This service and repair workshop manual covers the David Brown AD4 25 and CAD4 30 engine models. Designed for comprehensive guidance, these engines are recognized for their robust engineering and reliability, making them suitable for a wide range of demanding applications. The manual details the advanced features and construction that contribute to their dependable performance in various operational environments. This manual serves as an essential resource for maintaining and repairing your David Brown engine. It provides detailed instructions for all service and repair procedures, covering everything from routine maintenance to complex troubleshooting. Mechanics and technicians worldwide rely on this manual for accurate technical specifications, safety guidelines, and step-by-step repair processes, ensuring optimal performance and longevity of the engine.