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Topic: Pin hole Fuel line leak on U270 return diesel line (Read 366 times) previous topic - next topic

Pin hole Fuel line leak on U270 return diesel line

Lately I have noticed that the top of the U270 diesel fuel tank has diesel on it and a little bit dripped on the ground.  Investigating it turns out that the fuel line (presumably the return line) from the Cummins 8.3 is squirting a little diesel when the engine is running.  I am not sure if this is the return line but assume it is as it is under a little pressure and the engine runs fine on our latest trip.  The fuel lines were replaced by Cummings some years ago by the previous owner.



The hose is the forward most (right as you look at it on the pax side) fitting and has a threaded  fitting that goes into the top of the fuel tank.  The leak is right next to the fuel tank fitting on a steep bend in the braided hose. Ideally I would like to disconnect the hose and hopefully pull it back into the forward bay where I can cut it...add a compression fitting and extend it with a foot or so of new line it can be put back in place using another 90 deg compression fitting that will thread back in to the tank.  Or....if the tank must come out repair this leak with some kind of tape or JB weld until the full 150 gal tank is almost empty (like in a year I guess).  I might have enough room on top of the tank and under the floor to do this if there is a product that can seal the line for now.  Any advice appreciated.  There are no other leaks in the system.

Thanks
Carl
1997 U270 36' coach
Carl and Kathleen
Killeen Texas
1997 U270

Re: Pin hole Fuel line leak on U270 return diesel line

Reply #1 –
Carl,

As was recently discussed in another thread, do NOT allow diesel onto the FG floor of that compartment.  It will find its way into the basement box beam structure where it will DISSOLVE the foam insulation in the floor structure.  It can deform the basement structure and is close to impossible to get the diesel fuel smell out without major "surgery".
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Pin hole Fuel line leak on U270 return diesel line

Reply #2 –
You should be able to fix it without pulling the tank. There might be enough hose
so you may be able to just cut the hose and push the hose back on the fitting.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Pin hole Fuel line leak on U270 return diesel line

Reply #3 –
Quote from: Carl Cox –
1. I am not sure if this is the return line but assume it is as it is under a little pressure and the engine runs fine on our latest trip.
 2. The fuel lines were replaced by Cummings some years ago by the previous owner.
 3. The leak is right next to the fuel tank fitting on a steep bend in the braided hose.
4. Ideally I would like to disconnect the hose and hopefully pull it back into the forward bay where I can cut it...
5. add a compression fitting
6. extend it with a foot or so of new line it can be put back in place using another 90 deg compression fitting that will thread back in to the tank.

Carl,
1. On your coach that is the return line
2. I pulled the pic. up on a big monitor and those lines appear to have the FT hose ID stickers on them. Whether they have or have not been replaced you need to get that leak fixed before you have a bigger problem.
3. Normal spot for the leak, it could be split at the fitting and running down the hose.
4. That has worked before
5. The fittings are push lock not compression
6. This will work for a while as I have had to do the same for a friend till they could get back to home base.
6a. You can reuse the OEM tank fitting if you are careful to remove the old hose not scratching the barb end.

The trouble you will have will be the splice to the old hose. You will find the old hose stiff and not pliable due to age and heat cycles. If you are lucky you can get a push lock splice to slide in the old hose if you warm it with a hair dryer. You should be able to do this patch without pulling the tank.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."
 

Re: Pin hole Fuel line leak on U270 return diesel line

Reply #4 –
Does the red arrow point to the spot of the leak? If so, I would do as Peter (oldguy) says in his above post. To loosen, buy a Crow's Foot and use a 3/8" and extension with ratchet to loosen and then tighten the fitting. I use Crow's feet when workiing on fuel and hydraulic lines where I can't be at a right angle to the fittings.

Pittsburgh 3/8 Crowfoot Wrench Set - Google Search

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)