The Hitachi Zaxis 3 series excavators, including models Zaxis 200-3, 210H-3, 210K-3, 210LCN-3, and 240N-3, represent a significant advancement in heavy machinery, built for demanding construction and excavation tasks. These machines are engineered for exceptional reliability and performance, featuring robust construction and advanced hydraulic systems. Powered by efficient Cummins QSB4.5 or Isuzu AH-4HK1X engines, they deliver substantial power output for their operating weight, which ranges from approximately 20,000 to 24,000 kg. With hydrostatic swing and travel systems offering two speed ranges and impressive digging depths up to 7,000 mm, these excavators are designed to maximize productivity and operational efficiency in diverse work environments. This Service Repair Workshop Manual provides comprehensive guidance for the maintenance, repair, and technical understanding of the Hitachi Zaxis 3 series excavators. It covers essential areas such as detailed engine specifications for both Cummins and Isuzu power units, including displacement and power outputs, as well as critical fluid capacities for engine oil, hydraulic oil, and coolant. Furthermore, the manual outlines recommended service intervals for key components like engine oil filters and hydraulic filters. It also includes vital information on dimensions, performance metrics such as digging depth and reach, and troubleshooting procedures, equipping owners, technicians, and mechanics with the necessary knowledge to ensure optimal performance and longevity of their equipment.