There is no leakage in the balance valve, and there is no problem with the reversing valve, why the

I have also encountered this situation, because there is a problem with the internal seal of the cylinder, to exaggerate it, it is a rod cavity and a rodless cavity are connected. The inspection method is: the oil cylinder rises (or falls) in place, and then the upper (or lower) oil pipe is removed, wait until the oil flows out, and then the system is pressurized, if there is still oil flowing out of the oil port, you can judge that there is a problem with the internal seal.

The above is for reference.

1. The balance valve is not adjusted properly.

2. Leakage of oil cylinder.

3. The balance valve is not installed on the valve block next to the cylinder, or there is a long hose connection between the balance valve and the oil cylinder.

There are many reasons, depending on the schematic, and there may be other reasons.

1. Leakage of cylinder seals.

2. The solenoid valve spool seal is leaking.

The control port of the balancing valve can also sometimes leak, causing the cylinder to move.

Troubleshooting method of hydraulic power steering: check whether the pipelines of the entire hydraulic steering system are blocked. The failure of the hydraulic line is a relatively hidden and difficult fault of the steering system.

If the pipeline is completely blocked, the fault is relatively easy to deal with. Sometimes the line is partially blocked, and the pressure generated by the booster pump is insufficient, resulting in heavy direction. This failure is mainly caused by debris in the oil and the aging and expansion of the hose, so the hydraulic line must be replaced regularly.

Prevention should be the first and deal with it in a timely manner. Diagnosis and elimination of faults of directional power pump and directional machine. If the mechanical part and the hydraulic pipeline are not faulty, you can find a first-class steering power pump to install on the car for testing.

After starting the car, turn to the left and right, if the steering is normal, it means that the original booster pump is faulty. If the direction is still heavy after replacing the booster pump, you can remove the directional booster and go to the calibration table to correct it and check its fault. For units that do not have a calibration bench, they can be replaced with a new directional booster or a fault-free directional booster to be tested on the vehicle to determine whether the original directional booster is faulty.

The main reason for the difficulty in returning the steering wheel is that the control valve of the hydraulic power assist system is not adjusted correctly, and the hydraulic valve sticks or has dirt stuck. Check them one by one. It may be that the hydraulic valve is not properly assembled, there is air on one side of the booster cylinder, and there is oil leakage or premature unloading on one side of the pressure limiting valve

The method of elimination is: bearing tightness, excretion of air from the cylinder, and if necessary, check the hydraulic valve and piston.