1, the pump is not absorbent or not drained. Caused most of this failure is due to the end of the valve stuck, part of the blockage of water filtration, suction height is too high or suction pipe leakage and so on. Should be checked one by one, respectively, to repair the end of the valve, remove the blockage, to correct the steering and other processing. 2, pipeline leakage or leakage. Mostly because the nut did not tighten. If the leak is not serious, you can smear grout, wet mud or soft soap at the leak; if the joint leaks, wrench can be used to tighten the nut. Severe water leakage, leaks, you must re-disassembly. 3, the pump violent vibration. It may be that the rotor is unbalanced or that the coupling is bad. Sometimes bearing wear, bending, rotating parts loose parts, rupture, pipe support is not strong will cause vibration. Should be adjusted, reinforcement, inspection or replacement. 4, impeller broken. Damage is not, you can repair. Serious damage should be replaced or plated with cemented carbide. Completely damaged, should remove the impeller, sent to the repair shop repair. 5, pump shaft bending. Mostly due to the impact load, too tight belt pulled, the installation is not correct and so caused. If the bend is not serious, manual screw can be used for correction, but the force can not be excessive, to prevent a complete break.