Re: Bow thruster oil seal leak



You have a number of problems, some I can help you with. 

  1. You should never put 100% trust in inherited parts unless you are absolutely sure of their origin. 
  2. You should always buy critical parts from Amel and Amel only.
  3. We all should support Amel SAV because we need them
  4. The Amel OEM part does not have a double lip
  5. The original Amel OEM seal was for a 30 x 42 x 8 single lip seal, but Amel changed that spec to 29 x 42 x 8 single lip seal
  6. Your seal is the wrong size
  7. I do not see any RTV sealing the seal to the seal seat. 
  8. Failure to seal the edges with RTV will likely cause a leak
  9. If the correct seal is used, it should be recessed to the casing about 2-3mm. 
  10. Failure to press the seal all the way in will likely cause a leak
It is possible that the propeller shaft is worn and needs replacing. I believe Amel has these in stock. I have seen worn shafts repaired with a stainless steel sleeve and work correctly, but I think by the time you pay to have this done, a replacement shaft is a better and cheaper solution.

It is also possible that the seal seat (the recessed area where the seal is pressed into) is damaged, or was not clean when you pressed the new seal in place..

CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
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On Sun, Mar 15, 2020 at 12:08 PM Peter de Groot <pandmdegroot@...> wrote:

Greetings all,
This is the second lip seal I've installed.  (The previous owner left a handy stash of parts on board) The first had a single lip, the second came in a bag with Paulstra brand and part number 792521 IEL 30 42 7.  I'm deducing it came from Amel.  It had two lips, a heavier one inwards to retain the oil and a lighter one outwards nearer the outside surface.
Regardless they both leaked after installing.
The surface of the shaft which is not SS (FRP maybe??) feels rough, and there was only a narrow band where it feels smoother.  
The oil that came out was cloudy green, thick like a milk shake, so I'm thinking water was entering.
The question is what to do.  I'm contemplating 3 choices:
-Purchase a new shaft from Amel, perhaps a new complete bow thruster, as the counterbore to receive the seal also has some chips.
-Find a SS speedi-sleeve to provide a smoother surface, machine existing shaft if necessary.
-Make a new shaft with a local machine shop.  In which case which material?  Acetal perhaps, I'm assuming stainless is a no-go.

I'd appreciate any advice if any of you have experienced the same problem.  

Peter de Groot
SM 207 la Querida
Moss Landing, California.

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