This workshop service repair manual covers the Hitachi Zaxis 250 H-3 excavator, a robust piece of machinery designed for demanding construction and earthmoving applications. Engineered for reliability and performance, this model typically features a powerful diesel engine, a hydrostatic transmission for precise control, and an operating weight of approximately 25-26 metric tons. Its substantial digging depth and reach, coupled with a generous bucket capacity, make it a versatile tool for a wide range of tasks. The H-3 generation represents a significant advancement in Hitachi's excavator technology, focusing on operator efficiency and durability in challenging environments. The purpose of this manual is to provide comprehensive guidance for the maintenance, repair, and technical understanding of the Hitachi Zaxis 250 H-3. It details essential procedures for mechanical technicians, covering scheduled maintenance, fluid capacities, lubrication, and diagnostic troubleshooting. Included are technical specifications for the powertrain, chassis, and performance capabilities, such as engine displacement, hydraulic oil capacity, maximum digging depth, and ground pressure. This document serves as an indispensable resource for ensuring the optimal performance, longevity, and safe operation of the Zaxis 250 H-3 excavator.