| ProbleM | Causes | Troubleshooting |
| Oil leakage on the joint surface between the steering unit rear
cover, stator and valve body | rear cover stator bolt looseness (or uneven force), or O-rings
damaged | Evenly tighten the bolt, replace the seal |
| Oil leakage at steering shaft | Excessive wear or damage of the seal ring at the shaft of steering
unit | Replace new seal |
| feels light when turn the steering wheel slowly, feels heavy when
turn the steering wheel quickly | Insufficient oil supply from the oil pump to the steering unit | Check whether the oil pump is working properly (including liquid
level, oil pump efficiency, pipeline smoothness, etc.) |
| There is foam in the oil, irregular sound, the steering wheel turns
and the cylinder does not move | There is air in the steering system | Eliminating the air in the system, Check the suction pipe leaks or not, Or if the return nozzle is
below the liquid level |
| Heavy steering continues to occur | The oil in the tank is below the specified position | Add oil to prescribed height |
| Oil viscosity is too high | Use oil as required |
| Fast and slow steering wheels are both heavy, and there is no
pressure on steering | Check valve of the P and T fails | Check the ball. If the steel ball is missing, then insert the steel ball; If the ball gets stuck dirty, it should be cleaned; In both cases, it is necessary to check the effectiveness of the
sealing tape recovery. |
| No load or light load turns light, increase load turns to heavy | Relief valve is of system's pressure lower than required value | Adjust the pressure of the relief valve to the specified value (but
not more than 16 MPa) |
| Relief valve stucked by dirt, Or spring failure,Or seal is damaged | Clean the relief valve (check the effectiveness of the sealing
tape), or replace the spring or sealing ring |
| Steering wheel cannot be automatically centered | Spring broken or deformation | Replace with new spring |
| Steering wheel rotates or swings left and right automatically | Rotor and the linkage shaft are in the wrong position | Stop immediately! Align the rotor and linkage shaft |
| Can not reach an end position | Low pressure on relief valve | Properly increase the pressure of the safety valve (it is best to
adjust with a pressure gauge) |
| After turning to the end, the steering wheel can still be easily
turned | Low pressure on shock valves | Properly increase shock valves pressure (it is best to adjust with
a pressure gauge) |
| when machine is off, turn the wheel, cylinder not move | radial clearance or axial clearance is too large between radial and
stator | Replace rotor and stator |
| Low viscosity of oil | Change oil |
| Slow cylinder action | shock valves failure (ball caught by dirty, or spring failure, or
seal damage) | Clean shock valves, replace spring or seal |
| Pressure of Steering system not able to be adjusted | Spring broken | Replace the spring |
| Safety valve sealing quality is not high | Replacement parts |
| Spool blocked | Take out, check, and refurbish |
| Poor spool action | Check whether the spool is blocked |
| Spring bent or too soft | Replace the spring |
| Oil is not clean and the spool hole is blocked | Replace clean oil and clear spool holes |
