Bardahl Radiator Stop Leak SpecificationsPackaged in a 500 ml bottle Bardahl Radiator Stop Leak acts quickly and durably on leaks and cracks in the cooling system and heater radiator without requiring dismantling. It also prevents the formation of rust and scale and ensures perfect circulation of fluids to prevent engine overheating. Its special formula is safe for hoses seals and all metals in the cooling and heating system.How to use: With the engine warm and switched off turn the heater to the maximum position. Shake the bottle vigorously then pour the contents into the radiator or expansion tank without exceeding the maximum level. Run the engine at idle or drive normally for 15 minutes keeping the heater in the maximum position.