This manual covers the Hitachi EX230LC-5, EX270-5, and EX270LC-5 Excavator models, equipped with ISUZU A-6BG1TQA, A-6BG1 TQA01, or HINO H07D engines. These excavators are engineered for demanding operational environments, offering robust performance and reliability. Their design prioritizes efficiency and durability, making them suitable for a wide range of construction and heavy-duty applications. This comprehensive guide provides access to factory-level information, ensuring owners and operators can understand and maintain these powerful machines. The purpose of this service manual is to provide detailed instructions and technical specifications for the maintenance, repair, and troubleshooting of the Hitachi EX230LC-5, EX270-5, and EX270LC-5 Excavators. It includes essential information on operational principles, system overviews, component operation, performance testing, and detailed troubleshooting procedures. Furthermore, it covers hydraulic and electrical circuits, connectors, harness diagrams, and workshop procedures for the upperstructure, undercarriage, front attachment, and engine. This manual is designed to empower users with the knowledge to perform necessary service tasks accurately and efficiently.