This injector sleeve seats the fuel injector into the cylinder head, forming the seal that isolates combustion pressure from the cooling system. It is a bushing-type component located in the engine block, where it guides the injector body and prevents blow-by of hot gases into the coolant jacket. A worn or cracked sleeve causes compression loss into the cooling circuit, visible as bubbles in the coolant or a hard-start condition. As an original AGCO part, the sleeve is machined to the same interference fit and seal-groove depth as the factory component, so no additional shimming or sealant is required for correct seating. On installation, clean the bore thoroughly and apply a light coat of lubricant to the outer diameter before pressing.