How to Bleed a Truck Radiator

Although engines are commonly thought of as devices that are internally sealed, no engine is completely free from the outside environment. Minute leaks, undetectable to the naked eye, commonly result in air entering the engine where it should not. Air pockets can develop within the passageways used to transport antifreeze throughout the engine. Over time, these air pockets can grow and severely restrict the ability of the antifreeze to cool the engine. When this occurs, it is time to bleed the radiator. Bleeding a truck's radiator is similar to bleeding the radiator of a passenger vehicle, with the exception that the front of the truck must be raised.

Things You'll Need

• Floor jack
• Jack stands
• Antifreeze

Instructions

1. Place a floor jack underneath the frame at the front of the truck, then use the jack to lift the front of the truck so that the top of the radiator is above the top of the engine. Place a pair of jack stands under the frame at the front of the truck, then lower the truck so that the weight of the truck is supported by the jack stands.

2. Open the hood and remove the truck's radiator cap. Most caps can be removed by pressing down on the cap while simultaneously twisting the cap in a counterclockwise direction, although some caps have a lever in the center of the cap that must first be lifted up.

3. Start the truck's engine and allow it to reach normal operating temperature. Once the engine is warm, the truck's thermostat will open, allowing antifreeze from the radiator to circulate throughout the engine. The antifreeze level in the radiator will go down once the thermostat opens. As the engine runs, air pockets will escape through the top of the radiator.

4. Fill the radiator with antifreeze while the engine is running. The additional antifreeze is necessary to fill the void left by the air pockets.

5. Turn the truck's engine off and allow it to cool.

6. Twist the radiator cap back onto the radiator.

7. Lift the front of the truck with the floor jack to remove the jack stands, then lower the truck to the ground to complete the process.