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Diagnosis Method of Hydraulic System Failure of Excavator

The hydraulic system is one of the most important systems in machinery and one of the most prone to failures. Landheroparts summarizes three methods for judging hydraulic system failures for you.、

1. Visual Inspection

For some relatively simple faults, parts can be inspected by means of eye, hand mold, ear listening and smell. For example, visual inspection can find faults such as cracks, oil leakage, loosening and deformation, so that they can be detected in time. Repair or replace accessories; hold the oil pipe (especially the rubber hose) by hand, when there is pressure oil flowing through, there will be a vibration feeling, but there is no such phenomenon when there is no oil flowing or the pressure is too low.

In addition, hand touch can also be used to judge whether the lubrication of hydraulic components with mechanical transmission parts is good. Feel the temperature change of the component shell with your hand. If the component shell is overheated, it means that the lubrication is poor; listening to the mechanical components can be judged. The fault point and degree of damage caused by the damage, such as hydraulic pump suction, overflow valve opening, component issue, etc., will make abnormal sounds such as water impact sound or “water hammer”; some parts will be due to overheating, poor lubrication and cavitation. If there is a peculiar smell due to other reasons, the fault point can be judged by smelling it.

Diagnosis Method of Hydraulic System Failure of Excavator

2. Swap Diagnosis

When there is a lack of diagnostic instruments at the maintenance site or the inspected components are too precise to be disassembled, this method should be used to first remove the components suspected to be faulty and replace them with new ones or other components that work normally and are of the same type for testing. The diagnosis can be made if the fault can be eliminated.

Using the swap diagnosis method to check the fault, although it may be troublesome to operate due to factors such as structure, on-site component storage or inconvenient disassembly, etc., for small and easy-to-use components such as balance valves, relief valves, and one-way valves. It is more convenient to use this method for disassembled components. The swap diagnosis method can avoid the performance degradation of hydraulic components caused by blind disassembly. For the above faults, if there is no need to check the replacement method, but directly remove the suspected main safety valve and disassemble it, if there is no problem with the component, its performance may be affected after reassembly.

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3. Instrument Measurement and Inspection Method

The fault point of the system is judged by measuring the pressure, flow and oil temperature of the hydraulic oil in each part of the hydraulic system. In general on-site inspections, the failure of the hydraulic system is often manifested as insufficient pressure, which is easy to detect; while the flow detection It is more difficult, and the size of the flow can only be roughly judged by the speed of the action of the actuator. Therefore, in the field inspection, more methods are used to detect the system pressure.


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