This Service Repair Manual covers the JCB 508-40 Telescopic Handler and the JCB 510-40 Telescopic Handler, with serial numbers ranging from 562601 to 579365 for the 508-40 and 564542 to 579365 for the 510-40. These machines are engineered for demanding operational environments, offering robust performance and reliability. The manual provides comprehensive information essential for understanding and maintaining these telescopic handlers, ensuring their optimal function and longevity in various industrial and construction applications. This manual is designed to be a complete resource for owners, technicians, and mechanics. It details all aspects of service and repair, including extensive coverage of general systems, hydraulics, body and framework, control systems, engine, transmission, axles, brakes, steering, and electrics. With step-by-step instructions, hundreds of photos and illustrations, and detailed service intervals and fluid capacities, this manual empowers users to perform maintenance and repairs efficiently, saving time and costs while ensuring the vehicle remains in peak operating condition.