ACDelco RTV Engine Sealant 12378521

The ACDelco 12378521 RTV Engine Sealant is the sealant used in GM engine plants. Reseal your engine components with the same high-quality sealer used in the GM Production Line. ACDelco RTV Engine Sealant is a one-component, room-temperature vulcanizing (RTV) sealant. It is a high viscosity product that cures when exposed to air. The cured material has superior adhesion and elongation properties and is resistant to engine oils and coolants. It is also oxygen sensor safe and will not corrode metal surfaces.