This manual covers the Hitachi EX120-5 Excavator, designed for robust performance and reliability in various operational environments. Featuring ISUZU A-6BG1TQA and A-6BG1 TQA01 engines, this model exemplifies Hitachi's commitment to engineering excellence. It is built to handle demanding tasks, offering operators and owners a dependable and efficient machine for construction and heavy-duty applications. The EX120-5 is engineered for durability, ensuring consistent productivity and a long service life. This comprehensive workshop repair service manual provides detailed information for the maintenance, servicing, and troubleshooting of your Hitachi EX120-5 Excavator. It includes technical manuals covering operational principles and troubleshooting, a workshop manual detailing general information, upperstructure, undercarriage, front attachment, and engine components, as well as circuit diagrams and harness information. This resource is designed to assist owners, mechanics, and technicians in performing repairs and maintenance accurately and efficiently, ensuring the optimal performance and longevity of the equipment.