Cooling System: Service and Repair

This engine does not require a cooling system bleed procedure. However, when refilling the cooling system on aluminum engines a special coolant solution along with GM coolant supplement (sealant) part No. 3634621 or equivalent must be used. Failure to add the sealant or the approved coolant solution could result in major engine damage. When refilling cooling system add three pellets of engine coolant supplement (sealant) part No. 3634621 or equivalent to lower radiator hose. Under some conditions, the ethylene glycol engine coolant is combustible. To avoid being burned, do not spill antifreeze or coolant on the exhaust system or hot engine parts.