For the 4-108, Sherwood vs Jabsco raw water pumps

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  • #6871
    Moderator
    Keymaster

    Our 4-108 has the Sherwood G65 raw water pump. It’s cover is showing serious signs of wear, so I assume it’s probably time to do a major rebuild – just to be on the safe side since we sail in some pretty remote places (Central BC coast in Canada).

    I am considering buying a new pump as a replacement, and rebuilding the original Sherwood to have as a spare.

    Problem is, the Sherwood G65 pumps are quite dear – and the order of $500 from US suppliers. Jabsco seems to make a less costly suitable replacement, PN 13929, but it’s 3/4 inch ports point upwards rather than sideways like the Sherwood does. We are far from our boat now, so I am uncertain whether there is room to replumb as required to use the Jabsco.

    Does anyone have any comments about Jabsco vs Sherwood raw water pumps?

    What about how hard it is to rebuild the Sherwood?

    As an aside, I talked with SpeedSeal, and they no longer provide their SpeedSeal covers for the Sherwood G65. The rep suggested they might have one to fit the Jabsco model, but when I asked which Jabsco model works on the 4-108, he told me to talk to a Perkins rep.

    Marilyn, Rainshadow

    #14831
    John Arthur
    Participant

    My Perkins 4108 has the Jabsco pump with the ports lying horizontally. I would have thought that the pump can be mounted whichever way you want as it self primes. As for the Speedseal kit the key part of the kit is the hand tighten screws so buying them at $10 a pair (spares) might be a way forward, albeit expensive, as I have not been able to find a six screw version from Speedseal.
    Regards, John.

    #14841
    Moderator
    Keymaster

    Thanks John – would you happen to know the Part Number of your Jabsco pump?

    The Jabsco pump I found listed for the 4-108 has two ports that point in the same direction. They could point in opposite directions if there is room around the pump to thread 90 degree elbows into the pumps ports and then plumb from there.

    Does your pump look something like this one?

    marilyn

    #14861
    Moderator
    Keymaster

    Arild kindly sent me a photo of his engine room showing how the jabsco pump fits nicely – how tidy his engine room is!

    I am curious though, where is the heat exchanger in this photo? Our forward small engine hatch exposes the top of the heat exchanger with the raw water pump barely visible underneath. This cramped quarters for the pump also makes the idea of replacing it seem more daunting.

    (I searched for a photo to show our engine arrangement, but oddly we don’t seem to have one…)

    Marilyn

    #14871
    John Arthur
    Participant

    Hi Marilyn. In answer to your link to the pump, yes that is it. The engine in the picture is the same as mine. The heat exchanger is part of the exhaust manifold. The grey coloured disc with lugs at the front of the long blue rectangle is the filler cap for the fresh water cooling. Inside that rectangle is the tube stack that is the heat exchanger. It sounds as though you have a remote heat exchanger mounted at the front of the engine. That being so, you may be able to mount it elsewhere to ease access to the pump.
    Regards, John.

    #14881
    Moderator
    Keymaster

    Thanks John – silly me for not noticing the heat exchanger at the exhaust manifold. I’m just used to seeing the exhaust manifold there so didn’t focus on the obvious filler cap!

    John also sent me a photo to post of a engine with the heater exchanger mounted at the front of the engine over the raw water pump. This is the configuration of our Perkins, but this does not look like a nic 38 engine room.

    (fyi, if you want to know how to post photos, see here and read the SECOND response to understand how to add photos to a reply

    Along with the photo, he said this in the email – I hope you don’t mind me quoting you, John:

    Quote:
    I have read in the manual that it is very important to align the pump to the drive component so it is probably not a quick exchange. I spent many years as a vehicle machanic and am firmly of the belief that if it ain’t broke don’t fix it. Wear on the cover plate would have to be VERY severe before I would consider changing even that! I hope this helps in your endeavers.
    Regards, John.

    I think we’ll just replace the badly worn cover and once we need to replace our heat exchanger, we’ll add a hot water tank/heat exchanger combo – which means we could get better access to the raw water pump for repairs and be able to get rid of the Valient instant on water heater in the galley (which I do like but I’m not keen on the propane risks.)

    Marilyn
    8dc2q-forward-header-tank.jpg

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