The hydraulic system on the loader uses liquid as the medium for transmitting power, so it is prone to leakage. After running for a long time, it is also prone to overheating, inability to work, damage to internal components and other failures. The occurrence of hydraulic transmission faults is sudden and hidden, and involves many components, which brings great difficulties to fault diagnosis and elimination. Therefore, when repairing the hydraulic system, it is necessary to understand its working principle and the basis for correctly analyzing the cause of the fault. Only in this way can the quality of repairs be guaranteed.
Steering hydraulic system failure causes and troubleshooting methods
Problem 1: Steering is heavy—The steering wheel is normal when turning slowly, but the steering wheel is heavy when turning fast.
Reasons and troubleshooting: There is air in the system and the oil level is too low. A large amount of air will be brought in when the oil is returned, so the oil should be replenished in time. You can use the steering to the extreme position and continue to turn the steering wheel to open the relief valve to discharge air. The control pressure of the priority valve is too low and the spring force decreases; check whether the spring is damaged or the permanent variable is too large and should be replaced in time. If the priority valve core is stuck in a certain position, the valve core should be removed, the valve body and other parts should be cleaned, and the valve core and valve body should be ground to ensure that the valve core can move freely in the valve body. The oil pump is damaged and the flow rate is insufficient. It should be repaired or replaced.
Problem 2: The steering is heavy—light when there is no load, heavy when there is a load
Reasons and troubleshooting: The steering relief valve setting pressure is too low. Check whether the spring is damaged or the permanent deformation is too large. The spring should be replaced in time. If the holding nut or pressure regulating bolt is loose, the pressure should be re-regulated and the nut should be tightened. The relief valve is not sealing, and the sealing surface of the valve core or valve seat is defective and should be repaired. If the pressure of the buffer valve in the valve block is too low, check whether the spring is damaged or the permanent deformation is too large. The spring should be replaced, or the sealing surface is not sealed and should be repaired. The oil pump is damaged and the flow rate is insufficient. The oil pump should be repaired or replaced.
Problem 3: The steering is heavy—the steering is heavy when the throttle is small, and the workload is normal after increasing the throttle.
Causes and troubleshooting: The oil pump is damaged and the flow rate is insufficient. The oil pump should be repaired or replaced. The matching clearance between the priority valve core and valve body is too large, and the valve core or assembly should be replaced.
Problem 4: The steering has no sense of end point—when the steering reaches the extreme position, turning the steering wheel is still very light.
Causes and troubleshooting: The steering gear valve body, valve core, valve sleeve, rotor, and stator are seriously damaged, and the clearance is too large. Worn parts or the steering gear should be replaced. The opening pressure of the relief valve or buffer valve is too low. The solution is the same as before.
Problem 5: Steering failure
Causes and troubleshooting: The steering wheel cannot return to center automatically, and the spring piece is broken and should be replaced. The pressure oscillation is obvious and even cannot rotate. The pull-out pin or linkage shaft has been damaged and should be replaced.
The oil pump is completely damaged or the rectangular key is cut off and should be repaired or replaced. The loader is lifted normally and the lifting speed is normal. When the load is lifted or forced to excavate, the load of the power machine increases. For example, the power machine emits black smoke and the cutting traction force decreases. When the load is lifted, the lifting speed does not decrease significantly during unloading. Valve cannot open. The valve core should be removed, the valve body and valve core should be cleaned, and the valve body and valve core should be ground to ensure that the valve core and valve body can move freely in the valve body.
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Post time: Aug-06-2024