If the water pump fails or is damaged during use of the car, the following inspections and repairs can be done
(1) Inspection of water pump
Check the pump body and pulley for wear and damage, and replace if necessary. Check whether the water pump shaft is bent, the degree of shaft neck wear, and whether the thread of the shaft end is damaged. Check whether the blades on the impeller are broken, and whether the shaft hole is severely worn. Check the degree of wear of the water seal and bakelite gasket, and replace with new ones if it exceeds the service limit. Check the wear of the bearing. Use a meter to measure the gap of the bearing. If it exceeds 0.10mm, replace the bearing.
(2) Repair of water pump and seat
After the pump is taken out, it can be decomposed in order. After disassembly, the parts should be cleaned, and then inspected one by one to see if there are defects such as cracks, damage, and wear. If there are serious defects, they should be replaced.
Repair of water seal and seat: If the water seal is worn and grooved, it can be smoothed with emery cloth. If it is worn out, it should be replaced; if the water seal seat is rough or scratched, it can be repaired with a flat reamer or on a lathe. Replace the water seal assembly with a new one during overhaul.
Welding repair is allowed when the pump body has the following damages: the length is less than 30mm and does not extend to the cracks of the bearing seat hole; the flange joint with the cylinder head has broken parts; the oil seal seat hole is damaged. The bending of the water pump shaft must not exceed 0.05mm, otherwise it should be replaced. Damaged impeller blades should be replaced. The shaft bore of the water pump is seriously worn and should be replaced or repaired.
Check whether the bearing of the water pump rotates flexibly or has abnormal noise. If there is a problem with the bearing, it should be replaced.
After the pump is assembled, turn it by hand, the pump shaft should be free from jamming, and the impeller and pump casing should be free from rubbing. Then check the water pump displacement. If there is any problem, check the cause and eliminate it. If the water pump fails, the coolant will not be able to reach the corresponding place, and its performance will not be effectively exerted, which will eventually affect the working condition of the engine. Therefore, the inspection of the water pump must be strengthened.
