What are the precautions when replacing the entire hydraulic fluid of an excavator

(1) The steps for replacing oil in the fuel tank, hydraulic plunger pump, boom cylinder, stick cylinder, bucket cylinder, swing motor, and left and right travel motors cannot be changed. Due to different projects, only the corresponding parts can be manipulated to make them move, in order to avoid any operational errors.

(2) Quality requirements for hydraulic oil: The service life of excavators is directly related to the quality of hydraulic oil. It is necessary to choose hydraulic oil that meets the quality standards certified by the American Society of Engineers. This type of hydraulic oil has a stable viscosity index at 40 ° C to 100 ° C. When replacing, the same brand of hydraulic oil must be used.

(3) Requirements for viscosity of hydraulic oil: There are three types of anti-wear hydraulic oil: N32HL, N46HL, and N68HL. Excavators with a service life of 1000 hours should use N46HL+N68HL anti-wear hydraulic oil (50% each). Apply N68HL anti-wear hydraulic oil to excavators with an operating time of over 15000 hours.

(4) Service life of hydraulic oil: The service life of hydraulic oil is 4000~6000 hours, approximately two years. In spring and autumn every year, there is a large temperature difference between day and night. After the excavator stops working at night, the oil inside the hydraulic oil tank is high temperature, and the air outside the tank is low temperature. When the hot air inside the tank meets the cold air outside the tank, it condenses into water droplets at the top of the tank and falls into the hydraulic oil. Over time, water will be mixed in the hydraulic oil. Subsequently, it evolved into acidic substances that corrode the metal surface. Under the dual effects of mechanical operation and pipeline pressure impact, metal particles that fall off the metal surface will mix with hydraulic oil. Large metal particles will be filtered out, while particles smaller than 10 μ m cannot be filtered out by hydraulic filter cartridges. The mixed abrasive particles that cannot be filtered out in hydraulic oil will further aggravate the re wear of the metal surface.

(5) Selection of hydraulic oil filter element: The required filtration accuracy is 50% of 10 μ m, the pressure range is 1.5 MPa, the rated flow rate is 40-400 L/min, and the recommended replacement time is 500 hours.

(6) All disassembled oil pipes must have their seals replaced. When connecting the O-ring, thread sealant should be applied to the threaded surface to prevent leakage. Source: （Liehuang used excavator） https://www.lh-usedexcavator.com/