Yanmar 3GM30f Raw Water Pump

[carlager]

I have have unmounted the raw water pump (type Johnson Pump F4B-903) on our Yanmar 3GM30f.


I can see a black O- ring on the shaft in the weephole (re. the attached photo).

Is this O-Ring placed right ?

 

[Ken13559]

Yes. Don't know what it is for. Mine in same place.

 

[kloudie1]

That serves as a "flinger" so that any water that may leak past the pump water seal (left side of picture) is flung off the shaft so that it does not get in the pump bearing cavity (right side of picture). it should turn with the shaft.

 

[carlager]

Thank you for your answer.