The replacement cycle of the hydraulic oil for small excavators is not fixed. It is generally recommended to replace it every 500 - 1000 working hours or every six months to one year. However, the actual replacement time is influenced by several factors.
High - temperature Environment: In hot regions or when operating under high - temperature conditions for an extended period, the temperature of the hydraulic oil remains persistently high. This accelerates the oxidation of the hydraulic oil, causing its viscosity to decrease, its performance to deteriorate, and the additives to become ineffective more quickly. For example, in open - pit mines in summer where the ambient temperature exceeds 40°C, the hydraulic oil is prone to deterioration, and it may need to be replaced every 500 hours.
Dusty Environment: In construction sites with a lot of dust, dust is likely to penetrate the hydraulic system. Once it mixes with the hydraulic oil, it will intensify the wear of internal components and block the filters and oil passages. For instance, in urban demolition sites where there is a lot of dust, the hydraulic oil is at a high risk of contamination, and it may need to be replaced every 500 - 700 hours.
Humid Environment: In environments with high humidity or during underwater operations, moisture can easily enter the hydraulic oil. This will cause the hydraulic oil to emulsify, reduce its lubrication performance, and corrode metal components. For example, when working in a marshy area, the hydraulic oil is greatly affected by moisture, and the replacement cycle should be shortened to 500 - 700 hours.
High - intensity Operation: If a small excavator operates continuously for a long time under high - load conditions, the hydraulic system is frequently subjected to high - pressure impacts. For example, in a water conservancy project where earthwork is continuously excavated, the hydraulic oil deteriorates rapidly under such harsh working conditions. To ensure the stable operation of the system, it may need to be replaced every 500 - 700 hours.
Frequent Start - stop: Frequent starting and stopping of the excavator result in large fluctuations in the pressure of the hydraulic system, and the oil temperature changes drastically, accelerating the aging of the hydraulic oil. For example, in a narrow space where frequent loading and unloading operations are carried out, the replacement cycle of the hydraulic oil should also be around 500 - 700 hours.
High - quality Hydraulic Oil: High - quality hydraulic oil has an excellent additive formula, with strong anti - oxidation, anti - wear, and anti - contamination capabilities. When using this type of hydraulic oil, under normal working conditions, the replacement cycle can be extended to 800 - 1000 hours.
Ordinary Hydraulic Oil: Hydraulic oil of average quality has relatively poor performance stability. Under the same working conditions, its rate of deterioration is relatively fast, and the replacement cycle may be between 500 - 800 hours.
After the operation, it is also necessary to regularly check the appearance and performance of the hydraulic oil. If the color becomes darker, turbid, has an abnormal smell, or the viscosity is abnormal, even if the recommended replacement time has not been reached, it should be replaced in a timely manner to ensure the efficient and stable operation of the hydraulic system of the small excavator.
