Water leak on Yanmar 2GMF raw water pump

[Charles Erwin]

Reg M

Note the circlip at the threaded end of the shaft. Remove that clip and the bearing comes off toward the threaded end. The second bearing follows the first. I have seen some of these pump shafts with a stop shoulder - which is actually part of the shaft - so you cannot push the bearing off toward the stop shoulder (the impeller end.) Some have a circlip between the first bearing and its twin (second) bearing. Obviously that clip needs to be removed before the second bearing is pushed off the shaft. In any case mark or measure the position of the bearings on the shaft. That way you can put the new ones at the same position as the old ones.

When installing new bearings be sure to push on the inner race so you do not damage the ball section. A 7/16 deep socket is perfect as a pusher.

Edit: If the shaft is scored where the lip seal rides a new seal will leak. So let us know on that

Charles

 

[Glenn2002]

Excellent post. I have noticed a small amount of fluid under the engine but haven't had the time to really investigate yet. I am suspecting this could be the cause.
I have a 1984 so I am wondering if it will come apart or not. Will try the rebuild first, and if its not workable, will look for the European version. One question, any chance you could post the part number at Depco? I am looking but there doesn't seem to be a Yanmar pump section. Will keep looking.

Update: Think I found it, can you just confirm this is the one, check image, pretty sure it is. Thanks

 

[Reg M]

I finally got the bearings off (there was a circlip between them) and after getting the new ones back on and attempting to install the water seal I discovered the seal was just a little too big. The parts fisch is a bit deceiving because it shows a blow-up section for the seal indicating number 22 and pointing to the seal area with the word "old". As it turns out, if you have the old type pump like I do, you need parts 42, cover plate, 28 rubber washer (my terminology - the fisch calls it "piece") and 25 seal. If you have the new type I guess you only need the part 22 which is a seal and it is a bit larger than part 25. If you are doing a rebuild I would suggest taking the pump apart before ordering the parts, that way you can see the parts you have and order appropriately. I will now have to order another seal and I hope it gets here before haulout day so I can motor to the haulout dock!!!

 

[Tom H31]

There is a snap ring between the bearings. You have to use a bearing puller to get the first bearing off the shaft. The Yanmar service manual has a drawing showing all the parts and how they go together so you reassemble the pump properly.

 

[Reg M]

I didn't have a bearing puller so I improvised - I made up a piece of hardwood about two inches wide, 1/2 inch thick and about six inches long. I then turned that on its side and tapered it from a point at the end to full thickness of a half inch at about three inches back from the end. I then laid it flat and cut a half inch gap out of the center measuring about an inch back from the end, looks sort of like a tuning fork. I then used a hammer to drive this invention down between the bearings. Worked like a charm. After that I just laid two screwdrivers between the bearings across a partially open vice and tapped the shaft out. The second bearing was then pretty straight forward. Still waiting for my new seal.

 

[Reg M]

Got my new seal yesterday and put the pump back together and reinstalled on the boat. Works great except I have a very slight weep at the gasket because I used the old gasket but thats OK because I plan to remove the impeller for the winter after haulout anyway and I'll install a new gasket in the spring. Don't you just love it when a plan comes together!!!