BlueDevil Coolant Stop Leak is an easy to use, do it yourself formula that will seal leaks throughout your vehicles cooling system stopping that antifreeze loss and keep your vehicle in safe operating condition. BlueDevil Coolant Stop Leak is compatible in gasoline and diesel engines, it’s safe for Northstar engines and guaranteed to help seal any leaks in and around your cooling system. It contains no solid or particulate matter, and will not clog or harm your engine. It bonds to various, different materials such as metal, aluminum, cast, alloy, or plastic.