The Komatsu PC300HD-8 is a robust hydraulic excavator designed for demanding construction and earthmoving applications. Built with Komatsu's renowned engineering for reliability and performance, this machine features a powerful Komatsu SAA6D114E-3 engine, producing 193 kW (259 HP) and meeting Tier 3 / EU Stage IIIA emission standards. Its hydrostatic transmission ensures efficient power delivery, while its substantial operating weight of approximately 30,750 kg and impressive digging capabilities, including a maximum digging depth of 7.13 meters, make it suitable for a wide range of heavy-duty tasks. This Workshop Service Repair Manual provides comprehensive information for the Komatsu PC300HD-8, covering serial numbers A87001 and up. It details essential maintenance procedures, troubleshooting guidance, and technical specifications required to keep the excavator operating at peak efficiency. Owners, technicians, and mechanics will find detailed instructions on lubrication, filter changes, and system specifications, enabling effective upkeep and repair to ensure the longevity and optimal performance of the machine.