# Complete Guide to Periodic Maintenance of Rough Terrain Forklifts (Professional Edition)

I. Daily Pre-Operation Inspection (10-Minute Quick Check) Fluid Systems Engine oil dipstick check (after 10 minutes of shutdown); hydraulic oil level observation (at the center line of the sight glass when oil temperature is 40°C); coolant expansion tank level (not below the MIN line). Key Components Tire pressure check (refer to door frame specification ±5%); fork crack inspection (focus on root weld areas); chain tension (sag <10mm). Safety Device Testing Parking brake effectiveness (should hold on a 20% gradient); warning lights/reversing buzzer function verification; manual test of emergency lowering device. II. Weekly Deep Maintenance (Recommended During Weekend Downtime) Drivetrain Differential oil level check (warm engine condition); driveshaft universal joint greasing (use lithium-based grease); wheel hub reducer leak inspection. Hydraulic System Filter differential pressure indicator check (replace immediately if red pops out); multi-way valve fastening bolt torque recheck (refer to maintenance manual); cylinder piston rod surface cleaning (remove corrosion). Electrical System Battery terminal anti-oxidation treatment (apply petroleum jelly); wiring harness connector waterproofing check (wiggle test); dashboard fault code reading and recording. III. Monthly Professional Maintenance (Requires Equipment Manager Participation) Power System Diesel filter replacement (models with oil-water separator); turbocharger axial clearance detection (<0.8mm); EGR valve carbon deposit cleaning (China IV and above models). Structural Component Inspection Frame weld magnetic particle inspection (focus on stress concentration areas); steering axle kingpin clearance measurement (>2mm requires adjustment); cab ROPS bracket bolt re-tightening. Performance Testing Hydraulic system pressure calibration (main pump + steering system); braking distance test (unloaded at 20km/h ≤6m); PTO output speed calibration (within ±3% error). IV. Quarterly Major Maintenance (Recommended with Manufacturer Service Personnel Participation) Fluid Replacement Full hydraulic oil replacement (simultaneously clean oil tank); transfer case gear oil renewal (API GL-5 grade); coolant freezing point test (<-25°C). Precision Components Injector atomization test (professional equipment); pilot valve sensitivity adjustment (response time <0.5s); angle sensor calibration (mast tilt system). Wear Parts Replacement Air filter assembly replacement (shorten cycle by 50% in desert areas); brake friction pad thickness measurement (replace if <5mm); tire rotation (cross-rotation method). V. Annual Comprehensive Overhaul (Requires Professional Equipment Support) Disassembly Inspection Engine cylinder compression test (deviation <10%); transmission clutch plate thickness measurement; hydraulic pump volumetric efficiency test (<80% requires major overhaul). System Upgrades Electronic control system software flashing (latest version); safety valve opening pressure reset; lighting system LED conversion. Anti-Corrosion Treatment Chassis armor re-coating (polyurea material); wiring harness conduit replacement (oil-resistant type); full vehicle grounding resistance test (<0.1Ω). VI. Additional Maintenance for Special Working Conditions High Dust Environment Air filter daily blow-down (0.5MPa compressed air); radiator weekly flushing (reverse airflow method); cab weatherstrip monthly replacement. Water Wading Operations Wheel hub bearings weekly greasing (expel moisture); differential breather valve modification (raised type); full vehicle wiring harness waterproofing test (500V megohmmeter). Low Temperature Environment Fuel heater daily inspection; hydraulic oil change to low pour point type (HV46); tire nitrogen inflation (anti-icing). Maintenance Record Management (ISO Standard Template) Item Standard Value Measured Value Performed By Next Maintenance Date Engine Oil SAE 15W-40 Normal Zhang San 2023-11-15 Hydraulic Filter <0.3MPa 0.25MPa Li Si 2023-10-30 Professional Recommendation: Establish a QR code electronic maintenance archive; scan with a mobile phone to view complete service history. For equipment with over 2,000 hours, predictive maintenance using oil spectral analysis technology is recommended. (Note: Specific intervals can be adjusted based on actual operating intensity. For heavy-duty conditions, it is recommended to shorten all intervals by 30%.)