The Class excavators, including the ZX270-3, ZX270LC-3, ZX280LC-3, and ZX280LCN-3 models, represent robust and reliable machinery engineered for demanding construction and earthmoving applications. Powered by a Hino J07E-DU 6.37 L diesel engine delivering 149 kW (200 hp), these excavators feature a hydrostatic travel and swing system for efficient operation. With an operating weight of approximately 26,000 kg and an overall width of 3.19 meters, they are designed for stability and performance in a variety of challenging environments. This comprehensive Service Repair Workshop Manual provides detailed guidance for the maintenance and repair of the Class excavators. It covers a wide range of essential procedures, including step-by-step instructions, diagrams, illustrations, and wiring schematics for critical components such as the swing device, travel motor, pump device, and control valve. The manual also addresses air filter replacement, hydraulic system service, and safety precautions, making it an invaluable resource for mechanics, independent auto service professionals, and vehicle owners seeking to ensure the optimal performance and longevity of their equipment.