HEAVY DUTY RADIATOR STOP LEAK AND FLUSH COMBO K2 HEAVY DUTY RADIATOR STOP LEAK K2 RADIATOR STOP LEAK is the highest quality product for sealing radiators. It seals even large leaks quickly and effectively. It is perfect for removing leaks caused by stone chipping, vibrations or other mechanical damage. It can be used in all types of coolants. It is miscible with any type of coolant, including the New Productest long life types. It does not obstruct the circulation of the fluid inside the system. Safe for the heater and other elements of the cooling system. 400ml K2 Car Radiator / Heater Flush REMOVES IMPURITIES Effectively rinses heavily soiled coolers. Within 15 minutes, it removes rust, limescale and other impurities. Regular use with each liquid change allows you to .