[C320-list] Yanmar 3YM30 - Leaking hose barb

[Jeff Hare]

Double check that it isn't the radiator cap. Replaced mine this year because it was leaking out the top around the center rivet. 

-Jeff
-----Original Message-----
From: Robert Seastream <robert.seastream at comcast.net>
Sender: c320-list-bounces at lists.catalina320.com
Date: Sat, 3 Jul 2010 07:57:43 
To: <C320-List at Catalina320.com>
Reply-To: C320-List at Catalina320.com
Subject: Re: [C320-list] Yanmar 3YM30 - Leaking hose barb

I've got a coolant 'mystery leak' that appears to be coming from the  
heat exchanger end cap and drips onto the main fuel line that runs to  
the injector pump.
That end cap has to come off and be regasketed or resealed, but that's  
a fall project.  I think the reason I never see it is because it  
evaporates on the hot engine.

Bob Seastream
Intuition # 906

On Jul 2, 2010, at 10:02 PM, Allan S. Field wrote:

> Brad - I can't help you with the 3YM30m but...on my previous boat, the
> alternator wore a hole through the hose.  I was sailing on the  
> Patapsco in
> March, a friend went down below, and coming back up, asked if 4  
> inches of
> water sloshing around over the floor boards was normal.   
> Fortunately, it
> only took me about 10-15 minutes to figure out where my leak was  
> coming from
> and get it fixed.  And fortunately, I was not singlehanded that day  
> and had
> a friend who went down below and discovered the water.  The point is  
> that
> you need to get the hose away from the alternator immediately and  
> replace
> any hose with wear patterns.    But was that water ever cold... -  
> Allan
> 	
> -----Original Message-----
> From: c320-list-bounces at lists.catalina320.com
> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Brad  
> Kuether
> Sent: Friday, July 02, 2010 9:51 PM
> To: C320-List at Catalina320.com
> Subject: [C320-list] Yanmar 3YM30 - Leaking hose barb
>
> Hey everyone,
>
> Well I tracked down the mysterious leak of anti freeze and have  
> traced it to
> the hose barb that supplies the hot water heater, (Or possibly  
> returns it).
> It will need to be removed and rebedded.
>
> Some things that I found somewhat concerning on this 2004 boat with a
> 3YM30....:
>
>  a.. The hose barb had tons of threads exposed.  Maybe not the right  
> size?
>  b.. The "paste" used to seal the barb was very soft and almost melted
> after the engine was hot.  My neighbor indicated that it "wasn't the  
> right
> stuff" for that application.
>  c.. The hose that connects to the hose barb is run over the  
> alternator.
> It is wearing through the hose.
>  d.. The return is a long bronze tube the sticks way out of the  
> engine to
> pick up the return hose.
>  e.. The return hose is run "behind" the alternator, and shows  
> significant
> wear.
>  f.. Overall this doesn't feel "right" for a 2004 boat with 204 hours
> total.  It almost feels like the water heater was a "second thought"  
> and was
> installed by a car mechanic.
> Has anyone else seen this type of hot water heater hose installation  
> on
> their 3YM30s?
>
> Has anyone seen some of the same symptoms?
>
> Has anyone changed it around so the hoses are less suseptable wear?
>
> Has anyone re-run new hot water heater hoses, and about how long did  
> it take
> and what might I watch out for?
>
> ANY advise appreciated.
>
> What a bummer and I was in such a sailing groove as of late.
>
> -Brad, Mary, Monica, and Jarod
> "Independence"
> 2004 Catalina 320 Hull 1006
> Middle River, MD
>