Maintenance of Safety Auxiliary Systems for Electric Forklifts in Winter

Maintenance of safety auxiliary systems for electric forklifts in winter shall focus on equipment reliability and protection effectiveness under low-temperature conditions. In line with the core requirements of anti-freezing, moisture-proofing and fault prevention, the following hierarchical maintenance key points are specified, including quantitative standards and responsible entities, which can be directly applied to standardized operations:

Key Maintenance Points for Safety Auxiliary Systems of Electric Forklifts in Winter

I. Brake Safety Subsystem (Core Safety Item, Daily Inspection Mandatory)

Affected by low temperatures, the brake system is prone to problems such as thickened brake fluid, increased brake clearance and pipeline air leakage. The maintenance key points are as follows:

1. 1.Special Maintenance of Brake Fluid
   • Medium Selection: Winter-specific brake fluid of DOT4 or DOT5.1 grade must be used, with a required pour point ≤ -40℃ and low-temperature fluidity ≥ 1200mm²/s (at -20℃). Mixing different types or expired brake fluid is strictly prohibited.
   • Liquid Level and Purity Inspection: Check the liquid level in the reservoir before daily operation to ensure it remains between the MAX and MIN scale lines. If the liquid level drops rapidly, inspect the pipeline for leakage. Test the water content of the brake fluid monthly; ｒｅｐｌａｃｅ the fluid immediately if the water content exceeds 3% to prevent low-temperature freezing and pipeline blockage.
   • Bleeding Operation: After replacing the brake fluid or repairing pipelines, thoroughly bleed the brake system. Start the forklift and repeatedly press the brake pedal 10-15 times until the pedal feels firm with no excessive travel, avoiding brake failure caused by vapor lock.
2. 2.Maintenance of Brake Actuator Components
   • Brake Pads and Discs: Inspect the thickness of brake pads; mandatory replacement is required if the remaining thickness is less than 3mm. Grind and repair the brake disc if the surface flatness error exceeds 0.1mm to prevent jitter during braking. Clean snow, ice and sediment between brake pads and discs every half month in winter to avoid jamming.
   • Parking Brake System: Adjust the tension of the parking brake cable to ensure the forklift can reliably park in an unloaded state on a 15° slope, with no rust or breakage on the cable. Lubricate the cable guide sleeve monthly with low-temperature grease (temperature resistance: -30℃).
   • Pipelines and Joints: Check brake hoses for aging and cracking. Tighten metal pipeline joints to the torque specified by the manufacturer (usually 8-12N·m). Due to metal contraction in low winter temperatures which may cause loosening, re-tighten the joints once a week.
3. 3.Lighting and Warning Subsystem (Environment Adaptation Item, Full Inspection Weekly)With shorter daylight hours and frequent rain, snow and fog in winter, the reliability of lighting and warning devices directly affects operation safety. The maintenance key points are as follows:
   • Lighting System Maintenance
     • Function Inspection: Turn on headlights, turn signals, brake lights, reverse lights and marker lights daily to ensure brightness meets the standard (headlight illuminance ≥ 200lx at 10m). ｒｅｐｌａｃｅ damaged bulbs with ones of the same specification and model immediately.
     • Cleaning and Protection: Remove snow, ice and dust from the lamp cover surface to prevent reduced light transmittance. Check the lamp cover sealing rubber strips; ｒｅｐｌａｃｅ aging or damaged strips to avoid moisture ingress and internal fogging.
     • Wiring Fastening: Inspect lighting harness connectors; pull them out, clean oxide layers, apply conductive anti-rust agent, reinsert and lock the buckles to prevent poor contact caused by low-temperature vibration.
   • Warning Device Maintenance
     • Reverse Buzzer and Warning Light: Test the volume of the reverse buzzer to ensure it reaches ≥ 90dB at a distance of 5m; ｒｅｐｌａｃｅ the buzzer if the volume is insufficient. Maintain the warning light flashing frequency at 60-90 times per minute; inspect the controller or bulb if flashing is abnormal.
     • Safety Warning Signs: Check warning signs on the forklift body such as "Caution: Slippery Surface" and "Load Limit". Reattach or ｒｅｐｌａｃｅ signs promptly if they are fallen off or blurred to ensure clear identification by operators and surrounding personnel.

4. 4.Operation and Protection Subsystem (Man-Machine Safety Item, In-Depth Inspection Monthly)

5. Low temperatures can cause jamming of operating components and reduced toughness of protective devices. Focus on the following maintenance content:

   • Operation Mechanism Maintenance
     • Control Levers and Pedals: Apply graphite low-temperature grease to the hinge points of the steering wheel, lifting/tilting control levers and brake pedal. Ensure the operating force is ≤ 50N (for control levers) and the pedal stroke complies with the manufacturer's specifications (usually 100-150mm), with no jamming or poor return.
     • Safety Limit Devices: Inspect the sensors of the fork lifting limit and mast tilting limit to ensure sensitive triggering. Blow off snow, ice and dust on the sensor surface with compressed air every half month in winter to prevent signal failure.
   • Protection Device Maintenance
     • Seat Belt System: Check seat belt webbing for aging and tearing; ensure the buckle locks reliably and the belt retracts smoothly. Tighten the seat belt fixing seat bolts to the specified torque (15-20N·m) and check for cracks at welding points. ｒｅｐｌａｃｅ the entire assembly immediately if any problem is found.
     • Overhead Guard and Load Backrest: Conduct visual inspection and magnetic particle testing on the overhead guard, focusing on welded parts. Stop using and ｒｅｐｌａｃｅ the guard immediately if cracks are detected; welding repair is prohibited. Ensure the load backrest is firmly installed, with a clearance ≤ 5mm from the fork carriage to prevent cargo slipping.
     • Cab Protection (if equipped): Check door and window sealing rubber strips; ｒｅｐｌａｃｅ aging or damaged parts to prevent cold wind, rain and snow from entering. Ensure the air outlet temperature of the heating system reaches ≥ 40℃ (10 minutes after startup) and the air duct is unobstructed, improving operator comfort and avoiding misoperation caused by low-temperature fatigue.

II. Maintenance Responsibilities and Execution Frequency