The International Harvester B-250 and B-275 tractors, produced in the late 1950s to early 1960s, represent robust and reliable light to medium-duty utility vehicles. These tractors, often powered by diesel engines with displacements around 2.5 to 2.7 liters and producing approximately 35 to 40 horsepower, were designed for a variety of agricultural tasks. Known for their sturdy construction and straightforward mechanical operation, they have earned a reputation for longevity and dependable performance in demanding environments. Their enduring appeal lies in their functional design and the essential role they played in farming operations of their era. This comprehensive workshop service repair manual provides detailed information for the International Harvester B-250/B-275 tractor. It covers a wide array of systems, including the engine, cooling system, fuel system, powertrain, clutch, brakes, hydraulic system, and electrical system, among others. The manual offers step-by-step instructions for complete disassembly and reassembly, troubleshooting, diagnostics, and maintenance procedures. With hundreds of photos, illustrations, and detailed diagrams, it serves as an invaluable resource for both do-it-yourself owners and experienced mechanics seeking to maintain, repair, and understand their tractor.