This Service Repair Workshop Manual covers the Hitachi Zaxis ZX 120-3 excavator, a piece of heavy construction equipment designed for demanding operational environments. Engineered for reliability and performance, the Zaxis ZX 120-3 is built with robust diesel engine technology to ensure efficient operation. This manual provides comprehensive information to support the upkeep and functionality of this powerful machine, making it an essential resource for owners and operators. The purpose of this manual is to provide detailed guidance for the service, maintenance, and troubleshooting of the Hitachi Zaxis ZX 120-3 excavator. It includes step-by-step instructions, supported by high-quality diagrams and detailed exploded illustrations, to facilitate complete disassembly and reassembly. This resource is intended for both do-it-yourself enthusiasts and experienced mechanics, offering clear procedures to ensure jobs are completed correctly and efficiently, thereby maintaining the optimal working condition of the equipment.