If your vehicle's coolant is a murky brown and the radiator is covered in rust, you may need a product such as Prestone Super Radiator Flush. This radiator cleaning fluid is composed of detergents that will remove rust, grease, oil and other residues when run through the vehicle's cooling system.
Turn off the engine and allow it to cool. Remove the radiator cap and loosen the radiator drain cock. Drain all the old fluid from the radiator. Close the drain cock.
Pour the contents of a 22-ounce bottle of Prestone Flush into the radiator. For radiators with a larger capacity than 12 quarts, use two bottles. Install the radiator cap.
Adjust the heater to its highest setting. Run the engine for 10 minutes after reaching normal operating temperature.
Turn off the engine and allow it to cool. Remove the radiator cap and loosen the radiator drain cock. Drain all the Prestone Flush from the radiator. Close the drain cock.
Refill the radiator with clean water. Install the radiator cap. Run the engine for 10 minutes after reaching normal operating temperature. Turn off the engine and allow it to cool. Remove the radiator cap and loosen the radiator drain cock. Drain all the water from the radiator. Close the drain cock.
Fill the radiator with a mixture of 50 to 70 percent coolant and water. Top it off with water. If there is a coolant reservoir, drain it and rinse it out. Add the coolant mixture up to the fill line. Install the radiator cap. Run the engine for 20 minutes.
