① Check the pump body and pulley for faults or damage, and replace if necessary;

②Check whether the pump shaft is bent, the degree of wear of the journal, and whether the shaft end thread is damaged

③ Check whether the blade on the impeller is broken or the shaft hole is seriously worn

④Check the degree of water seal and bakelite gasket, if it exceeds the usage limit, you should replace with new accessories

⑤Check the bearing wear and measure the bearing clearance. If it exceeds 0.1mm, the new bearing should be replaced