Do you notice small air bubbles in the coolant recovery tank when you first start the engine, this would indicate a possible blown head gasket, and these are known for doing just that. If not then these things can be a real bear getting the air out, I start by filling the radiator through the upper hose on the engine side, when it takes all it can quickly shove it back on and tighten the clamp, then fill the recovery tank and raise the passenger side at least 6 inches, a car ramp is just right, start the engine and keep adding fluid as it takes it, when it stops taking fluid put the cap on and shut it off and wait 15 minutes, then check level in the recovery tank, if low carefully remove the cap as there might be pressure there, if there is too much pressure wait a while longer, when pressure drops enough for safe removal, top off the system and restart watch the level as the engine warms up, if it threatens to run out of the tank reinstall the cap and let the engine continue to run until the thermostat opens, and that should take care of any air pockets. Then make sure the cooling fans operate properly.
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