This manual provides comprehensive service and repair information for the Hino W04C-T marine engine. Designed for reliability and performance, the W04C-T engine is a robust unit engineered for demanding marine applications. Its construction emphasizes durability and efficiency, making it a trusted choice for various vessel types. This guide ensures that owners and operators can maintain the engine's peak operational condition. The purpose of this manual is to serve as an authoritative resource for all maintenance, repair, and diagnostic procedures related to the Hino W04C-T marine engine. It covers essential topics including engine identification, general precautions, maintenance schedules, detailed inspection and repair procedures for major components such as the engine body, fuel system, and cooling system, as well as troubleshooting guides, special tools, and servicing specifications. This document equips technicians and owners with the knowledge necessary to perform accurate diagnostics and effective repairs, ensuring the longevity and optimal performance of the engine.