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Yanmar 2gm raw water impeller removal?

Discussion in 'Mid-Size Boats' started by pateco, Jul 22, 2017. Add this thread to a FAQ

  1. pateco


    Joined Aug 12, 2014
    2,004 posts, 521 likes
    Hunter 31 (1983)
    US Pompano Beach FL
    Last Wednesday, I got a temp alarm on our way out for evening races. I looked off the stern, and saw no water pumping. Shut down, and went below to check. Pump would spin, but no water. Luckily I keep a spare pump with fresh impeller in the parts box. I quickly changed out the pump, (just two 1/2" bolts) and was able to make it to the race start on time.

    This morning, I took the dead pump home and opened it
    . 2017-07-22 13.39.00.jpg
    Impeller was torn and all bunched up on one side.
    2017-07-22 13.45.11.jpg
    I was able to pry it out.
    2017-07-22 13.46.20.jpg
    But the central collar seems to be seized to the shaft.
    2017-07-22 13.50.53.jpg
    How can I remove this with out messing up the shaft or the bearing in the pump? Prying and needle nose pliers have not worked.

  2. kloudie1


    Joined Nov 6, 2006
    7,846 posts, 521 likes
    Hunter 34
    US Mandeville Louisiana
    One way to address would be to take off the circlip that holds the bearings in the housing.. Support the body on the mounting ears.. then tap the shaft out the (pulley) end using a large flat faced punch (or a bolt) that is slightly smaller than the ID of the impeller hub that is seized on. .. you'll want to have a new seal and bearings and impeller and gasket on hand .. then it'll be rebuilt and ready. attached is the pump drawing...
    If it is a 2 GMF the bearings are 6202.. if a 2GM (no heat exchanger) the bearings are 6200 on the original pumps. Read the numbers on the bearings to be sure.. they are inexpensive.. A good bearing supply plce should have them for 6-10$ each.. the seal should be about $6..

    Attached Files:

    Last edited: Jul 22, 2017
    Unwrittentimeline likes this.
  3. Tally Ho

    Tally Ho

    Joined Jan 7, 2011
    983 posts, 124 likes
    Oday 322
    US East Chicago, IN
    Penetrating oil would help, let it sit for a while. Then maybe some pointy locking pliers to get a good grip on what's left of the impeller.

    Be careful of prying against the pump body with a screw driver....don't ask me how I know


  4. pateco


    Joined Aug 12, 2014
    2,004 posts, 521 likes
    Hunter 31 (1983)
    US Pompano Beach FL
    PB blaster overnight worked. Thanks guys. New impeller should be here Tuesday.
    2017-07-22 14.11.39.jpg

  5. Ron20324


    Joined Jan 22, 2008
    6,102 posts, 539 likes
    Beneteau 323
    US Annapolis MD

  6. Lee Hadjiosif

    Lee Hadjiosif

    Joined Apr 14, 2010
    139 posts, 1 likes
    Beneteau 381
    US Herrington Harbour South
    You are very lucky that you carried a spare pump. Most of us carry spare impellers....

  7. Benny17441


    Joined May 24, 2004
    5,391 posts, 309 likes
    CC 30
    US South Florida
    Just a thought, when an impeller comes apart like that there is a fair chance that small pieces can work their way into the cooling passages of the exchanger and cause immediate or future blockages. Just inspect the torn impeller and gauge whether it is all there or there might be pieces missing and how large could they be.

    Don Crowther likes this.
  8. pateco


    Joined Aug 12, 2014
    2,004 posts, 521 likes
    Hunter 31 (1983)
    US Pompano Beach FL
    Fresh one in the replacement pump, and once this one rebuilt, I will have another spare. I guess I could order another impeller kit so I don't have to wait shipping time without a spare next time, But I have a good used one (still supple and no cracks) in the parts kit from my last annual replacement just for emergencies.

    I can give thanks to the previous owner for the spare pump. Trying to replace the Impeller at inopportune times can be a real pain.

    I did the impeller replacement the first time we had a failure by dropping sails and anchoring near the inlet to our home port and then trying not to lose any of the cover screws while bobbing around in seas and 100° Heat. Two weeks later I found the spare pump in one of the lockers in an unmarked cardboard box along with some spare V belts. The pump swap is much easier, and takes a lot less time than replacing the impeller. LOL

    This is a standard 2GM (Raw water cooled) so no exchanger to worry about. But from taking it apart, it looked to be all there Just destroyed.

