Bar's Leak 11 oz. Cooling System Sealer mixes with all quality antifreeze and is harmless to rubber, aluminum, and other metals. The pellet-sized sealer dissolves to form a lasting internal and external seal in engine blocks and heads, radiator and heater core, head gaskets, hose connections, and freeze plugs. It's the perfect solution for stopping leaks and keeping your engine running smoothly.

• 11 oz.
• Mixes with all quality antifreeze
• Harmless to rubber, aluminum, and other metals
• Pellet-sized sealer dissolves to form a lasting internal and external seal in engine blocks and heads, radiator and heater core, head gaskets, hose connections, and freeze plugs.