The Zetor 8011, 8045, 12011, and 12045 series tractors represent a robust line of heavy-duty agricultural machinery known for their operational reliability and durable construction. Designed for demanding farm tasks, these tractors likely hail from an era where straightforward engineering and dependable performance were paramount. With an estimated horsepower range of 80-120 HP, they offer substantial power for a variety of agricultural applications. The 40-series models likely feature 4WD capabilities, enhancing their versatility in challenging terrain. These machines are a testament to Zetor's long-standing heritage in producing capable and enduring agricultural equipment. This Factory Service Repair Manual provides comprehensive technical information essential for the maintenance and repair of Zetor 8011, 8045, 12011, and 12045 tractors. It covers a wide array of systems, including the engine, cooling, fuel, lubrication, clutch, gearbox, torque multiplier, and various axle and brake systems. Detailed procedures for component disassembly, reassembly, and adjustment are included, alongside information on specialized tools and parts. This manual is an indispensable resource for owners, mechanics, and technicians seeking to ensure the optimal performance, longevity, and proper functioning of these agricultural workhorses.