    Last edited: Jul 24, 2017
  9. pateco


    Joined Aug 12, 2014
    2,004 posts, 521 likes
    Hunter 31 (1983)
    US Pompano Beach FL
    Any idea where to get a spare shaft or pulley? The shaft in the spare pump seems to be very slightly off at the end where it attaches to the pulley. Either that or the pulley is a little bent. It spins fine and doesn't vibrate, but it is enough off that I am worried about possible belt wear . Once the original is repaired this one will go back in the spares box, but having it perfect would ease my mind.

  10. Robert Knupp

    Robert Knupp

    Joined Jul 27, 2017
    1 posts, 1 likes
    Hunter 30T
    Un Ft. Myers Beach, Fl
    Just for reference, I recently had to replace the raw water pump on my 91' 2GM20f and found I could spend $200 less by ordering the Johnson pump vs the identical pump in a Yanmar package. The pump was identical in every respect and bolted on with no modifications. I figured it's worth sharing. Screenshot_20170727-175526.png

    pateco likes this.
  11. pateco


    Joined Aug 12, 2014
    2,004 posts, 521 likes
    Hunter 31 (1983)
    US Pompano Beach FL
    Water pump refurbishment completed. Going back on the boat tonight.
    2017-07-31 08.21.25.jpg 2017-07-31 08.21.51.jpg

  12. Mickstr


    Joined Jun 1, 2007
    138 posts, 13 likes
    O'Day 322
    US Mt.Sinai
    Where'd you have that price of $400+ ? I see Toad has it for $245. I think I'd like to get a spare myself..

  13. pateco


    Joined Aug 12, 2014
    2,004 posts, 521 likes
    Hunter 31 (1983)
    US Pompano Beach FL
    Two weekends ago, after I had just finished up doing a fuel filter change, and restarted the motor, I noticed I had no water flowing out my exhaust. I stopped the engine and spent 10 minutes swapping it out for my spare water pump. This solved the cooling issue, but left me with a pump to overhaul. When I took it apart, I noticed two issues, both requiring new parts.
    1. Impeller (only about 6 months old) lost a fin, and the fin had jammed itself into the water outlet.
    2. Jammed impeller somehow managed to strip the keyway cuts in my pump pulley, allowing it to spin under load.
    2018-06-10 11.49.04.jpg
    2018-06-10 11.49.12.jpg
    So I picked up a new impeller locally, and ordered the pulley from Toads. Got it put back together and it is now in the spares box.

    This is the second pulley that I have had to replace for this very reason, so now both of my pumps have brand new ones. Have any of you had similar issues with the pulleys?

    How long do your impellers last?

  14. Justin_NSA


    Joined Jul 7, 2004
    4,578 posts, 685 likes
    Hunter 30T
    US Cheney, KS
    FWIW. I installed a SpeedSeal Life a couple years ago. I think they re-named it to "Easy Slider'.
    The premise may be, if it's easier to replace the impeller, it will get done more often. Also nice in a failure if you don't have the proper tools handy.
    Not going to help if your shaft locks up.

  15. Sailm8


    Joined Feb 21, 2008
    1,487 posts, 162 likes
    Hunter 29.5
    US Punta Gorda
    You might consider replacing the shaft and bushing. Maybe some wobble might be jamming the shaft and damaging the pulley.

  16. pateco


    Joined Aug 12, 2014
    2,004 posts, 521 likes
    Hunter 31 (1983)
    US Pompano Beach FL
    If I replace the shaft, that means new bearings and seals as well. I found the shafts at Toads, and a Yanmar bearing and seal kit on E-bay. However I think I will wait and see how well the new pulley works on the spare pump I have installed now.

  17. HMT2


    Joined Mar 20, 2014
    550 posts, 119 likes
    Hunter 31
    US Shoreacres, TX

    I’ve had my boat almost eight years and have never had a single issue with my water pump, (saying this in writing could be the kiss of death to that good fortune) I have replaced the impeller maybe three or four times. But they were always in great shape. That you have had so many issues would make me think something is not quite right. Good luck!