Head Gasket Sealant is NOT COMPATIBLE with antifreeze and must only be added to the cooling system after ALL ANTIFREEZE has been flushed and removed. Seals cracked cylinder heads and blocks. Dual Action 2 Part Formula — LIQUID CERAMIC: Liquid penetrates large and small leaks to form a seal actually harder than the original head gasket — REINFORCED FIBERS: Fiber additives lock together with liquid to increase strength and promote a permanent seal.
