This manual covers the Hitachi EX270-5 Excavator, designed for demanding operational environments. Featuring robust engineering and reliable performance, this excavator is equipped with ISUZU A-6BG1TQA, A-6BG1 TQA01, or HINO H07D engine options. Its construction emphasizes durability and efficiency, making it a capable machine for various construction and heavy-duty tasks. This comprehensive service repair manual provides detailed information for maintaining and repairing the Hitachi EX270-5 Excavator. It includes operational principles, troubleshooting guides, system and component operation, performance testing, and detailed workshop procedures for the upper structure, undercarriage, front attachment, and engine. Circuit diagrams for hydraulic and electrical systems, along with harness and connector information, are also provided to assist owners, mechanics, and technicians in diagnosing and resolving issues effectively.