The Hitachi ZX40U-3 is a compact excavator from the U-3 Series, engineered for robust performance and reliability in demanding work environments. This tracked vehicle features a powerful Yanmar 3TNV88 diesel engine, delivering a gross power of 37.7 kW (50.6 hp) and a net power of 35.7 kW (47.9 hp). With a hydrostatic transmission and a substantial operating weight of 3900 kg (8598 lb), the ZX40U-3 is designed for versatility and efficiency in construction, landscaping, and various utility applications. Its compact dimensions, including a width over tracks of 1740 mm (5 ft 9 in) and a tail swing radius of 1270 mm (4 ft 2 in), allow for operation in confined spaces. This Service Repair Manual provides comprehensive information for the Hitachi ZX40U-3, covering all aspects of service and repair in English. It details essential maintenance procedures, including fluid capacities and service intervals for engine oil and hydraulic filters, alongside technical specifications for the engine, hydraulic system, and working equipment. The manual also includes information on troubleshooting, safety guidelines, and detailed specifications for dimensions and undercarriage components. This resource is invaluable for owners, mechanics, and technicians seeking to maintain the optimal performance and longevity of their ZX40U-3 excavator.