AlumAseal is the original powder solution for stopping radiator and cooling system leaks. Simply pour in Alum seal powder and wait for the patented formula to find and seal most cooling system leaks. Alumaseal powder is safe with all types of antifreeze, prevents rust and helps lubricate the water pump. Remove radiator cap only after engine is off and cold. Turn heater control to hot. Pour contents of tube directly into radiator. Add coolant to proper level if necessary. Replace radiator cap. Drive vehicle to seal leaks.