The Fiat Trattori 540 and 540DT series tractors, produced primarily during the 1970s and 1980s, represent a significant line of utility agricultural machinery. These tractors are known for their robust diesel engines, typically from the Fiat 8045 series, offering approximately 50-60 horsepower, and are equipped with reliable manual transmissions featuring multiple gear ratios. The 540DT variant includes a four-wheel-drive system, enhancing its versatility. Designed for a range of agricultural tasks, these models are characterized by their straightforward engineering, durability, and the brand's long-standing reputation for quality in the agricultural sector. This comprehensive service and repair manual provides in-depth information for the Fiat Trattori 540 / 540DT tractors. It covers all essential systems, including detailed procedures for engine repair and overhaul, transmission and drivetrain maintenance, hydraulic system servicing, and electrical system diagnostics. The manual also includes guidance on steering, braking, cooling, fuel, exhaust, and chassis components, alongside regular maintenance schedules, fluid specifications, and troubleshooting for common issues. Designed for professional technicians and experienced mechanics, this English-language manual offers step-by-step instructions, detailed illustrations, and diagnostic flowcharts to ensure proper maintenance and repair.