4-5 Ton Internal Combustion Forklift

1.Engine Issues

①Problem: Difficulty Starting the Engine

Possible Causes:

Insufficient fuel or clogged fuel lines

Low battery charge/starter motor failure

Clogged air filter

No preheating in cold conditions (diesel engines)

Solutions:

Check fuel level and filter, clean fuel lines;

Test battery voltage, recharge or replace;

Clean or replace the air filter;

Use the preheating function for diesel engines in cold weather.

②Problem: Black Smoke from the Engine

Cause: Incomplete combustion (excess fuel or insufficient air intake).

Solution:

Check if the air filter is clogged;

Adjust the fuel injector or high-pressure pump;

Avoid overloading.

2.Hydraulic System Issues

①Problem: Slow or Weak Lifting

Possible Causes:

Low hydraulic oil level or degraded oil quality;

Hydraulic pump wear or oil leakage;

Improper adjustment of the control valve.

Solution:

Refill or replace hydraulic oil (use manufacturer-specified grade);

Check pump and pipeline seals;

Contact a technician to adjust the pressure valve.

②Problem: Fork Drifting Down Automatically

Cause: Worn hydraulic cylinder seals or internal valve leakage.

Solution: Replace seals or repair the control valve.

3.Transmission Issues

Problem: Gearbox Noise or Difficulty Shifting

Possible Causes:

Low or degraded gear oil;

Worn clutch plates (mechanical transmission);

Loose shifting linkage.

Solution:

Check oil level and replace gear oil;

Adjust or replace clutch friction plates;

Tighten linkage bolts.

4.Steering System Issues

Problem: Heavy Steering

Causes:

Low hydraulic steering fluid;

Faulty steering gear or power steering pump;

Low tire pressure.

Solution:

Refill or replace hydraulic fluid;

Check power steering pump pressure;

Maintain proper tire pressure.

5.Routine Maintenance Issues

①Problem: When to Replace the Three Filters (Air/Oil/Fuel)?

Recommendations:

Air filter: Every 200-300 hours (depending on working conditions);

Oil filter: With every oil change (~500 hours);

Fuel filter: Every 1,000 hours or as per manufacturer guidelines.

②Problem: Abnormal Tire Wear

Causes: Incorrect tire pressure, overloading, or frequent hard braking.

Solution: Regularly check tire pressure and operate correctly.

6.Safety Operation Notes

Problem: Sudden Engine Shutdown During Operation

Emergency Steps:

Brake immediately and lower the forks;

Check fuel and electrical systems;

If unresolved, contact maintenance personnel.

Problem: Exhaust Odor (LPG/Diesel)

Possible Causes: Incomplete combustion or gas leakage (LPG).

Action: Stop the engine, inspect fuel lines, and ensure proper ventilation.

7.Other Common Issues

Battery Drain:

Charge regularly and avoid prolonged inactivity.

Dashboard Warning Lights:

Refer to the manual for error codes (e.g., high coolant temperature, low oil pressure).