Water pump is one of the important components of automobile engine cooling system. The function of water pump is to pressurize the coolant to ensure its circulating flow in the cooling system and accelerate the heat dissipation. As a long-term operation of the device, in the use of the process, the pump will also fail, how to repair these failures?

Check whether the pump body and pulley are worn and damaged, and replace them if necessary. Check whether the pump shaft is bent or not, the wear degree of the journal and the thread of the shaft end are not damaged. Check whether the blades on the impeller are broken or not, and whether the wear of the shaft hole is serious. Check the abrasion degree of water seal and bakelite gasket. If it exceeds the use limit, replace new parts. Check the wear condition of the bearing and use the meter to measure the clearance of the bearing. If the clearance exceeds 0.10mm, the new bearing should be replaced.

There are several common failures of water pumps: leakage, loose bearing and insufficient pump water.

There are obvious marks when water leakage is caused by cracks in pump shell. When cracks are light, they can be repaired by bonding method and replaced when cracks are serious. When pumps are normal, the drain holes on Shuidongke should not leak. If the leakage holes show poor sealing, the reason may be that the sealing surface is not contacted closely or the water seal is damaged, the water pump should be decomposed for inspection and the water seal surface should be cleaned or more. Change the water seal.

When the engine idles, if the pump bearing has abnormal sound or the pulley rotates unbalanced, it is generally caused by the loose bearing; after the engine is out of flameout, the pulley is pulled by hand to further check its width; if there is obvious loose, the pump bearing should be replaced; if the pump bearing has abnormal sound, but the pulley is not obviously loose by hand, it may be caused by poor lubrication of the pump bearing, and the grease nozzle should be used. Add grease.

The insufficiency of pump water is usually due to blockage of water channel, slippage of impeller and shaft, leakage or slippage of transmission belt. Troubles can be eliminated by dredging water channel, reassembling impeller, replacing water seal and adjusting the tightness of fan transmission belt.

Repair of water seals and seats: If water seals are worn out and grooved, they can be ground down with abrasive cloth and replaced if they are worn out excessively; if water seals have rough scratches, they can be repaired with flat reamers or on lathes. New water seal assemblies should be replaced during overhaul. Welding repair is allowed when there are the following damages on the pump body: cracks that do not extend to the bearing seat holes within 30 mm in length; cracks on the flange joining the cylinder head; and damages on the oil seal seat holes. The bending of the pump shaft should not exceed 0.05 mm, otherwise it should be replaced. Damage of impeller blade should be replaced. Serious wear of pump shaft aperture should be replaced or repaired by insert sleeve. Check whether the pump bearings are flexible in rotation or have abnormal noise. If there are problems with the bearings, they should be replaced.