How to Bleed Air from Your Cooling System

If your car is running hot, you can bleed air from the cooling system to release air pockets trapped in the lines and radiator. These air pockets can cause overheating by impeding the flow of coolant through the system. They also make the coolant level appear to be high, when in fact it is just air pushing the coolant level up. Here is a way to bleed air from your cooling system and make sure your radiator functions properly .

Step 1 – Mix Water and Antifreeze

Make a mixture of 1 part water and 1 part antifreeze. Put it into the radiator, making sure to fill it up to the rim. Fill the coolant or overflow reservoir with the same water and antifreeze mixture.

Step 2 – Turn On the Engine

Leave the radiator cap off. Turn on your engine and let it run until the radiator bleeds out air. You'll observe the coolant level drop and see air bubble escaping from the radiator, and perhaps hear it gurgle.

Step 3 – Observe the Temperature

Observe the temperature gauge as this is happening. Expect the temperature gauge go down to normal or close to normal. This process is helping the radiator feed the coolant more evenly, making the system function properly. It is not air circulating around your radiator anymore but coolant.

Step 4 – Refill the Radiator

Refill the radiator once again, and the coolant reservoir. It will be as much as half empty, since earlier it was simply air that made it seam full. Fill to the top.

Step 5 – Replace the Radiator Cap

Seal the radiator with the cap. This will keep the air out of the system. Your car’s temperature gauge should be back to normal and you now know that it is coolant filling your radiator and coolant reservoir and not air pockets.