The Hitachi ZAXIS ZX135US Crawler Excavator is engineered for demanding construction and earthmoving applications. This robust machine features a powerful Isuzu AI-4HK1X engine, delivering 73.1 kW (98 hp) of net power and 367 Nm (271 lb-ft) of torque, ensuring efficient operation. With a hydrostatic transmission, it offers precise control and versatile travel speeds up to 5.0 km/h (3.1 mph). Its compact design, with an operating weight of 13,800 kg (30,420 lb) and a width of 2,590 mm (8 ft 6 in), allows for operation in confined spaces while maintaining impressive digging capabilities, including a maximum digging reach of 9,470 mm (31 ft 1 in). This Service Repair Manual provides comprehensive guidance for the Hitachi ZAXIS ZX135US Crawler Excavator. It covers essential maintenance procedures, detailed troubleshooting steps, and critical technical specifications to ensure optimal performance and longevity. Owners, mechanics, and technicians will find detailed information on engine systems, hydraulics, drivetrain, lubrication, and undercarriage components. Adhering to the guidelines within this manual will facilitate proper upkeep, efficient repairs, and safe operation of the equipment.