# Comprehensive Guide to Tractor Repair and Maintenance

I. Daily Maintenance Checks 1. Pre-Start Daily Inspection ■ Engine Oil Check - With the engine off, check the dipstick to ensure the oil level is between "MIN" and "MAX" - Oil color should be clear amber; if it appears black or contains metal particles, replace it immediately ■ Cooling System - Check the coolant level in the radiator (should be 3-5 cm below the filler neck) - Inspect for signs of leakage (pay special attention to hose connections and the water pump) ■ Fuel System - Drain water accumulated at the bottom of the fuel filter (diesel models) - Check the fuel lines for air (the primer pump should feel firm with no sponginess) ■ Tires / Tracks - Tire pressure: 2.0-2.5 bar for dry field operations, 1.2-1.8 bar for paddy field operations - Track tension: Sag at the center section should be 20-30 mm 2. Post-Operation Inspection - Clean the radiator grille (especially watch for buildup of straw and weeds) - Check tightness of bolts at various points (key areas: wheel hubs, drive shafts, suspension mounting points) - Empty dust from the air filter dust cup (dry-type filters) II. Scheduled Maintenance Plan 1. Every 50 Hours of Operation - Replace the engine oil filter (for the first service, it is recommended to advance this to 30 hours) - Grease all grease fittings (including steering tie rods, suspension pivots, etc.) - Check battery electrolyte level (for non-maintenance-free batteries) 2. Every 250 Hours of Operation ■ Engine Oil Change - Drain old oil while the engine is warm - Recommended oil: diesel engine oil of CF-4 grade or higher - Typical capacity: 1.5-2 L for single-cylinder engines, 6-8 L for four-cylinder engines ■ Fuel Filter Replacement - Bleed air from the fuel system first - Fill the new filter with clean diesel before installation 3. Every 500 Hours of Operation ■ Transmission Oil Change - Use GL-5 grade 80W-90 gear oil - Note the difference between oil for wet-clutch transmissions and standard transmissions ■ Hydraulic System Maintenance - Replace the hydraulic oil filter element - Check hydraulic oil cleanliness (replace if contamination exceeds NAS Class 9) ■ Valve Clearance Adjustment - Perform with the engine cold - Typical values: intake valve 0.2-0.25 mm, exhaust valve 0.25-0.3 mm III. Common Fault Diagnosis and Troubleshooting 1. Engine Faults ■ Hard Starting - Inspection sequence: electrical system → fuel system → compression - In winter, check the glow plugs (resistance should be 0.6-1.0 Ω) ■ Insufficient Power - Check the turbocharger (if equipped) for oil leaks - Test injector nozzle atomization (standard injection pressure: 180-220 bar) 2. Transmission System Faults ■ Clutch Slipping - Check pedal free travel (standard: 15-20 mm) - Measure friction disc thickness (replace if below 2 mm) ■ Abnormal Transmission Noise - Distinguish between bearing damage (continuous hum) and gear damage (periodic knocking) 3. Hydraulic System Faults ■ Weak Lifting - Test the relief valve opening pressure (typically 12-15 MPa) - Check hydraulic pump volumetric efficiency (overhaul required if below 80%) ■ Excessive Oil Temperature - Check whether the oil cooler is clogged - Verify the correct hydraulic oil viscosity (SAE 46 recommended for summer, SAE 32 for winter) IV. Seasonal Maintenance Essentials 1. Winter Maintenance - Switch to low-freezing-point diesel (choose -10# or -20# based on ambient temperature) - Insulate the battery (or remove and store it indoors) - Add antifreeze to the cooling system (ethylene glycol type with freezing point ≤ -25°C) 2. Summer Maintenance - Increase cooling system cleaning frequency (clean the exterior of the radiator weekly) - Reduce tire pressure by 0.2-0.3 bar to prevent blowouts - Inspect the insulation of the electrical system (to prevent spontaneous combustion) V. Long-Term Storage Maintenance ■ Protective Treatment - Fill the fuel tank completely and add a fuel stabilizer - Apply rust-preventive grease to exposed metal surfaces ■ System Protection - Start and run the engine for 15 minutes each month (or turn the crankshaft several revolutions) - Retract hydraulic cylinder piston rods to the shortest position ■ Storage Environment - Choose a dry, well-ventilated location - Cover with a dedicated tarp (avoid direct sunlight exposure) VI. Safety Precautions for Repairs ■ Operational Safety - Display a "Maintenance in Progress" warning sign during repairs - Always use safety stands when lifting equipment (never rely solely on hydraulic support) ■ Use of Professional Tools - Torque wrench (important bolts must be tightened to the torque specified in the manual) - Use special guide tools when disassembling or assembling hydraulic cylinders ■ Environmental Requirements - Collect waste oil separately for disposal (never drain directly into the environment) - Dispose of old filters as hazardous waste VII. Recommended Repair Tool List Tool Category | Essential Tools | Specialized Tools Basic Tools | Socket wrench set, torque wrench, screwdriver set | Valve adjustment shim kit Specialized Tools | Piston ring compressor, bearing puller | Hydraulic system tester Diagnostic Equipment | Digital multimeter, cylinder compression gauge | Injector nozzle test bench VIII. Technical Documentation Access Channels - Original manufacturer's service manual (including wiring diagrams and hydraulic schematics) - Manufacturer after-sales hotline (most brands offer remote guidance) - Professional agricultural machinery repair forums (case sharing and experience exchange) Note: For complex faults, it is recommended to contact an authorized service center. Disassembling precision components such as the ECU by yourself may void the warranty. Keeping complete maintenance records is very important for resale transactions and value assessment.