The Fiat 55-66 DT LP Tractor, part of the renowned Fiat 66 Series, represents a robust and versatile medium-horsepower agricultural machine. Produced likely during the late 1980s and 1990s, this 4-wheel-drive tractor is powered by a dependable naturally aspirated diesel engine, delivering approximately 55 horsepower. Its engineering is characterized by the durability and reliability for which Fiat Trattori is known, making it a valuable asset for farming operations. The model's design emphasizes practicality and operational efficiency, featuring a synchronized manual gearbox with multiple forward and reverse gears, a standard power take-off (PTO), and a functional operator station. This Service Repair Workshop Manual provides comprehensive and in-depth technical information for the Fiat 55-66 DT LP Tractor. It is meticulously structured to guide mechanics, farmers, and technicians through all aspects of maintenance, diagnosis, and repair. Coverage includes detailed procedures for the engine, transmission, drivetrain, hydraulics, braking, electrical, cooling, fuel, and steering systems. The manual also encompasses routine maintenance, complex overhauls, troubleshooting guides, and essential technical specifications, ensuring that users have the authoritative knowledge required to keep this dependable tractor in optimal working condition.