1) rotating in the opposite direction and provides direction;

2) suction line is not tight, check valve stuck;

3) oil pump bad seal between the pump body and cover;

4) not enough oil in the fuel tank;

5) pump parts seriously worn out;

6) oil filter screen is blocked.

Practical work should be carried out according to the specific circumstances of different treatments, should pay special attention to oil pipelines in the repair seal, as well as gear oil pump seal between the pump and the pump cover, suction side if the bad seal, oil pumps imported leak into the air, causing pump time, nature is not oiled.