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raw water pump replacement

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    raw water pump replacement

    I'm wanting to replace a leaky raw water pump on my '90 150 Hino and hoping to get some tips here. I've done searches but cant seem to find anything on the subject other than impellor replacement. I have a new pump. Old pump has been leaking salt water and bolts appear rusty so I am concerned about breaking head off bolt. Thanks for any and all info and tips
    Maple Bay Yacht Club
    1990 3288 "Allure" w/150 hino x 2
    2004 Campion 622 fish killing machine "Knucklebuster", 150 yammy 4 stroke

    Lots of penetrating liquid (brand of your choice) and time. Especially the time. Run the engine to operating temp and apply the PO. Let it sit for a day. Repeat. After repeating on the third day, try to see if it budgets at all without reaching the "snap it off" kind of torque. If one or all don't want to budge, you may need to continue the process until they do.

    While working on an auto engine, we ultimately had to drill the heads off to ensure we had the remainder of the bolts, pulled the pump then had access to where the threads entered the block. More heat (this time with a torch) and penetrating oil. Repeated on day 2 and locked some vice grips on the bolts and they spun right out.

    Best of luck.

    Edit: After second read, your pump may not be attached to the block? If so, running the engine won't help. Just use a small tipped torch to heat the bolt head (and thus the bolt). Same principle. Time. Might have to do it several time to get the PO to wick into the threads.
    1998 BL Ciera 2655 Sunbridge LX (Special Edition)
    "Sea Flights"
    5.7L 2bbl w/Thunderbolt Ignition and raw water cooling
    A​​​​​​lpha I Gen II Sterndrive/1.45:1 gears
    M15.25 X 15P Black Max prop
    MFG Extra's - A/C, Fresh Water Engine Flush port, HWH and Windlass
    Docks @ Punta Gorda, Florida


      Be careful- OEM bolts are brass so won't respond well to heat
      1988- 3288, 1994- 3288, now Soul Asset: 2001- 3788 w/330s


      • pgiconch
        pgiconch commented
        Editing a comment
        True. Im not familiar with the Hino, so didnt realize they are brass. Does complicate it. Perhaps he can get a small flame to heat the area around the bolt seats so the PO can seep in. Noy many options if they are welded in by corrosion.

      Some good advice above! When I have had to drill off bolt heads, I’ve used ccw hardened drill bits. They provide bit of torque to help unscrew. Used in conjunction with heat, penetrating oil and time has worked pretty well.
      2000 4788 w Cummins 370's, underhulls, swim step hull extension
      12' Rendova center console with 40HP Yamaha
      MV Kia Orana
      Currently Alameda CA