Maintaining the hydraulic system of small four-wheel tractors focuses on "regular oil management, component inspection, and pollution prevention"-follow this practical, step-by-step guide to ensure stable operation and extend service life:
1. Daily Routine Maintenance (5–10 Minutes Before/After Operation)
1.1 Pre-Operation Quick Check
Oil Level & Quality: Park on flat ground, shut down the engine, and confirm oil level is between "MAX" and "MIN" scales. Visually check oil clarity (no turbidity/foam).
Leakage Inspection: Rapidly scan pipe joints, cylinder ends, and pump/valve bodies for oil stains or dripping; tighten loose joints immediately.
Component Check: Ensure the radiator is free of dust/straw clogging, and the hydraulic control lever moves flexibly.
1.2 Post-Operation Tidying
Cleaning: Wipe the oil tank cap, radiator surface, and hydraulic components with a clean rag to prevent dust accumulation.
Pressure Relief: Return the hydraulic control valve to neutral to release residual system pressure.
Drainage: Every 50 working hours, open the oil tank bottom drain valve to discharge condensed water and sediment (critical in humid environments).
2. Periodic Maintenance (By Working Hours, Core to Extend Life)
2.1 Every 100 Working Hours
Lubricate the hydraulic cylinder piston rod with lithium-based grease to prevent rust and reduce friction.
Clean the oil tank cap's air filter (avoids dust entering the system).
Inspect rubber oil hoses for cracks/aging; replace if damaged.
2.2 Every 200 Working Hours
Clean the detachable suction filter (if equipped) with diesel oil to avoid clogging and insufficient oil intake.
Check the cooling fan (electric/belt-driven) for normal operation; tighten loose belts or repair faulty motors.
2.3 Every 500–800 Working Hours (Key Maintenance)
Full Oil Change: Drain old oil completely, clean the tank interior with diesel oil, and refill with specified hydraulic oil (e.g., 46# anti-wear oil meeting GB/T 11118.1).
Filter Replacement: Replace the oil filter element synchronously with oil changes (use model-matching filters).
Seal Inspection: Check pump shaft seals, valve core seals, and cylinder piston seals for wear/leakage; replace aging parts with original components.
2.4 Every 1 Year (Annual Overhaul)
Calibrate hydraulic pump output pressure and relief valve setting pressure with a pressure gauge (align with manufacturer's rated value).
Disassemble and clean the control valve/one-way valve; remove impurities and apply lubricant to ensure flexible valve core movement.
Replace all rubber oil hoses (even if no obvious damage) to avoid sudden bursts due to aging.
3. Special Scenario Maintenance (Adapt to Environment/Load)
Cold Regions: Use 32# anti-wear hydraulic oil in winter; preheat the system at idle for 5–10 minutes before operation to ensure oil fluidity.
High-Temperature/Heavy-Load: Shorten oil change cycles to 300–500 working hours; clean the radiator every 150 working hours to enhance heat dissipation.
Dusty Environments: Replace the air filter every 3 months; add a pre-filter to the oil intake to reduce dust contamination.
4. Critical Maintenance Taboos
Do not mix different types/grades of hydraulic oil (causes chemical reactions and seal damage).
Never operate the system when oil temperature exceeds 85°C (stop to cool down immediately to avoid oil oxidation).
Avoid overloading (exceeding rated lifting load) or sudden starts/stops of the hydraulic system (reduces component wear).
Use only original or model-matching parts (filters, seals, hoses) to prevent secondary faults.
