This comprehensive service and repair manual is specifically designed for the Komatsu PC400-6 and PC400LC-6 Custom hydraulic excavators with serial numbers 30001 and up, covering models manufactured from 2008 onwards. It serves as an essential resource for technicians and mechanics involved in maintaining and repairing these powerful machines. The manual provides detailed information on every aspect of the excavators, from basic operation and maintenance procedures to complex troubleshooting and repair techniques. It includes detailed diagrams, illustrations, and step-by-step instructions to guide users through various tasks. The manual covers a wide range of topics, including: * **Engine:** Detailed information on the engine, including its components, operation, maintenance, and troubleshooting. * **Hydraulic System:** In-depth coverage of the hydraulic system, encompassing pumps, valves, cylinders, and other related components. * **Electrical System:** Comprehensive explanations of the electrical system, wiring diagrams, and troubleshooting procedures. * **Undercarriage:** Detailed descriptions of the undercarriage components, including tracks, rollers, and sprockets. * **Operator's Cab:** Information on the operator's cab, controls, and safety features. * **Troubleshooting and Repair Procedures:** Extensive guidance on diagnosing and resolving a wide range of issues that may arise with the excavator. * **Specifications and Technical Data:** Complete specifications and technical data for the PC400-6 and PC400LC-6 Custom models. This manual is an invaluable tool for anyone working with Komatsu PC400-6 and PC400LC-6 Custom excavators. It empowers technicians to perform efficient maintenance, diagnose problems accurately, and complete repairs effectively.