Operation & Maintenance Manual
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LG958L/LG959 Wheel Loader
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2 HYDRAULIC SYSTEM
As shown in Figure 5-2, the hydraulic system includes the working equipment hydraulic system and
steering hydraulic system. The working equipment hydraulic system is composed of a work pump,
guiding valve, multi-way valve, lift arm cylinder, bucket cylinder, hydraulic pressure oil tank and pipe
attachments.
The hydraulic operating system employs a hydraulic guiding control system. The bucket unit includes
dumping, neutral and receiving bucket in three positions. The lift-arms unit controls four actions
including floating, lowering, neutral and lifting. The set pressure of the safety valve is 18
~
18.5MPa.
The overload pressure of the rocker cylinder’s large cavity is 20.5MPa while that of the small cavity
is 12MPa.
1. Work Pump 2. Hydraulic Oil Tank 3. Pressure Oil Tank 4. Pair Pump 5. Priority Valve
6. Steering 7. Combination of Valves 8. Steering Cylinder 9. Guiding Valve
10. Multi Passage Valve 11. Lift Arm Cylinder 12. Bucket Cylinder
Figure 5-2 Hydraulic System Diagram
The steering hydraulic system is the load sensing hydraulic system. This system is made up of a pair
pump, priority valve, steering, steering cylinder and the pipe attachments. In the process of turning,
this system supplies oil to the steering hydraulic system first, and then supply oil to working system
through radiator. The safety valve is on the priority valve. The adjusting pressure of the system is
16MPa.