The Back Story

April 8, 2013

Yanmar 3GM30F Raw Water Pump - Rebuild

Just before we left to go sailing on Moreton Bay, I rebuilt the raw (sea) water pump with spare parts I had bought in San Francisco, some 2-1/2 years ago.  New bearings, a lip seal, a new impeller, etc.

If you take your old bearings and lip seal to a bearing supply house they can supply generic replacements for about 1/4 of the cost of Yanmar parts.  Just make sure your lip seal has a s.s. spring or an O-ring.  It's not hard work really to do the rebuild, once you realize the 2 bearings have a circlip between them and you have to seperate them to get them off the shaft.

And when you put the pump back togther - the pulley is not symmetric.  It's dished on one side. If you put the pulley on with the wrong face facing the pump, the V-belt won't line up.  At all. Though you can convince yourself that all is well if you're trying to go sailing for a long weekend.  And motor for many hours with the pump working with a V-belt that is totally off by about 1 cm or more.  When you put the pulley on the CORRECT way it looks much nicer.


8 comments:

  1. Anonymous11:38 AM

    makes one wonder how you found that out ........... I've never done that.

    ReplyDelete
  2. You can get a brand new pump at half the cost of the original Yanmar. Try www.depcopump.com. I got one for our 3GM. Just add grey paint. They are in fact Johnson pumps, nothing really Yanmar-ish about them (except the price).

    ReplyDelete
  3. It is truly a great and helpful piece of information.
    I am satisfied that you simply shared this useful information with us.
    Please stay us informed like this. Thanks for sharing. I know something information, to know you can click here
    water softener
    water filter

    ReplyDelete
  4. Anonymous12:30 PM

    jsut rebuilt mine after I noted dripping water from the housing side, not the impeller plate side.
    Bearings were perfect still, new seal installed (a single yanmar part that is actually 3 parts) and new impeller and o-ring for the palte, and it is perfect! Bought a spare (as I do every time I need a replacement or maintainence part).
    Next up the exhaust/mixing elbow...

    ReplyDelete
  5. This is really resourceful piece of information.
    raw water pumps
    waste water pumps


    ReplyDelete
  6. This comment has been removed by the author.

    ReplyDelete
  7. Veryy thoughtful blog

    ReplyDelete