NO it uses freon r-134 for newer models and r-12 for older cars.
R134a
No
YesYes
It uses R134 refrigerant.
No, they have different boiling points and heat transfer capacities.
You will have to replace the refrigerant, but not the engine coolant.
The coolant goes into the reservoir only that says coolant. You don't put it in the radiator.
r-134
One way to tell if you're low on coolant on a central AC unit is to feel the air coming out of the vents. If the air is warm or room temperature, it is a sign that you are low on coolant.
To charge the AC on a 2006 5.3L express van you locate the AC unit under the hood. The owners manual will have diagrams on the engine parts and the type of coolant needed to recharge the AC. You follow the instructions on the coolant.
The heater core is leaking coolant.
R134a