Yanmar 3JH3E Cooling Hoses

Gary Ryan

Gary Ryan

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Sep 11, 2019
168
Hunter 386 Lake St. Clair
As I slowly replace parts on our Hunter 386 sailboat, I was thinking of tackling the water/coolant lines on our Yanmar engine. Is it worth purchasing off the shelf hose ( if so where) and trying to bend it or should I replace with original Yanmar hose? Thanks in advance,
 
D

dlochner

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Jan 11, 2014
12,325
Sabre 362 113 Fair Haven, NY
Depends which lines. The long hoses from the engine to the HW tank, it is not necessary to buy the Yanmar hoses, same with intake hoses from the sea strainer to pump. The other short formed hoses, buy the Yanmar hoses. And if you replace the fuel return hoses, buy the Yanmar hoses, standard ¼" fuel hoses don't quit fit and will leak.

I buy my Yanmar parts from Niemiec Marine, good prices and good service.

 
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Ralph Johnstone

Ralph Johnstone

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Jan 4, 2006
7,034
Hunter 310 West Vancouver, B.C.
Ensure hoses which are subject to suction are wire wound so they stay round. Ensure hoses to and from the HW tank are wire wound to allow them to go around tight corners without collapsing. Ensure there is a defibrillator nearby when you see the price of this stuff :yikes: .

Most hoses that fit up against the body of the engine are preformed and hence purchased from Yanmar. Ensure you have two defibrillators nearby when you see the price of these little buggers :

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Long hoses to and from other equipment are not Yanmar parts according to the Yanmar parts catalogues. The bulk 1/4" certified marine fuel hoses are a little snug on the existing fittings but can be stretched with a hair dryer. Lubricate all fuel hoses with Superlube to get them on and off in the future. Same applies to other hoses which are a tight fit.

I spent last winter replacing every rubber hose within the engine compartmnet.
 
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Gary Ryan

Gary Ryan

.
Sep 11, 2019
168
Hunter 386 Lake St. Clair
Thanks Ralph. In light of me having to remove the transmission to send in for a refurb, I think I'll put the hoses off until next year. And you're correct on the prices. Ouch. A little excessive for rubber. Plan on changing out the coolant and thermostat. I think I'll drain the coolant from system, remove thermostat, then fill with Distilled water a few times and flush. That should be good. Then put in new thermostat and coolant. Hoping not to get any air locks.
 
Scott T-Bird

Scott T-Bird

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Oct 26, 2008
6,216
Catalina 320 Barnegat, NJ
I agree with comments above. The preformed hoses need to be replaced in kind if you want to make everything fit together properly. Just don't do what I did ... the night before launch I needed to add coolant and oil, so I opened the coolant fill and absentmindedly added more than 2 quarts of oil. Boy, I was thinking, it sure is taking lots of oil! :facepalm: Uggh, what a mess! I blamed it on the pre-launch jitters!

IMG_6027.jpg
 
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Ralph Johnstone

Ralph Johnstone

.
Jan 4, 2006
7,034
Hunter 310 West Vancouver, B.C.
Gary Ryan said:
Hoping not to get any air locks.
Click to expand
Does your 3JH3E have an air release fitting as does the 2GM20F ?

1693498417067.png


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As I'm adding AF, the vent is open and a continuous hiss of air can be heard as the AF level rises. When liquid escapes the vent, the system is 100% full and no blocking bubbles in the system.
 
Ralph Johnstone

Ralph Johnstone

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Jan 4, 2006
7,034
Hunter 310 West Vancouver, B.C.
Scott T-Bird said:
the night before launch I needed to add coolant and oil, so I opened the coolant fill and absentmindedly added more than 2 quarts of oil. Boy, I was thinking, it sure is taking lots of oil!
Click to expand
Picky, picky, picky. Just small details :yikes: !

Don't know how your AF refilling goes on your 3GM30F re bubbles in the cooling system, but I see you don't have an air release fitting. My vent was originally (from the factory) installed much lower near the floor and I had a hell of a time with overheating each time I changed the AF. I moved it higher up (see post #8) and have never had an overheating problem since.
 
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Scott T-Bird

Scott T-Bird

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Oct 26, 2008
6,216
Catalina 320 Barnegat, NJ
I'm due for changing the coolant (probably end of season). I've never experienced a problem with overheating (other than when the water pump belt broke soon after I brought the boat home 3 years ago). I'll investigate. Not much use this year due to heart attack early in July. I'm just getting back to the boat more frequently now.
 
Gary Ryan

Gary Ryan

.
Sep 11, 2019
168
Hunter 386 Lake St. Clair
I have 3 bleeder lines to drain the AF. Maybe I'll video this when I do it. Then I don't have to remember next time :)
Ralph Johnstone said:
Does your 3JH3E have an air release fitting as does the 2GM20F ?

View attachment 219445

View attachment 219446

As I'm adding AF, the vent is open and a continuous hiss of air can be heard as the AF level rises. When liquid escapes the vent, the system is 100% full and no blocking bubbles in the system.
Click to expand
I like that idea. Not sure if we have one though. I could install.
 
Gary Ryan

Gary Ryan

.
Sep 11, 2019
168
Hunter 386 Lake St. Clair
Gary Ryan said:
I have 3 bleeder lines to drain the AF. Maybe I'll video this when I do it. Then I don't have to remember next time :)

I like that idea. Not sure if we have one though. I could install.
Click to expand
Reviewing your attachment, it looks like your bleeder is for the Sea Water hose?
 
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