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Gas Leak at brass fuel line connection

Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=51218
Printed Date: November-24-2024 at 1:54pm


Topic: Gas Leak at brass fuel line connection
Posted By: 91NaughtyQ
Subject: Gas Leak at brass fuel line connection
Date Posted: June-30-2023 at 8:33am
My 1991 Nautique (700 hrs) has developed a small gas leak at the bottom of the brass fuel line from the Diaphragm pump up to the carb.  It is leaking at the connection of the brass tube and elbow joint.

Line was replaced somewhere around the 400 hr mark.  

I checked the connection and it is tight.  Is there an O ring inside that connection that you know of that may need replacing or do you guys have a recommended solution other than a new line?

Thanks in advance. 

Gary


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1991 Ski Nautique
(Previous)1984 Ski Nautique 2001



Replies:
Posted By: KENO
Date Posted: June-30-2023 at 1:22pm
Here's a picture of what's at the fuel pump.

You have an inverted flare fitting and the fuel line is flared to match the fitting. When you tighten the nut, you're tightening the flare down against the inverted flare inside the fitting.

The seal is provided by metal to metal contact with the nut holding them tightly together, with no gaskets or sealant of any kind

Any leakage out the threads means the seal between the tubing flare and the inverted flare is bad

Trying to seal the threads isn't gonna fix the problem.

Replacing the line and the fitting together should fix the problem.

https://ibb.co/TtzSz9m" rel="nofollow">

The inverted flare fitting (your elbow joint) is called a "90 degree elbow inverted flare 3/8 tube X1/4 male pipe thread fitting"

Just to make finding one easier, here's a link to a bunch of different places Wink

http://www.google.com/search?q=90%C2%B0+Elbow+Inverted+Flare+3%2F8+Tube+x+1%2F4+Male+Pipe+Thread&sourceid=chrome&ie=UTF-8" rel="nofollow - link

The pipe threaded end that screws into the fuel pump can get sealed with gas resistant sealer, but like mentioned above, no sealer where the fuel line nut screws into the fitting




Posted By: 91NaughtyQ
Date Posted: June-30-2023 at 3:12pm
Appreciate the info as always.   For the record when I put it on a few years back I did not have flare wrenches -  I bought some today and was able to tighten it about 1/2 turn more.  I haven't started it and tested the joint yet but if it still leaks after that then replace it right?  If so have you used the flexible ones that Ski Dim builds or do you have an opinion on it?

Thanks as always!

Gary


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1991 Ski Nautique
(Previous)1984 Ski Nautique 2001


Posted By: KENO
Date Posted: June-30-2023 at 5:00pm
I was gonna say, grunt down on it a little more but you said it was tight. I guess it's a little tighter now.

Maybe that'll do it for you.

USCG approved rubber hose or metal, it's your choice.

Me...........I'm a rubber hose kinda guy, but everybody has their preferences Wink




Posted By: 75 Tique
Date Posted: June-30-2023 at 5:46pm
Sounds like someone is anxious to get out and do some skiing

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_____________
“So, how was your weekend?”
“Well, let me see…sun burn, stiff neck, screwed up back, assorted aches and pains….yup, my weekend was great, thanks for asking.”


Posted By: 91NaughtyQ
Date Posted: July-01-2023 at 5:12pm
Don't you know it sir.  After 3 yrs off skiing last weekend - you couldn't punch the grin off my face.  What's crazy is that you don't forget how to ski, you just lose some stamina behind the boat.  If you tell me to pick only one sport for the rest of my days skiing gets the nod.

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1991 Ski Nautique
(Previous)1984 Ski Nautique 2001


Posted By: 91NaughtyQ
Date Posted: July-01-2023 at 5:15pm
Originally posted by KENO KENO wrote:

I was gonna say, grunt down on it a little more but you said it was tight. I guess it's a little tighter now.

Maybe that'll do it for you.

USCG approved rubber hose or metal, it's your choice.

Me...........I'm a rubber hose kinda guy, but everybody has their preferences Wink



Well I thought it was tight however......  I picked up some line wrenches and I was able to go another 3/4 turn tight and all is good sir.  Also found I needed to snug up the 4 screws that hold the accelerator pump in place.  There was some surface fuel around the seal.  All in all no more leaky smelly gas.


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1991 Ski Nautique
(Previous)1984 Ski Nautique 2001


Posted By: 91NaughtyQ
Date Posted: July-10-2023 at 8:53am
KENO - 

Just a quick update.  It started to drip again, so I just went ahead and ordered the rubber line from Ski Dim which will be here today.  Appreciate the input.


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1991 Ski Nautique
(Previous)1984 Ski Nautique 2001



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