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What is the Principle of Selection and Replacement of Hydraulic Oil for Excavators?

According to relevant statistics, about 70% of hydraulic system failures of excavators are caused by the improper selection of hydraulic oil, careless use, and untimely replacement. Therefore, the correct and reasonable selection and replacement of hydraulic oil is an important condition for exerting the working performance and economic performance of the excavator and prolonging the service life of the hydraulic system and its components.


hydraulic oil for excavators


Generally, the hydraulic equipment manufacturer stipulates the type, grade, and viscosity level of the hydraulic oil used in the equipment system in the equipment manual or user manual. The user should first select the hydraulic oil according to the equipment manufacturer’s recommendation. But sometimes, you need to choose hydraulic oil by yourself, how to choose it? As a professional editor of LandTopMall, I will introduce you to the principles of selecting hydraulic oil for excavators, as follows:

Environmental Conditions

According to the environmental temperature characteristics of the excavator in the underground, water, indoor, outdoor, cold area, or in the severe cold area with large temperature changes, and whether there is a high-temperature heat source or an open flame nearby, the hydraulic oil is reasonably selected.


Working Conditions

Oil pump type, working pressure, temperature, speed, system operation cycle and working characteristics, etc. If the working conditions have higher requirements on the speed of the actuator, the system pressure, and the accuracy of the action of the mechanism, the requirements on the wear resistance and bearing capacity of the hydraulic oil are also higher. According to the possible working temperature of the system, the continuous operation time and the sanitation of the working environment, etc., the viscosity, high-temperature performance, and thermal stability of the oil must be paid attention to when selecting an oil, to reduce the formation and deposition of sludge, etc.


The Size of the Fuel Tank

The smaller the fuel tank, the higher the requirements for the oil’s anti-oxidative stability, extreme pressure and anti-wear properties, air release properties, and filtration properties.


hydraulic oil for excavators


Hydraulic Parts

Different hydraulic components have a minimum configuration requirement for the hydraulic oil used. Therefore, when selecting hydraulic oil, attention should be paid to the type of hydraulic components and the compatibility of the materials used in seals and coatings or paints with hydraulic oil to ensure that each movement of The auxiliary lubrication is good so that the components can reach the design life and meet the performance requirements. If your excavator needs to replace such accessories, you can call: (+852) 63548665 to consult, our accessories experts will give you the best quality advice and service. In addition, you can also log in to LandTopMall’s official website to purchase by yourself.


Properties of Hydraulic Oil

Check its supply, viscosity, quality, use characteristics, the scope of application, and compatibility with system and component materials to see if each index can fully meet the use requirements.



It is necessary to comprehensively consider the price and service life of hydraulic oil, as well as the maintenance and safe operation cycle of the hydraulic system, and focus on brands with good economic benefits.


The hydraulic system with higher temperature and pressure should use hydraulic oil with a higher viscosity to obtain better lubricity; on the contrary, if the temperature and pressure are lower, lower viscosity should be used, which can save energy consumption. In addition, it should also be considered that the working viscosity of the hydraulic oil at the lowest temperature of the system should not be greater than the maximum viscosity of the pump. Select the appropriate hydraulic oil, but also correct hydraulic oil replacement. In the process of replacing hydraulic oil, the following points need to be paid attention to:


  1. Drain the original hydraulic oil before replacing, and check the oil return filter element, oil suction filter element, and pilot filter element to see if there are iron filings, copper filings, or other impurities. . LandTopMall sells various types of excavator accessories, filter cartridges for Yanmar wheeled excavator has high sales and wide acclaim at LandTopMall.


  1. When changing hydraulic oil, all hydraulic oil filter elements (oil return filter element, oil suction filter element, pilot filter element) must be replaced at the same time, otherwise, it is equivalent to not changing the hydraulic oil.


  1. Identify the hydraulic oil label. Hydraulic oils of different labels and brands are not mixed, which may react and deteriorate to produce floccules. It is recommended to use the oil specified for this excavator.


  1. The oil suction filter must be installed before refueling. The nozzle covered by the oil suction filter element directly leads to the main pump, and the impurity entering will accelerate the wear of the main pump in light, and the pump will be beaten in heavy.


  1. Refuel to the standard position. There is generally an oil level gauge on the hydraulic oil tank, see the gauge. Pay attention to the parking method, generally, all cylinders are fully retracted, that is, the forearm and bucket are fully extended and landed.


  1. After adding oil, pay attention to the main pump to exhaust air, otherwise the whole vehicle will not move temporarily, the main pump will make abnormal noise (air sonic boom), and the air pocket will damage the main pump. The air exhaust method is to directly loosen the pipe joint on the top of the main pump and fill it up directly.

LandTopMall is an experienced accessory sales website, our accessories experts will be at your service throughout the process, providing you with the most useful advice and high-quality products. Welcome to inquire!


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