50 Mix of Gold Anti-Freeze and Distilled Water following the procedure below to burp air from cooling system. Re-check Radiator Fluid Level. Repeat as necessary to ensure proper engine cooling.
Filling — Cobra without RADKITPLUS*CAUTION: Vehicle cooling systems are filled with Motorcraft Premium Gold Engine Coolant VC-7-A (in Oregon VC-7-B) or equivalent meeting Ford specification WSS-M97B51-A1 (yellow color). Always fill the cooling system with the same coolant that is present in the system. Do not mix coolant types.
*CAUTION: Engine coolant provides freeze protection, boil protection, cooling efficiency, and corrosion protection to the engine and cooling components. In order to obtain these protections, the engine coolant must be maintained at the correct concentration and fluid level in the degas bottle.
When adding engine coolant, use a 50/50 mixture of engine coolant and deionized water.
To maintain the integrity of the coolant and the cooling system:
Add Motorcraft Premium Gold Engine Coolant VC-7-A (in Oregon VC-7-B) or equivalent meeting Ford specification WSS-M97B51-A1 (yellow color). Use the same coolant that was drained from the cooling system. Do not mix coolant types.
Do not add/mix orange-colored Motorcraft Speciality Orange Engine Coolant VC-2 or equivalent meeting Ford specification WSS-M97B44-D. Mixing coolants may degrade the coolant's corrosion protection.
Do not add alcohol, methanol, or brine, or any engine coolants mixed with alcohol or methanol antifreeze. These can cause engine damage from overheating or freezing.
Do not mix with recycled coolant unless it meets the requirements of Ford specification WSS-M97B51-A1. Not all coolant recycling processes meet these Ford specifications. Use of such coolants can harm the engine and cooling system components.
NOTE: The addition of Motorcraft Cooling System Stop Leak Pellets, VC-6, darkens Motorcraft Premium Gold Engine Coolant from yellow to golden tan.
Check all hose clamps for correct tightness. Make sure the radiator drain**** is closed.
Remove the coolant bottle cap and fill the degas bottle to the add coolant line. Install the cap.
*CAUTION: Do not fill the cooling system through the reservoir only (coolant will not enter the engine), only the reservoir and the radiator will be filled and engine overheating will occur.Remove the fill plug in the crossover tube on top of the engine.
Using a funnel, add coolant to the crossover port, keeping the level of coolant in the funnel at 1/4 full.
Squeeze the 2 large upper cooling system hoses 5 times. Bubbles may appear in the funnel as air exits the system.
Start the engine and run for 5 minutes while monitoring the coolant in the funnel.
A sudden drop in the funnel level indicates the elimination of air in the system.
Shut off the engine and let it cool for 10 minutes.
Crack open the degas bottle cap enough to allow the coolant level in the funnel to drop to within 1 inch of the bottom of the funnel.
Tighten the cap.
Remove the funnel and install the fill plug in the crossover tube.
Add coolant in the degas bottle to the full coolant line.
Repeat the fill procedure after a few heat/drive cycles to be extra sure.
I'd like to add when burping the coolant system squeezing the ALL the hoses and revving the motor a little will help push air out as well