First. The maintenance cycle of a 3 ton forklift is daily maintenance, that is, daily maintenance and inspection before starting the forklift. The first-level maintenance time is the cumulative operation of the engine for 150 hours. For internal combustion forklifts that work less than 150 hours a year, the first-level maintenance is carried out once a year. The secondary maintenance interval is 450 hours. For three forklifts whose working hours are less than 450 hours, the secondary maintenance will be carried out every three years.

Second. Routine maintenance
  1. Clean the dirt, soil and dirt on the forklift, the key parts are: forklift fork frame and mast slide, generator and starter, battery electrode fork column, water tank, air filter.
  2. Check the tightness of each part, focusing on: fork frame support, lifting chain tightening screws, wheel screws, wheel fixing pins, brakes, and steering gear screws.
  3. Check the reliability and flexibility of the steering gear.
4. Check for leakage. The key parts to be checked are pipe joints, diesel tanks, oil tanks, brake pumps, lifting cylinders, tilt cylinders, water tanks, water pumps, engine oil pans, torque converters, transmissions, drive axles, Main reducer, hydraulic steering gear, steering cylinder.
  5. Forklift tire pressure check: If it is insufficient, it should be added to the specified value to confirm that there is no air leakage. Check whether the tire contact surface and sides are damaged, and whether the rim is deformed.
  6. Check the brake fluid and water volume. Check whether the brake fluid is within the scale range, and check whether air is mixed in the brake pipeline. When adding brake fluid, prevent dust and water from mixing. When adding water to the water tank, use clean tap water. If antifreeze is used, add the same antifreeze. When the water temperature is higher than 70℃, do not open the water tank cover. When opening the cover, put a thin cloth on it and do not twist the water tank cover with gloves.
  7. Check the amount of oil, hydraulic oil and electrolyte of the forklift engine. Inspection method: first pull out the oil dipstick, clean the tip of the dipstick, insert it and then pull it out to check whether the oil level is between the two scale lines. The oil level in the working oil tank should be between the two scale lines. If there is too little oil, air will be mixed in the pipeline, and too much will overflow from the cover. The battery electrolyte should also be between the upper and lower scale lines. If it is insufficient, add distilled water to the top line.
   8. Brake pedal, inching pedal, clutch pedal, hand brake inspection method: Depress each pedal to check whether there is abnormal dullness or jamming. The force of the hand brake handle should be less than 300 N to confirm that the hand brake is safe and reliable.
   9. Check forklift belts, horns, lights, instruments, etc. During the inspection, if the belt tightness is found to be in compliance with the regulations, there is no adjustment margin, or it is damaged or cracked, it must be replaced; the horn, lights, and meters should all work normally.
  10. Put away the sediment from the oil filter.
Primary maintenance
   In accordance with the above "daily maintenance" items, and add the following tasks.
   1. Check the cylinder pressure or vacuum degree.
  2. Check and adjust the valve clearance.
   3. Check whether the thermostat is working properly.
  4. Check whether the multi-way reversing valve, lifting cylinder, tilt cylinder, steering cylinder and gear pump are working properly.
   5. Check whether the gear shifting of the transmission works normally.
   6. Check and adjust the gap between the brake pads of the hand and foot brakes and the brake drum.
  7. Change the oil in the oil pan, check whether the crankcase ventilation pipe is intact, and clean the oil filter and diesel filter element.
   8. Check whether the generator and starter motor are installed firmly, whether the wiring head is clean and firm, and whether the carbon brush and commutator are worn.
   9. Check the tightness of the fan belt.
  10. Check whether the wheel is installed firmly, whether the tire pressure meets the requirements, and remove the sundries embedded in the tread.
  11. Parts are disassembled due to maintenance work, and a forklift road test shall be carried out after reassembly.
  1) The braking performance under different degrees should be free from deviation or snaking. On steep slopes, after the hand brake is tightened, it can stop reliably.
