The lubrication system of diesel engine is mainly composed of oil pan, oil pump, oil filter, radiator, main oil passage, oil distribution passage, low oil pressure alarm sensor, high oil temperature alarm sensor, pressure limiting valve and bypass valve. There are many reasons for the low oil pressure of excavator. This article will list several reasons one by one for reference only.
1. Improper oil grade
Different engine oil brands should be added in different seasons. If the selected engine oil is inappropriate or inferior, the leakage will be increased and the pressure will be reduced due to low viscosity when the engine is running. The engine oil shall be selected correctly and reasonably to adapt to different models or seasons.
2. The oil filter is blocked
When the oil filter is blocked and cannot flow, the bypass valve on its base is opened, and the oil directly enters the main oil passage without filtering. If the opening pressure of the bypass valve is set too high, when the oil filter is blocked, it cannot be opened in time, the oil pump pressure will rise, the internal leakage will increase, the oil supply to the main oil passage will decrease, and the oil pressure will decrease. Ensure that the oil filter is clean. Correctly adjust the opening pressure of the bypass valve, timely replace or repair the damaged components or mating surfaces, and restore its normal working performance.
3. The filter collector is blocked
Under normal conditions, the oil pressure should be higher when the throttle is large than when the throttle is small, but sometimes abnormal conditions will occur. If the oil is too dirty and sticky, it is easy to block the filter collector. When the engine runs at a low speed with a small throttle, the oil pressure is normal because the oil absorption of the oil pump is small and a certain pressure can be established in the main oil passage. However, when the accelerator is increased for high-speed operation, the oil absorption of the oil pump will be significantly reduced due to excessive resistance of the filter collector, so the indication of the oil pressure gauge will decrease due to insufficient oil supply in the main oil passage. Clean the suction filter or change the oil.
