一. Reasons for Heavy Steering in Trucks:
1：Insufficient hydraulic oil or air presence:
This is a common reason for heavy steering. Insufficient hydraulic oil or air in the system can affect the normal operation of the steering mechanism.
2：Faulty slide valve:
A large gap or improper closure of the slide valve can lead to heavy steering, requiring replacement of the steering screw and slide valve.
3：Damage to steering components:
Damage to the seals on the power steering piston or valve body can affect the steering mechanism's performance, necessitating replacement with new parts.
4：Faulty check valve:
Oil leakage from the check valve can result in heavy steering, requiring cleaning or replacement of the valve ball and seat.
5：Pump failure:
Low pump pressure or worn ball heads of the steering linkage, as well as poor lubrication of the steering knuckle pin, can lead to heavy steering, requiring adjustment or replacement of the pump.
二. Solutions:
1：Check hydraulic oil:
Inspect the filter element in the oil tank for damage or breakage. Clean if dirty or replace with a new filter element if damaged.
Check the oil level in the hydraulic oil tank. If it is too low, add hydraulic oil to reach the specified level. Also, purge any air from the oil.
2：Check steering components:
Check the lubrication of the steering knuckle pin and bushing. Clean or replace if corroded.
Check the operation of the slide valve. Replace the steering screw and slide valve as needed.
3：Check check valve and pump:
Inspect the sealing of the check valve ball and seat. Clean or replace the valve ball and seat as necessary.
Check the oil flow rate of the pump and the function of the safety adjustment valve. Readjust or replace the hydraulic pump.
4：Repair recommendations:
If the problem cannot be resolved independently, it is advisable to visit a professional 4S store for repairs and replace the steering mechanism with a new one.
