The Hitachi Zaxis 225US is a robust excavator engineered for demanding construction and earthmoving applications. This model is built with a focus on reliability and performance, featuring a powerful Isuzu AA-6BG1T diesel engine with a displacement of 6.5 liters and a gross power output of 126 kW (169 hp). Its hydrostatic drive system and impressive digging capabilities, including a maximum digging depth of 6570 mm and a standard bucket capacity of 1.0 m³, make it a versatile tool for various job sites. The excavator's substantial operating weight of 21900 kg and overall dimensions of 9860 mm in length and 2990 mm in width underscore its heavy-duty construction. This comprehensive Service Repair Manual provides essential information for the maintenance and repair of the Hitachi Zaxis 225US excavator. It covers critical areas such as detailed engine specifications, including its water-cooled system and fluid capacities for engine oil, hydraulic tank, coolant, and fuel. The manual also outlines transmission details, lubrication intervals, and performance metrics like digging reach and swing speed. This guide is designed to assist owners, technicians, and mechanics in understanding the machine's components and ensuring its optimal performance and longevity through proper servicing and troubleshooting.