This text is intended to provide students with basic information on conducting preventive maintenance on agricultural machinery. The following topics are covered in the individual chapters: the importance of preventive maintenance and recommended service intervals; engine intake and exhaust systems (air cleaners, turbochargers, intake and exhaust valves, exhaust manifolds and mufflers, crankcase ventilation, and testing procedures); engine fuel systems (fuel selection, procedures for refueling machines, fuel systems, and engine governors); lubricating systems (operating and servicing lubrication systems and selecting engine oils); engine cooling systems; engine electrical systems; power trains; hydraulic systems; other components (operator's cabs, manual steering, steering axles and wheels, manual brakes, tires, grease fittings, belt and chain drives, gear drives, and lighting and accessories); tune-up and storage (engine tune-up, visual inspection, dynamometer tests, engine tune-up charts, and machine storage); and troubleshooting procedures. Concluding each chapter are a chapter summary and a set of self-test questions. Answers to the questions are also provided. (MN)