As an important piece of equipment for industrial handling, the maintenance of fuel-powered forklifts directly affects operational efficiency, service life, and operational safety. The following details the key points of maintenance for fuel-powered forklifts from the perspectives of daily, regular, and special circumstances:

I. Daily Maintenance (Before/After Daily Operations)

1. Appearance and Basic Inspections

• Vehicle Body Cleaning: Remove dust, oil stains, and material residues from the surface of the vehicle body, paying special attention to the engine compartment, radiator, and around the air filter to prevent blockages from debris that could affect heat dissipation or air intake.
• Tire Inspection:
  • Check the tire wear condition, ensuring that the tread depth meets the standard (generally not less than 1.6mm), and look for cracks, bulges, or embedded foreign objects (such as nails, stones).
  • Check the tire pressure and adjust it according to the values specified in the forklift manual (usually the front tire pressure is higher than the rear because the front tires bear the main load).
• Liquid Level Checks:
  • Fuel: Check the fuel tank level to ensure there is no leakage. Use a filter when refueling to prevent impurities from entering the fuel system.
  • Engine Oil: When the engine is cold, pull out the dipstick to check if the oil level is between "MIN" and "MAX". At the same time, check the color of the engine oil (normally light brown; if it turns black or emulsifies, it needs to be replaced).
  • Coolant: Check the liquid level in the expansion tank. If it is below the minimum mark, add the same type of coolant (do not add tap water to prevent scale formation), and check for leaks in the cooling system pipelines.
  • Brake Fluid: Check the liquid level in the brake fluid reservoir. Add the same specification of brake fluid if it is insufficient, and check for leaks in the brake pipelines.

2. Function Tests

• Brake System: After starting the forklift, gently step on the brake pedal to check if the braking is sensitive, if there are any abnormal noises, and if the brake pedal travel is normal (a soft pedal may indicate insufficient brake fluid or air in the system).
• Steering System: Turn the steering wheel to check if the steering is smooth, if there is any jamming or deviation, and if the level of steering power oil (if equipped) is normal.
• Lights and Instruments: Check if the headlights, turn signals, and brake lights are working properly, and if the dashboard indicator lights (such as oil pressure, water temperature, fuel level) are displaying normally.
• Lifting and Tilting Functions: Operate the fork to lift, tilt forward, and tilt backward. Check if the hydraulic system is functioning smoothly, if there is any oil leakage, and if the fork positioning is secure.

II. Regular Maintenance (Based on Usage Time/Mileage)

1. Weekly Maintenance

• Air Filter: Check if the filter element is clogged (it can be gently tapped or cleaned with compressed air blown in the reverse direction; if it is too dirty, it needs to be replaced) to avoid insufficient air intake to the engine, which could lead to reduced power.
• Hydraulic System: Check the oil level in the hydraulic oil tank, observe if the hydraulic oil has deteriorated (turned black or contains impurities), and replenish or ｒｅｐｌａｃｅ it if necessary. Check hydraulic pipelines and joints for leaks and tighten loose connections.
• Chains and Rollers: Apply grease to the fork lifting chains and mast rollers to reduce wear and ensure smooth lifting.

2. Monthly Maintenance

• Engine Maintenance:
  • Check the working condition of spark plugs (for gasoline engines) or fuel injectors (for diesel engines), clean carbon deposits, and ｒｅｐｌａｃｅ them if necessary.
  • Check the tightness of engine belts (such as fan belts and generator belts). A loose belt can cause poor heat dissipation or insufficient power generation, while an overly tight belt can easily wear out bearings.
• In-depth Brake System Inspection:
  • Check the wear condition of brake pads. ｒｅｐｌａｃｅ them in a timely manner when the thickness is insufficient (usually needs to be replaced when the remaining thickness is less than 3mm).
  • Bleed air from the brake system (if the pedal is soft) to ensure braking effectiveness.
• Battery (if equipped with auxiliary electrical equipment): Check the electrolyte level. Add distilled water if insufficient (do not add electrolyte). Clean oxide from the electrode terminals and apply petroleum jelly to prevent corrosion.

3. Quarterly Maintenance

• Transmission and Drive Axle: Check the oil level and oil quality of the transmission. Replenish or ｒｅｐｌａｃｅ the gear oil as needed (the gear oil replacement cycle for diesel forklifts is usually 1000-2000 hours). Check the drive axle for leaks and if the bearings are making abnormal noises.
• Cooling System: Clean dust and debris from the surface of the radiator to ensure good heat dissipation. Check if the water pump and thermostat are working normally (high water temperature may indicate a thermostat failure).
• Mast and Forks: Check the mast steel for deformation and cracks, and check the forks for bending and wear (forks need to be replaced if the wear at the top exceeds 10%). Ensure the fork positioning pins are secure.

4. Semi-annual/Annual Maintenance (or After Accumulated 1000-2000 Working Hours)

• Comprehensive Engine Maintenance: ｒｅｐｌａｃｅ engine oil and oil filters (use the oil type specified in the manual, such as 15W-40 commonly used for diesel engines). Thoroughly clean the engine oil passages and check cylinder pressure, valve clearance, etc.
• In-depth Hydraulic System Maintenance: ｒｅｐｌａｃｅ hydraulic oil and hydraulic oil filters, clean the hydraulic oil tank, and check the working status of hydraulic pumps and hydraulic motors to ensure normal pressure.
• Tightening of All Bolts: Check key parts such as frame, mast, and engine fixing bolts. Tighten loose bolts to prevent parts from falling off due to vibration.
• Safety Device Inspection: Such as seat belts, reversing radars, limiters, etc., to ensure they are fully functional and meet safety standards.

III. Maintenance Under Special Circumstances

• Long-term Inactivity (More Than 1 Month):
  • Drain all fuel (to avoid fuel deterioration), start the engine until it stalls naturally, and drain the engine oil and coolant.
  • Clean the vehicle body, apply anti-rust oil to exposed metal parts, lift the forks 10-15cm off the ground, inflate the tires to 1.2 times the specified pressure, and park it in a dry and well-ventilated place.
• After Operating in Harsh Environments (such as dusty, humid, or corrosive places):
  • Increase the inspection frequency of the air filter and hydraulic system, and promptly clean the filter elements and pipelines.
  • Thoroughly rinse the vehicle body after operation (avoid water entering the engine and electrical components), and strengthen anti-rust treatment for metal parts.

IV. Maintenance Precautions

• Use Original or Compatible Parts: Such as engine oil, filters, hydraulic oil, etc., to avoid equipment damage caused by inferior products.
• Standardize Tool Usage: Use special tools for maintenance and avoid rough disassembly (for example, do not forcefully tighten over-tight bolts; instead, apply a loosening agent).
• Record Maintenance Ledgers: Record in detail the time, content, and replaced parts of each maintenance to facilitate tracking of equipment status and plan the next maintenance in advance.
• Operation by Professionals: Complex maintenance (such as engine overhauls, transmission repairs) must be carried out by certified technicians to avoid safety accidents caused by improper operations.