   2), listen to the engine running under acceleration, deceleration, heavy load or no load, and whether there is any abnormal sound.
  3) After a period of road test, check the brakes, transmission, front axle housing, and gear pump for overheating.
  4) Whether the lifting speed of the fork frame is normal and whether there is tremor.
   12. Check whether the filter screen of the diesel tank oil inlet is blocked or damaged, and clean or replace the filter screen.
Secondary maintenance
   1. Clean the forklift body.
  2. Clean and replace the filter of the forklift. Such as forklift air, oil, gasoline filters, replacement of oil filters.
   3. Check the lubricating oil of various parts, clean the engine lubrication system, and replace the lubricating oil.
   4. Check and adjust the valve clearance.
   5. Clean and check the crankcase ventilation device.
  6. Measure the cylinder pressure, check the cylinder wear as the case may be, grind the valve and replace the piston ring to eliminate carbon deposits in the combustion chamber.
  7. Clean and check the filter.
   8. Check the piston and piston ring, check the running-in between the piston and the cylinder, and the fit of the piston pin with the seat hole and the bushing.
   9. Check the technical condition of crankshaft (connecting rod) journal and crankshaft (connecting rod) bearing. Check the axial clearance of the crankshaft and camshaft.
  10. Check the valve rocker arm, push rod, tappet and their coordination with the pilot hole.
  11. Check the axial and radial clearances of the distributor shaft.
  12. Clean the dirt inside the forklift generator, lubricate the bearings, and check the contact between the brush and the slip ring.
   13. Clean the outside of the battery, check the battery fixation and the height of the electrolyte level, and measure the electrolyte density and load voltage.
  14. Check the working conditions of various instruments, lighting and signals.
   15. Check and adjust the regulator voltage.
  16. Clean, inspect and lubricate the starter.
  17. Check and adjust the clutch and clutch friction plate.
  18. Check the tightening condition of the forklift's gearshift and check the technical condition of the gears.
  19. Check the technical condition of the forklift drive axle.
   20. Check and adjust the brake pedal, clutch pedal free stroke and parking brake operation stroke.
   21. Maintenance of fork wheel hub bearings, inspection tightness, cleaning, inspection, adjustment of wheel hub bearings, replacement of grease, inspection of the technical conditions of wheel hub oil seals and axle sleeves.
   22. Maintain the brake device and check the wear of the brake pipe, brake bottom plate and sheet. Check the brake main (wheel) cylinder cup, replenish the brake fluid, and check the braking efficiency.
  23. Maintain the steering device, check and adjust the lubrication steering gear, the connecting rod, and the installation status of the steering three-link plate. Check the installation status of the steering knuckle and the three steering plates. Check the installation status of the king pin. Clean, check and lubricate horizontal and straight rods. Check and adjust steering wheel positioning and steering angle.
  24. Check the tires, apply talcum powder, and rim rim paint.
   25. Check the dust-proof device of the whole car and lubricate the lubrication points of the whole car.
   26. Clean the fuel tank and check the working condition of the fuel tank cap.
   27. Check the hydraulic system, check the flexibility and stroke of the control lever of the distribution valve. Check the working condition of the oil pump and the wear of the spline. Check the pressure of the main relief valve of the distribution valve. Check the lifting cylinder and tilt cylinder for cracks, damage, deformation, and installation conditions.
  28. Check the oil leakage, damage and connection status of the joints of each pipeline.
  29. Check the working device, check the cracks, deformation, damage and bearing activity of the main frame. Check the lubrication, adjust the elongation, deformation and tightness of the lifting chain and sprocket, and the installation condition.
   30. Check the work equipment, such as the wear, deformation and installation conditions of forklifts and racks.
  31. Check the installation status and damage of the forklift driver's seat.
  32. Check the setting and damage of the overhead guard.
   33. Check the tightening of external bolts and nuts of the entire vehicle assembly and the installation and locking conditions.