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Aft bilge pump lets water in?!

Discussion in 'Cabo Yacht' started by Jrms80, Nov 28, 2015.

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  1. RER

    RER Senior Member

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    Not sure where you get the idea that you are limiting how you operate your boat from his suggestion. It's prudent operating procedure to throttle down in a measured manner, rather than pulling the sticks back so fast that you are passed by your own wake.
  2. Jrms80

    Jrms80 Member

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  3. Jrms80

    Jrms80 Member

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    This is the affending hole. About 3 inches above the water line. It's about 1 inch diameter for scale.

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  4. Jrms80

    Jrms80 Member

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    This is inside the boat. It's a I inch diameter hose going to the fitting. There is no room for a loop. I could strap the hose maybe 2 inches higher but I doubt that would fix it.


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  5. Jrms80

    Jrms80 Member

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    You guys are killing me! First off it's a new to me boat so please take it easy on all the "corrosion" complaints. :) Give me a chance please! Also I don't think it's enjoyable boating to have to worry about water entry every time you come off/on plane or when high speed (8-10) knot trolling for wahoo, but hey that's just me, you know slamming the throttles back and forth to the stops, doesn't everyone operate that way? There is no way I'm screwing a rubber flap onto the side of the boat or drilling a new hole I'd rather it sink with me aboard AND all bilge and the crash pumps running! It's getting a check valve!
  6. Jrms80

    Jrms80 Member

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    It goes in tomorrow! Above the water line :)!

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  7. Capt J

    Capt J Senior Member

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    Perfect, the hose is most likely 99% sure a 1-1/8" hose as all Rule 2000 bilge pumps use that hose size. You'll be fine with the check valve, and it will solve your problem, and is much safer than a shutoff valve because when you're running all bilge water goes to the aft pump.
  8. Jrms80

    Jrms80 Member

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    By the way everyone posting here frequently tests all their bilge pumps as part of a regular maintenance plan, right? I'll do the same and with that in mind the odds are good the check valve will be operational if, when I ever really need it.

    All kidding aside thanks to all for a great exchange of ideas and boating knowledge.
  9. PacBlue

    PacBlue Senior Member

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    Sorry about the corrosion comment, I was gonna remove it and should have. It is a pretty tough crowd on this forum, but a small price to pay for a lot of real boater knowledge.

    Chopping throttles - love to whenever I can, especially coming back to harbor in glassy seas, late evening, it's just a personal thing!

    I always test new boats by chopping throttles at WOT, sea conditions allowing, to see how she glides and at what kind of attitude. Gives me some insight into hull design and efficiency.

    One last thing - the bilge pump exits out the side or at the aft end/transom? If it is out the side, kind of a different story!
  10. Jrms80

    Jrms80 Member

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    Your looking at the port side far aft. That's where the hole is. It's very close to the stern as you can see from the inside shot. The tube right below the bilge fixture is the engine exhaust tube that exits at the stern.
  11. PacBlue

    PacBlue Senior Member

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    Ahhhhh, no wonder, that explains a lot!

    Had a 45 Hatteras Convertible next to us that would have water blowing through its Head Sink Drain underway, the thru-hull was located on the side of the hull, they put an frp clam shell on it to make the problem go away.
    In your case, the blister at the forward side of the discharge is not protruding far enough out from the hull, so as you are underway at relative slow or not planning speeds, there is enough attachment of the water flowing on the side of the hull by the thru hull that it is feeding back through your bilge plumbing.

    So, back to a check-valve solution and/ or a larger blister/ clam shell.
  12. Trinimax

    Trinimax Senior Member

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    Now seeing that the discharge is on the hull side not on the transom. As PacBlue said a clam shell on the hull side should help to delfect the water while moving forward, and if done properly it will look alright and wont be very noticeable. The only issue with the clam shell is that it would direct water into the discharge when backing down aggressively, which should only be a relatively small percentage of the time
  13. Capt Maritime

    Capt Maritime Member

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    I noticed water in the aft bilge after a weekend cruise in the 40 Cabo. My boat has (2) rule pumps in the lazarette and I'm going to take a look when coming off plane when the waterline goes awash. Its possible this could be where the salt water is coming from. Those small in line check valves should do the trick.
  14. Capt Ralph

    Capt Ralph Senior Member

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    Are your discharge outlets on the transom?
    Tall hose loop over the discharge outlet?
    I would rather increase the height of the loop vs adding any obstruction to the discharge line.
  15. mapism

    mapism Senior Member

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    I also don't like non-return valves anywhere along the discharge lines of bilge pumps.
    They are OK for fresh (=clean) pressurized water circuit, but not for dirty bilge water.

    On top of raising the loop, you might also consider adding a small diaphragm pump for sucking the last small volume of water, which isn't enough for submersible pumps to work well.
  16. Pascal

    Pascal Senior Member

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    Check valves are bandaids on a lousy installation. Usually needed when the bilge area is too small to handle a long discharge hose flowing back. They should not be used to prevent water from coming in from the outside. All you need for this is to raise the loop above the discharge TH.
  17. Capt Maritime

    Capt Maritime Member

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    The bilge pumps do not discharge out the transom. They discharge out at the waterline forward of the cockpit.
  18. Capt Ralph

    Capt Ralph Senior Member

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    I'm sure the same responses (certainly mine), but your sure is water in from the pump outlets?

    Leaking rudder post, transom haws-pipes, previous trapped water, A C condensate, shower sump, bait spill over, any other thru hull fitting not in my mind leaking or,, OR,, Spilled Beer??

    How tall are those pump loops anyway??

    Can't be those fancy shaft logs. (??)
  19. mapism

    mapism Senior Member

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    CM mentioned salt water, so at least those two can be ruled out... As well as beer! :)
    Anyhow, I think his idea of keeping an eye on the boat sides while coming off plane is a good one, because potentially backpressure can overcome also a decent loop. Actually, I wouldn't expect a lot of backpressure (if any at all) forward of the cockpit, but you never know...
  20. Capt J

    Capt J Senior Member

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    If the discharge is under water, it needs an anti syphon valve. Even if the loop is high, it's possible for it to syphon back if the hose is long enough below the loop. Also if on the hull side and you're running there's a remote chance it could get pushed up in there.