The Hitachi Zaxis 225 USR 3, part of the USR Series, represents a robust construction machine designed for demanding operational environments. Engineered with a focus on reliability and efficiency, this model features a powerful diesel engine and a sophisticated hydrostatic drive system, including a hydrostatic swing drive and dual-speed travel transmission. Its operational capabilities are enhanced by hydraulic pilot controls and selectable power and economy modes, allowing for optimized performance. The machine is equipped with a ROPS compliant cab for operator safety and includes an emergency stop function. With an operating weight ranging from approximately 21,600 to 23,400 kg, the Zaxis 225 USR 3 is built for substantial work capacity. This Workshop Service Repair Manual provides comprehensive guidance for the Hitachi Zaxis 225 USR 3. It is intended for mechanical technicians and covers essential maintenance procedures, including recommended engine oil type and capacity, hydraulic oil capacity, fuel tank capacity, and coolant specifications. The manual details routine servicing, greasing frequencies, and information on key components such as variable displacement piston pumps. Additionally, it offers insights into troubleshooting and technical specifications necessary for effective repair and upkeep. By utilizing this manual, owners and service personnel can ensure the optimal performance, longevity, and safe operation of their Hitachi construction equipment.