How to check a second-hand tractor before buying?

Go through a proper checklist and take a trusted mechanic along. Engine: start it cold and watch the exhaust, heavy black or blue smoke and hard starting are warning signs; listen for knocking and check for oil leaks. Transmission and clutch: test every gear, the clutch should engage smoothly without slipping. Hydraulics: lift and lower an implement or the linkage a few times and see it holds without dropping. Steering and brakes: check for play and that brakes hold on a slope. PTO: engage it and confirm it runs without odd noise. Tyres: rear tyres are costly, check tread and sidewall cracks. Body and chassis: look for repaint hiding rust or accident repair. Hour meter and condition should roughly match. Papers: confirm the RC, that the engine and chassis numbers match the RC, finance is fully closed (no hypothecation pending), and there are no dues. Take a real test drive in a field, not just the yard. If the seller refuses inspection or a test, walk away. Get the final condition and papers verified independently before paying.