During the working process of the loader, if the oil pressure is lower than 0.2MPa (or fluctuatingly high and low with the engine speed), it should be shut down immediately to find the cause, and the work can be continued after troubleshooting, otherwise it will cause burning and pulling. Cylinder and other major mechanical accidents. The main reasons for low oil pressure are now introduced as follows.

(1) The amount of oil is insufficient

If the amount of oil is insufficient, the amount of oil pumped by the oil pump will decrease, resulting in a drop in oil pressure and aggravating the wear of the crankshaft and bearings, cylinder liners and pistons.

(2) Engine temperature is too high

If the engine temperature is too high, it will not only accelerate the oil aging and deterioration, but also easily make the oil thin, causing the oil pressure to drop.

(3) The oil pump stops or the pump oil is insufficient

The drive gear of the oil pump and the fixed pin of the drive shaft are broken or the mating key falls off, and the oil pump sucks in foreign matter and jams the oil gear, which will stop the oil pump and reduce the oil pressure to zero.

When the gap between the oil pump shaft and the bushing, the gap between the gear end face and the pump cover, the tooth side gap or the radial gap exceeds the allowable value due to wear, it will cause the pump oil to decrease, resulting in the consequence of a drop in the oil pressure.

(4) The clearance between crankshaft and connecting rod bearing is too large

After long-term use of the engine, the clearance between the crankshaft and the connecting rod bearing will gradually increase, and the oil pressure will also decrease.

(5) Oil filter is clogged

When the oil cannot flow due to the clogging of the oil filter, the safety valve on the base of the oil filter is opened, and the oil enters the main oil passage directly without filtering. If the opening pressure of the safety valve is adjusted too high and the oil filter is blocked, the safety valve cannot be opened in time, so the oil pump pressure increases, the internal leakage increases, and the oil supply of the main oil passage decreases, causing the oil pressure to drop.

(6) The oil return valve is damaged or malfunctioning

If the oil return valve spring is fatigued and softened or adjusted improperly, the mating surface of the valve seat and the steel ball is worn or jammed by dirt and the closing is not tight, the oil return will increase significantly, and the oil pressure of the main oil passage will also decrease.

(7) Oil radiator or pipeline leaks

Oil leakage from the oil radiator and pipelines will cause the oil pressure to drop. If the pipeline is blocked by dirt, the oil flow rate and oil pressure will decrease due to the increase of resistance.

(8) The oil pressure sensor fails or the oil pipe is blocked

If the oil pressure sensor fails, or the oil pipe from the main oil passage to the oil pressure sensor is not flowing smoothly due to accumulation of dirt, the oil pressure gauge will display the oil pressure drop.

(9) The suction pan is blocked

If the oil is too dirty or sticky, it will easily block the suction pan. When the engine is running at low throttle and low speed, the oil pump suction is not large, and the main oil passage can still build up a certain pressure, and the oil pressure will be normal; but when the throttle is increased at high speed, the oil suction of the oil pump will be excessive due to the resistance of the suction cup Large and obvious reduction, which in turn causes the display value of the oil pressure gauge to drop.

(10) Wrong oil grade or unqualified quality

Different types of engines must be added with different oils, and the same type of engine should also use different brands of oil in different seasons. If the oil grade is wrong, the oil will leak too low when the engine is running, which will lower the oil pressure.

(11) Pressure regulator setting pressure is too low

If the setting oil pressure of the pressure regulating valve is low, the oil cannot be effectively delivered to the lubrication parts, and mechanical failure occurs. If the oil pressure is too high, it will increase oil consumption, load the oil pump and lubrication parts, damage the oil circuit seals and cause oil leakage.