How to Bleed the Radiator in Car

If your car temperature keeps on rising steadily it’s time to have a look at its radiator. Your coolant level may be low or there might be some rust or other debris inside the radiator that is causing problems with the proper circulation of coolant around the water body of the engine. Or, there might be air trapped in the radiator of the car which causes the performance of the cooling system to drop. It prevents coolant from entering into holes and small tubes in the engine, which in turn causes the temperature of the engine to rise constantly.


  • 1

    Open the bleeder valve if present

    Some automobiles have a radiator bleeder valve, which is present for the purpose of removing trapped air in the radiator. The air is mostly trapped in the upper section of the radiator since air is lighter than water and coolant, so this valve is usually found at the top section of the radiator.

  • 2

    Raise the car

    This is very crude way to bleed the radiator dry of air as elevating the car from the front side raises your radiator to the extent that it is higher than the rest of the cooling system. This process puts pressure on the air pockets inside the radiator and causes them to be released to the atmosphere.

  • 3

    Take off the radiator cap and turn on the engine

    One of the simplest ways to bleed your car engine is to take off the radiator cap and then fire the ignition. Some coolant may pop out of the cap, do not panic.

    Keep the engine running for about 15-20 minutes as your engine needs a certain amount of time to generate enough heat to push out the trapped air in your cooling system. Keep a bottle of coolant in reserve as some coolant will be wasted during this procedure.

  • 4

    Flushing the container

    Flushing the radiator is a good way to refresh the coolant inside the cooling system. It also helps prolong the life of the radiator as this removes dirt and other debris from the chamber. Put a bucket underneath the radiator and use a wrench to loosen the drain hole under the radiator.

    Take out the bolt completely and coolant will start gushing out of the hole. Give it about 15 minutes to drain out completely. Put the drain bolt back in its place and add fresh coolant to the radiator.

Leave a Reply

Your email address will not be published. Required fields are marked *

2 × five =