www.iFourWinns.com

I had a low water pressure issue when on muffs and fried an impeller -- after I replaced the impeller I also found the small plastic tubes which fit into the brass pump are leaking. (no other engine issues are we were out this weekend and temps were normal with my spare older impeller)

Anyone had these plastic tubes leak?

Any fixes?

While I might tolerate some drips in fresh water, you don't want to do that for a long time in salt water, which is where I boat.

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DaleG -- West Palm Beach FL
2003 240Horizon -- 5.7Gi -Duoprop

I've never had mine leak. Each time I change the impeller I wonder about how those plastic pipes are sealed into the pump body, I'm sure they can't be just a press fit ( as plastics creep under stress and would eventually come loose).

Are your's actually loose? If it's heat that has loosened them/ the sealant, further heat from a hot air gun might be enough to loosen them up and remove them. The sealant can't be a polyurethane, as the temperatures you could have reached would not soften them. Possibly an epoxy. Maybe a moisture cure PU like 5200 could be used to seal/ bond the tubes back in.

If you can't get them out, from memory there is a section of the tubes beyond the hose stop lugs . After suitable abrasion, 5200 could be used to bond/ seal the outside of the tubes there to the pump body.

Graham

What plastic tubes are we talking about?

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

Mine are loose and will rotate -- not freely -- but fairly easily -- I am guessing the heat loosened whatever held them in ---If I don't find a better solution I think I will try something like 5200 first before I buy a new housing -- I need to put a good impeller in and pull the old spare used one out anyway ---

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DaleG -- West Palm Beach FL
2003 240Horizon -- 5.7Gi -Duoprop

Mike -- when you attach your hoses to your sea water pump driven from the crankshaft -- you are actually attaching the hoses to plastic tubes that seem to be pressed into the pump housing. It is not actually metal there.

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DaleG -- West Palm Beach FL
2003 240Horizon -- 5.7Gi -Duoprop

Hell's bells I didn't know that. I think if those came loose I'd be looking to replace the pump.

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

I may infact have to replace the pump housing --

The lines on the areas the hose attach are where the tubes are -- my leaks are at those lines.

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DaleG -- West Palm Beach FL
2003 240Horizon -- 5.7Gi -Duoprop

Is it possible that he "tubes" have been cracked as a result of overtightening? Have you checked them carefully? I'd think that would cause leakage.

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Paul
2007 Four Winns Horizon 220
Mercruiser 350 Mag MPI w/ Bravo III Drive
2004 Ford Explorer Limited (V8-AWD)
Pomme de Terre Lake (Southwest Missouri)

I've never taken those hoses off, and am amazed those are plastic. It's good to know this. Still, I have to think there was some sort of defect or like Paul said, overtightening or something that caused this. I can't think of any way to repair that, that I'd consider acceptable given the risk of one of them letting go while under way. One side is under suction so it probably wouldn't ever come apart, but the other side is under pressure...

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

Guess it can't hurt to try - what is the worst that can happen - you would have to replace the pump. At least you have the time to look around for a deal.

I would think the worst would be the pressure side coming apart during a WOT run and the engine & manifolds going a few moments without water before the computer shuts it down.

It would be nice to know how this happened.

Wonder if it would be possible to replace the plastic tubes with brass nipples, soldered into the housing? Just brainstorming.

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Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

Here is the situation -- the tubes are a press fit, but may have some unseen tab or something which also holds them in
(they do not screw in or out)

When I ran the engine with low water pressure the pump overheated enough to loose about four vanes on the impeller and cause some smoke and discoloraiton on the pump. I believe this overheating caused the plastic to melt slightly (temporarily) and loosen. They can now be rotated fairly easily by hand, but I cannot get them out.

If I could actually get them out I would coat them with a sealant and reinstall them.
(I happen to be a plastics engineer among other things)

I would think this is rare --- and I doubt they will ever come out on anyone.
I did think however that someone else could have a had a leak there and either somehow got them out -- or had a neat fix with some sealant to fix the leak -- the leak is just a small but constant drip.

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DaleG -- West Palm Beach FL
2003 240Horizon -- 5.7Gi -Duoprop

Dale,

I am also involved in plastics, I can't believe it can just be a press fit of the plastic stubs into the bronze housing, even if they have glass or mineral reinforcement. Creep would be too much of a potential issue. ( if they are just a press fit, maybe we can get jobs at VP to advise them on materials engineering; Sweden is a nice place in the Summer! ). If the stubs are not a polyolefine, then a single pack PU product like 5200 would bond extremely well. Even better would be a 2 component PU adhesive ( Ford used to use such adhesives to bond spoilers to trunk lids, they would never ever come off without taking the paint with them).

Graham

Dale,

I replied to your PM, but it sits resoulutely in my "outbox" and refuses to be sent no matter what I do; The Polyurethane industry is the answer to the question you asked !

Graham

Were you able to get this fixed or have to replace?