The Hitachi Zaxis ZX 225USLC-3 is a robust excavator from the Zaxis 3 generation, engineered for demanding construction and earthmoving applications. This model, powered by an Isuzu AA-6HK1XDI diesel engine with a displacement of 7.8 liters, delivers 120 kW of gross power at 2000 rpm. Its design emphasizes reliability and operational efficiency, featuring a hydrostatic transmission and a substantial operating weight of 22,700 kg. With impressive digging capabilities, including a maximum digging depth of 6700 mm and a reach of 10110 mm, the ZX 225USLC-3 is built to perform in challenging environments. This Workshop Service Manual provides comprehensive information for the maintenance and repair of the Hitachi Zaxis ZX 225USLC-3 excavator. It covers essential areas such as detailed engine specifications, hydrostatic transmission operation, fluid capacities for engine oil, hydraulic systems, fuel, and coolant, as well as critical service schedules for filter replacements. The manual is designed to assist owners, mechanics, and technicians in ensuring the optimal performance, longevity, and safety of the equipment through accurate procedures and technical data.