How to Get Air Out of a Truck Radiator
- 1). Allow the cooling system to reach ambient temperature. To do this, simply turn off the truck's engine for at least one hour.
- 2). Open the radiator cap and set aside.
- 3). Turn the truck engine back on.
- 4). Turn the heat to "Max". This will allow the coolant to flow through the heater core, so that all air pockets will be removed.
- 5). Squeeze the upper radiator hose while the truck engine is on. This method is called "gulping," and helps in eliminating air pockets.
- 6). Rev the engine up to 2,000 RPMs and hold for about 15 seconds, so that the cooling pump pumps fluid through the system at a faster rate than when engine is idled. Fluid will be forced through the system and will bring all the air pockets up to the radiator, thus purging the air out of the radiator. Repeat this step about 2 to 3 times.
- 7). Close the radiator cap.