This manual covers the Hitachi Zaxis 225 US 3 excavator, a robust piece of equipment designed for demanding construction and earthmoving applications. Known for its reliable diesel engine and advanced hydrostatic drive system, this model offers efficient operation and precise control. The Zaxis 225 US 3 is engineered with operator comfort and safety in mind, featuring a pressurized cabin that is ROPS/FOPS compliant. Its substantial operating weight, typically ranging from 22,000 to 25,000 kg, underscores its capability for heavy-duty tasks, while its sealed and lubricated track components ensure durability in challenging environments. The purpose of this workshop service repair manual is to provide comprehensive guidance for the maintenance, repair, and technical understanding of the Hitachi Zaxis 225 US 3. It details essential procedures, diagnostic information, and technical specifications necessary for owners, mechanics, and technicians. Key areas covered include engine operation, hydraulic system maintenance, drivetrain servicing, and undercarriage care. By following the instructions and adhering to the recommended intervals outlined within this manual, users can ensure the optimal performance, longevity, and safety of their equipment.