This manual covers the Hitachi EX270LC-5 Excavator, designed for demanding operational environments. Engineered for reliability and efficiency, this model features robust construction and advanced systems to ensure optimal performance. The EX270LC-5 is equipped with ISUZU A-6BG1TQA, A-6BG1 TQA01, or HINO H07D engine options, providing the power and durability required for extensive use in construction and heavy-duty applications. Its design prioritizes operator comfort and ease of maintenance, reflecting Hitachi's commitment to quality and innovation in heavy machinery. The purpose of this comprehensive service repair manual is to provide detailed guidance for the maintenance, troubleshooting, and repair of the Hitachi EX270LC-5 Excavator. It includes in-depth sections on general information, system and component operation, operational performance testing, and troubleshooting. Furthermore, it details hydraulic and electrical circuits, connectors, and harness information, alongside specific procedures for the upperstructure, undercarriage, front attachment, and engine. This manual is an essential resource for owners, mechanics, and technicians, offering step-by-step instructions, critical notes, and detailed illustrations to ensure the vehicle remains in optimal working condition.