(1) When the Submersible Sewage Pump was installed, the water seal seat assembly was not installed in place, causing the water pump to continue to leak. Since there is a water ring on the pump shaft corresponding to the inspection hole, when the water seal leaks, the cooling water will be thrown out and dripping out from the inspection hole of the pump when the water seal leaks. Cooling water flows into the bearing to destroy the lubrication. In addition, when replacing the water retaining ring, care is not taken to remove the inability to combine and seal the pump body and the pump cover, which will also cause the water pump to leak.
　　
　　(2) The working environment of construction machinery is harsh, which easily causes uneven wear of the bakelite gasket and the end face of the bushing; the spring is soaked in water for a long time, it is easy to rust, the elasticity decreases, and it can also cause water leakage.
　　
　　(3) Forgetting to discharge water or the water is not clean in winter, and the temperature is too high when the water is discharged, and the water vapor in the cooling system freezes after condensation, which may cause the water pump body to freeze and crack and cause water leakage.
　　
　　(4) The machine is old, and the parts in the water seal are worn, rusted and aging, which are also the reasons for the water pump leakage. When the construction machinery is parked for a long time, the bakelite gasket is deformed due to dryness and shrinkage due to the lack of cooling water in the engine; after adding water, the bakelite gasket will expand but cannot completely return to its original state, which will inevitably cause a small amount of water leakage. In addition, for the newly installed water pump, the bakelite gasket and the cast iron bushing have not been completely run-in, which will also cause a small amount of water leakage in the water pump.