The accumulation of dirt in the hydraulic heavy excavators is the most common cause for the malfunction of the construction equipment, especially with the increase in pressure and precision in operation. It's necessary to be particularly careful, on the occasion of filling hydraulic oil and during the disassembling or assembling of the equipment.
First of all, be careful of the operating environment. Always avoid adding hydraulic oil, replacing filters, or maintaining the heavy excavator in extreme weather, such as rain or high winds, for preventing the dust from getting into. Stay away from the places with a lot of dust when parking the equipment. Since it is difficult to confirm the performance after the repairs, it is advisable to use the unit exchange. The disassembly and maintenance of hydraulic heavy excavator should be carried out in a specially prepared dust-proof workshop, and a special equipment should be used for testing performance. Do not let any dirt or dust get in when refilling with hydraulic oil. Always keep the oil filler and the area around it clean, and also employ the clean pumps and oil containers for usage. By using an oil cleaning device, the dirt collected during storage could be filtered out, which is an even more effective method.
When heavy excavator's hydraulic oil or other liquid is warm, it flows smoothly and the dirt can also be drained out easily from the circuit, so it is strongly suggested to the oil when it is still warm, to make sure as much as possible of the waste hydraulic oil be drained out from the heavy excavator, specifically, from the hydraulic tank, the filter or the drain plug in the circuit.) If any waste oil is left, the contaminants and sludge in it will mix with the new oil and then shortens the life for usage.
After disassembling and assembling the heavy excavator, or changing the oil, use flushing oil to remove the contaminants, sludge, and waste oil from the hydraulic circuit. Normally, flushing is carried out twice: primary flushing is carried out with flushing oil, and secondary flushing is carried out with the specified hydraulic oil.