# Comprehensive Guide to the Regular Maintenance Process for Rough Terrain Forklifts (Professional Edition)

I. Daily Pre-Operation Inspection (10-Minute Quick Check) Oil and Fluid Systems Engine oil dipstick check (10 minutes after shutdown); hydraulic oil level observation (at center of sight glass when oil temperature is 40°C); coolant expansion tank level (not below MIN line). Critical Components Tire pressure check (refer to door frame calibration value ±5%); fork crack inspection (focus on root weld area); chain tension (sag < 10mm). Safety Device Testing Parking brake performance (should hold on 20% grade); warning light/reverse buzzer function verification; emergency descent device manual test. II. Weekly Deep Maintenance (Recommended during weekend downtime) Transmission System Differential oil level check (warm engine condition); driveshaft cross joint greasing (use lithium-based grease); wheel hub reducer leak inspection. Hydraulic System Filter differential pressure indicator check (replace immediately if red indicator pops out); multi-way valve fastening bolt torque re-check (refer to service manual); cylinder piston rod surface cleaning (remove corrosive deposits). Electrical System Battery terminal anti-oxidation treatment (apply petroleum jelly); wiring harness connector waterproofing check (wiggle test); instrument panel fault code reading and recording. III. Monthly Professional Maintenance (Requires equipment administrator participation) Power System Diesel fuel filter replacement (for models with oil-water separator); turbocharger axial clearance inspection (< 0.8mm); EGR valve carbon deposit cleaning (for China IV and above models). Structural Component Inspection Frame weld magnetic particle inspection (focus on stress concentration areas); steering axle kingpin clearance measurement (adjust if > 2mm); cab ROPS bracket bolt re-tightening. Performance Testing Hydraulic system pressure calibration (main pump + steering system); braking distance test (empty load 20km/h ≤ 6m); PTO output speed calibration (within ±3% tolerance). IV. Quarterly Major Maintenance (Recommended with manufacturer service personnel participation) Oil and Fluid Replacement Full hydraulic oil replacement (clean tank simultaneously); transfer case gear oil renewal (API GL-5 grade); coolant freezing point test (< -25°C). Precision Components Fuel injector atomization test (professional equipment); pilot valve sensitivity adjustment (response time < 0.5s); angle sensor calibration (mast tilt system). Wear Part Replacement Air filter assembly replacement (shorten cycle by 50% in desert environments); brake friction pad thickness inspection (replace if < 5mm); tire rotation (cross-pattern method). V. Annual Comprehensive Overhaul (Requires professional equipment support) Disassembly and Inspection Engine cylinder compression test (deviation < 10%); transmission clutch disc 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 undercoating re-spray (polyurea material); wiring harness conduit replacement (oil-resistant type); full vehicle grounding resistance test (< 0.1Ω). VI. Additional Maintenance for Special Operating Conditions High-Dust Environments Air filter daily blow-down (0.5MPa compressed air); radiator weekly flushing (reverse airflow method); cab seal strip monthly replacement. Water-Fording Operations Wheel hub bearing weekly greasing (expel moisture); differential breather valve modification (raised type); full vehicle wiring harness waterproofing test (500V megohmmeter). Low-Temperature Environments Fuel heater daily inspection; hydraulic oil changed to low-pour-point grade (HV46); tires filled with nitrogen (anti-icing). Maintenance Record Management (ISO Standard Template) Item Standard Value Actual 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 so that the complete service history can be viewed by scanning with a mobile phone. For equipment exceeding 2,000 operating hours, oil spectrum analysis technology is recommended for predictive maintenance. (Note: Specific intervals can be adjusted based on actual operating intensity; for heavy-duty applications, it is recommended to shorten all intervals by 30%.)