Excavator main pump abnormal noise exclusion method is what?

After a PC200-6 full hydraulic excavator is started, the working device can realize various actions, but the main pump emits abnormal noise. Preliminary analysis, that pump is empty or oil mixed with air caused. Therefore, first adjust the working device to the oil level detection position, check the hydraulic oil tank found in the oil level below the low, is a lack of oil position. Upon inquiry, the driver knows that the sealing ring of the high-pressure tubing leading to the rodless cylinder cavity of the arm cylinder has been replaced due to oil leakage during the work, but the oil level has not been checked in time after the replacement. So, first of all, to the hydraulic tank refueling to the standard oil level, the test machine showed abnormal noise, although reduced, but still exists; then, after the main pump exhaust valve to vent the main re-test machine and found that abnormal noise exists , Indicating that this noise can not be completely caused by the pump suction empty. Next, the hydraulic oil tank suction filter and return filter were checked and found that the suction filter black, sludge, and the back of the filter stuck with brown metal particles, for which the replacement of the filter; taking into account the oil filter On the sticky brown metal particles, so the main pump oil released and checked and found that there are brown metal particles; the same time, disintegration check the main pump found that the piston, with flow plate, swashplate and other non-destructive phenomenon, and Slides produce wear. After its replacement, the assembly was carried out strictly according to the requirements, the hydraulic system was cleaned and the oil was changed. When the testing machine was started again, the abnormal noise disappeared and the fault was eliminated. Under normal circumstances, the main pump may cause abnormal noise around the following reasons: the hydraulic pump is not enough to cause the main pump suction; suction pipe mixed with air; suction filter plugged lead to the main pump suction; internal pump main wear and tear, resulting in the main pump work Abnormal noise appears. In this case, the abnormal noise is due to insufficient hydraulic oil and wear and tear of the main pump shoe. The reason is: do not check the oil level after replacing the seal, resulting in insufficient hydraulic oil to make the main pump produce suction phenomenon; when the oil mixed with air flows through the main pump, the shoe can not float or float at some instant Insufficient, resulting in slide between the swashplate and can not form a good lubricant film, so that the wear of the slide, eventually leading to abnormal work of the main pump noise.