This manual covers the Komatsu S6D114E-1, SA6D114E-1, and SAA6D114E-1 Series Engines. These internal combustion engines are designed for robust performance and reliability in demanding applications. This comprehensive guide provides essential information for understanding, maintaining, and repairing these powerful Komatsu engines, ensuring their continued optimal operation. The purpose of this 975-page English-language Service Repair Manual is to provide detailed instructions for the service, repair, maintenance, and troubleshooting of the specified Komatsu engines. It includes step-by-step repair procedures, engine disassembly and assembly instructions, electrical diagrams, and troubleshooting logic. Coverage extends to critical systems such as fuel, lubrication, cooling, air intake and exhaust, and electrical components, alongside detailed information on engine components and testing procedures, all supported by real photo illustrations, schemes, and exploded diagrams.