This workshop service repair manual covers Volvo Penta MD21A, AQD21A, MD32A, and AQD32A marine diesel engines. These engines are engineered for reliable marine propulsion, offering robust performance and durability. Designed for a variety of maritime applications, these diesel engines represent a commitment to quality and operational efficiency in marine environments. This comprehensive manual provides detailed, step-by-step instructions for the complete disassembly and reassembly of these engines, ensuring proper service and repair. It includes hundreds of photos and illustrations to guide both do-it-yourself enthusiasts and experienced mechanics through every maintenance procedure and troubleshooting scenario. The manual is designed to help users maintain their Volvo Penta engines in optimal condition, ensuring longevity and peak performance.