Tractor maintenance includes the routine inspection, servicing, and replacement of fluids, filters, belts, and wear items that keep the tractor operating reliably. An hour meter is the primary reference for maintenance intervals, with engine oil and filter typically changed every 100 to 200 hours, hydraulic fluid every 400 to 600 hours, and coolant every 1000 to 2000 hours. Daily pre-start checks include coolant level, engine oil level, hydraulic fluid level, tire pressure, and visual inspection for leaks or damage. [[Tractor Implements]] require the tractor to be in proper working condition for safe attachment operation.
Engine oil is the most critical fluid. Diesel tractor engines use API CJ-4 or CK-4 rated oil, typically 15W-40 viscosity. The oil and filter should be changed according to the manufacturer's schedule, usually every 100 to 200 hours for compact tractors. Hydraulic fluid and transmission fluid, often combined in a single reservoir on compact tractors, should be checked with the dipstick at operating temperature. The hydraulic filter should be replaced every 400 to 600 hours. Coolant should contain a 50-50 mixture of antifreeze and distilled water with supplemental coolant additives for diesel engine protection.
Air filters are inspected every 50 hours and replaced when dirty. Operating in dusty conditions, common in haying and tillage, requires more frequent air filter attention. The fuel filter should be replaced annually or every 400 hours. Water separators on diesel tractors should be drained at every oil change. Fan belts and alternator belts are inspected for cracking and tensioned to deflect 10 to 15 millimeters (3/8 to 5/8 inch) under moderate thumb pressure.
Tractor batteries are subjected to vibration that can cause internal plate damage. Battery terminals should be cleaned annually, and the battery should be secured in its mount. Glow plugs on diesel tractors should be tested if starting is difficult in cold weather. The alternator output should be checked, typically 13.5 to 14.5 volts. [[Small Engine Repair]] covers ignition and charging system troubleshooting for smaller engines.
Tire pressure should be maintained at the manufacturer's recommended level, typically 15 to 25 psi for rear agricultural tires and 30 to 45 psi for front tires. Liquid tire ballast, typically calcium chloride solution or Rim Guard, adds 100 to 200 kilograms (200 to 400 pounds) per tire for additional traction. Front axle pivot points and steering linkage should be greased every 50 hours.