This workshop service repair manual covers the Hitachi Zaxis 3 Series excavator, specifically models within the Zaxis 240-3 series. Engineered for demanding construction and earthmoving applications, this excavator is powered by a robust Cummins B5.9-C diesel engine, delivering 124 kW (166 hp) and 673 Nm (497 lb-ft) of torque. Its hydrostatic transmission and dual tracked drive motors provide reliable power and maneuverability, with an operating weight of 23,500 kg (51,800 lbs). Key dimensions include a length over tracks of 9,525 mm (31 ft 3 in) and a width over tracks of 2,990 mm (9 ft 10 in), facilitating operation in various job sites. The machine is designed for efficiency and durability in heavy-duty tasks. This comprehensive manual provides essential information for the maintenance, repair, and technical understanding of the Hitachi Zaxis 240-3 excavator. It details critical maintenance procedures, including fluid capacities for the engine, hydraulic system, coolant, swing system, and final drives. Technical specifications cover engine details, transmission, dimensions, and hydraulic system performance, such as main and pilot pump flow rates and maximum system relief pressure. Safety guidelines and troubleshooting information are also included to assist owners, mechanics, and technicians in ensuring the optimal performance and longevity of the equipment.