As the temperature gradually rises, many friends report that the excavator has a problem that makes the excavator masters have a headache, that is, the phenomenon of high hydraulic oil temperature; if the hydraulic oil temperature is not handled in time, the hydraulic pump and master control will be reached in the long run. The internal leakage of the valve and each working device must be repaired or replaced when it is serious.
A Kobelco SK250-8 hydraulic excavator has been working for 8000 hours. The temperature of the hydraulic oil has been high recently. The hydraulic temperature can reach 80 ℃ for half an hour. If you continue to work, the temperature of the hydraulic oil will continue to increase until the alarm.
Inspection and analysis:
1. The pressure, flow and variable performance of the hydraulic pump of the excavator are normal, and no problems have been found in the hydraulic oil tank and the oil inlet pipeline.
2. When checking the hydraulic oil radiator, the wind power of the cooling fan is obviously weak. This fan is directly driven by a hydraulic motor, and the hydraulic oil from the hydraulic motor comes from a special hydraulic pump for cooling the front gear box of the engine.
3. Is there a problem with the cooling hydraulic pump or motor? We tested the pressure into the fan drive motor. The engine speed is 2000 rpm and the value is 148kg / cm2. It follows that there is no problem with the fan drive motor and the hydraulic pump. Checking the air duct again revealed no obvious problems.
4. The above inspection can preliminarily determine that there is a problem with the fan blade. However, the fan blade was expensive (the unit price at the time was 13000.00 yuan) and no replacement parts could be found. We further verified the judgment and measured the fan speed at 1990 / min. So it was concluded that there was a problem with the fan blade, and the temperature of the hydraulic oil returned to normal after the order was replaced.
Engine water temperature is too high Let me talk about the problem of high engine water temperature. Inaccurate ignition timing, insufficient engine power, and failure of the cooling system can cause the engine water temperature to be too high. In the excavator before the common rail EFI diesel engine, because the hydraulic oil radiator is installed upstream of the cooling air of the water tank, overheating of the hydraulic oil will also cause the water temperature to be too high.
