Home Products News Contact Us
Home > Supports > Diesel Generators > The Frequently Invalid Phenomenon of Generator Water Pump

The Frequently Invalid Phenomenon of Generator Water Pump

Jul. 13, 2021

The working principle of the water pump is to transfer the mechanical energy of the prime mover or other external energy to the liquid to increase its energy, thereby transporting the liquid: water, oil, acid and alkali liquid, emulsion, suspoemulsion and liquid metal, etc.; liquid and gas mixture; containing A liquid that suspends solids. There are also many uses of water pumps, with different structural forms. Starlight has sorted out the common failure modes of water pumps on generators for everyone.

electric generator.jpg

Water pump inspection and repair


The common failure modes of the water pump on the generator are: axial looseness of the impeller, wear of the shaft and bearing, leakage of the water seal, and rupture of the pump casing and impeller.


1. Disassembly and cleaning of the pump

The disassembly and cleaning of the water pump can be roughly divided into:

1) Remove the fixing screws of the fan and remove the fan.

2) Remove the fixing bolts of the fan belt hub, and then use a pliers or a press to remove the fan and the belt hub from the water pump shaft.

3) Remove the impeller fixing bolts and the bearing lock ring, and then press the water pump shaft forward toward the center of the impeller, and remove the impeller (if there is no press, you can also use a copper rod or iron rod with a smaller outer diameter than the water pump shaft to cushion the soft The quality metal washer is hammered out by hand, but this time you should pay attention: the force should be appropriate).

4) Remove the water blocking ring, bakelite pad, rubber sleeve and spring from the impeller.

5) Clean the parts according to the cleaning requirements and methods.


2. Inspection and repair of water pump

The inspection and repair of the water pump includes the following six aspects:

1) Check the pump casing and impeller. There should be no serious cracks in the pump casing. The crack length should not exceed 30mm, and it should not extend to the edge of the bearing housing hole. If the above conditions are met, it can be repaired by welding with brass alloy electrodes. Preheat the pump casing before welding to prevent deformation after welding. If the above conditions are not met, the pump casing should be replaced. Only one impeller is allowed to be damaged. If more than two are damaged, it must be replaced.

2) Check the fit of the pump shaft and the impeller hole. The pump shaft and the impeller hole are interference fit. If the impeller and the shaft fit loosely, they should be repaired. The repair process is generally to increase the size of the shaft by hanging tin. The specific technical requirements are: After the impeller is installed on the shaft, the end of the impeller should be 0.1*0.5mm higher than the pump shaft.

3) Check the situation when the water pump pulley is running. When the diesel engine (land-use generator set drive type) is running, the water pump pulley should not be severely swayed. If the above phenomenon exists, there may be two reasons: one is the looseness of the bearing, and the other is the wear of the belt pulley, the tapered sleeve, and the half-round key. The shaft and bearing of the water pump are worn, the axial movement cannot exceed 0.30mm, and the radial movement cannot exceed 0.05mm, otherwise the bearing should be replaced with a new one. If the tapered sleeve and half-round key of the pulley are worn out, they should be replaced.

4) Check the bakelite ring seat in the water pump housing. Check the bakelite ring seat in the water pump housing for spots or abrasion marks. If there are, you can file it with a file or light it with a machine unit.

5) Check the wear of the bearing. The radial clearance cannot exceed 0.10mm, and the axial clearance cannot exceed 0.30mm, otherwise the bearing should be replaced with a new one

6) Check the water seal. If the bakelite pad is worn and grooved, the spring is too soft, the rubber sleeve is swollen and damaged, etc., all should be replaced with new ones. If the bakelite mat is not severely worn, it can be used after adjusting the surface or smoothing it.


Starlight recommends that when the diesel generator set has been operating for 550 hours, in addition to the first-level technical maintenance items, it is also necessary to check the fuel injector, fuel injection pump, adjust the valve clearance and fuel injection advance angle; Check the intake and exhaust; Check the sealing condition of the water pump; Check the water sealing condition of the cylinder liner sealing ring; Check various radiators; Tighten the parts of the diesel engine and generator; Clean the pipeline.


More information please send email to sales@dieselgeneratortech.com

Contact Us
  • Add.: No. 10 Kechuang Road, High tech Zone, Nanning, Guangxi, China
  • Tel.: +86 771 5805 269
  • Fax: +86 771 5805 259
  • Cellphone: +86 134 8102 4441
                    +86 138 7819 8542
  • E-mail: sales@dieselgeneratortech.com
Follow Us

Copyright © Guangxi Dingbo Generator Set Manufacturing Co., Ltd. All Rights Reserved | Sitemap

Update cookies preferences
Contact Us