Fuel leak

Topic: Fuel leak (Read 1227 times) previous topic - next topic

Fuel leak

December 31, 2022, 03:26:57 pm

For a while I've been able to smell diesel, mainly in the bathroom area of my coach, usually after sitting for the night. My wife can't smell it, nor did my parents when they stayed in the coach last week. I figured maybe I was just smelling things. Last weekend I filled the coach with the decent prices right now, before the Quartzsite trip. After that fill, I could smell a stronger odor and Wednesday night saw two drips on the concrete below the curb side bay.

Investigating today, I find the top of the tank is damp with fuel, from the side inwards to almost the frame rails. It seems to be going from outside in, rather than inside out. None of the lines are damp. I don't see any leakage. Could this just be fuel getting past the fittings at the end of the tank and sloshing now that the tank is full? I'm guessing it must also be running down the front side of the tank as I believe that's where the fuel on the tank bolts that go through the basement, is coming from. There is also fuel residue on the LPG tank bolts, which is forward of the fuel tank...so I'm thinking this fuel is running along the foam and getting to those holes too.

What would be involved with removing those fittings at the end of the tank and resealing them? I assume there is some kind of tube on them, inside the tank?

Re: Fuel leak

Reply #1 – December 31, 2022, 03:29:03 pm

Keith,

This needs to be addressed right away (at least stopping the diesel from getting into the basement structure).

Diesel will DISSOLVE the insulation.

Re: Fuel leak

Reply #2 – December 31, 2022, 03:45:49 pm

Tighten the fittings that thread into the tank and also the line fittings. If that doesn't stop it and you don't have time before leaving on the trip to dive deeper then don't fill the tank but 3/4 full. wrap a clean dry cloth around each fitting so the fuel leaves a track to test while driving.

Re: Fuel leak

Reply #3 – December 31, 2022, 04:04:03 pm

Kieth it looks like you have the original lines? Very likely your leak is from them. I definitely think keeping fuel at a lower level at the very minimum will help/ wont hurt. Generally the leak is a air leak into the lines. Using a tissue you should be able to determine were the leak is coming from. If its dripping from the mount bolts the damage has been done. On my coach I discovered similar when changing fuel lines. Used barrier tape everywhere to prevent future damage and mine being quite old and dried out used spray foam to refill affected area as best as possible. Get ahead of this as quickly as possible. Once you have the void it can collect water and corrode structure.
Scott

Re: Fuel leak

Reply #4 – December 31, 2022, 04:06:40 pm

In my 1997 the fill cap would leak when I filled the tank by leaning the coach to get every last drop in. Never saw the problem unit I did one of those fill up right before letting coach sit for a few days.

On my 2014 there are extensions that goes from the tank to the outside fill. I guess I forgot about what happened to me before and did the same think with this coach. Diesel seeped through the pipe fittings.

Keith, your lucky your wife can not smell anything. My wife smells and hears everything!

Re: Fuel leak

Reply #5 – December 31, 2022, 04:25:01 pm

This is the first I've seen evidence of the fuel, so yes, I'm on it as quick as I can. I suppose the diesel may eat the insulation but protect from rust (haha). Is there anything I can spray in there to clean up and dissipate the diesel so it stops eating the insulation at this point?

I'll clean everything up, snug the fittings and wrap them as well.

Scott, I have no idea if they are original or not. What I can see looks to be in good shape. I can't see any cracks or leaking. The fact that the damp area only extends about 2-3 foot inwards makes me think I must be able to see where the problem is...just need to find it.

I do have non-vented, locking fuel caps that I added about a year ago. I don't see any residue down the side of the tank that faces out, below the fill neck, and I don't lean the coach to top it off. I usually just go to when the fuel is at the bottom of the neck on the inside.

Re: Fuel leak

Reply #6 – December 31, 2022, 04:35:45 pm

Looks to be the fitting nearest to the fill cap, looks like tracks of fuel under that fitting.

Re: Fuel leak

Reply #7 – December 31, 2022, 05:22:29 pm

You may be right Dub. All of the angled fittings into the tank were tight. I was able to get a full turn on that JIC fitting on the left, closest to the fill neck. I got about 1/2 turn on the middle fitting and maybe 1/4 on the big one.

The aluminum fitting on top with the 5/16" line going to it was loose. I was able to move it by hand, and got 1/4 turn on it to snug it up. Turning it makes the line a bit tight, so I'm thinking having no strain relief could have caused that. I'm going to get another piece of 5/16" hose and a union and add to that hoses' length so it's not pulling on the fitting to loosen it. I'll also safety wire that fitting to the one on the angled part of the tank so it can't loosen up.

I've cleaned it all with brake cleaner and should be able to easily spot any new fuel. I hope that's all it was.

Will simple green or another degreaser hurt the insulation? What about hosing down the front/back of the tank and the bottom of the bay with simple green and letting that displace the diesel?

Re: Fuel leak

Reply #8 – December 31, 2022, 05:49:55 pm

That small of a leak shouldn't have been enough to cause you any basement issues. A long period of time yes, but you already know this is relatively new. I wouldn't worry about it assuming it's stopped now.

Re: Fuel leak

Reply #9 – December 31, 2022, 06:01:40 pm

I would clean up what I could see and reach and go to Arizona. A man can't help what he can't see or reach. See you in Quartzite.

Re: Fuel leak

Reply #10 – December 31, 2022, 06:20:08 pm

Anything petroleum base is potential of being bad

Re: Fuel leak

Reply #11 – December 31, 2022, 07:25:56 pm

I would wager more fuel is spilled in that area filling up than what Keith has leaked. Not minimizing the importance of keeping that dry but fueling every other day odds are against at least a little not running down the tank.

Re: Fuel leak

Reply #12 – December 31, 2022, 07:58:56 pm

Keith I was admiring how different your floor vents are next to the tank mount. Much nicer than mine i think. Also would exit better if overfueled.👍👍

Re: Fuel leak

Reply #13 – December 31, 2022, 08:58:03 pm

Quote from: dsd – December 31, 2022, 07:58:56 pm

Keith I was admiring how different your floor vents are next to the tank mount. Much nicer than mine i think.

What do yours look like?

Re: Fuel leak

Reply #14 – January 02, 2023, 05:03:31 pm

Quote from: WS6_Keith – December 31, 2022, 08:58:03 pm

What do yours look like?

Poor picture but similar

Re: Fuel leak

Reply #15 – January 09, 2023, 04:12:06 pm

How many connections are there to the fuel tank? On the curb side, I see the 3 connections in my pictures above, plus one on the top of the tank behind the largest line. It's a 5/16" line, so I'm guessing it's a return from the generator or AH.

Looking across the tank (I have not yet removed the fiberglass panel on the street side), I can see another large hose at the other end of the tank. Are there two engine feeds?

I'm guessing the lines on this end are engine feed (largest line), AH feed and generator feed, with one return in the top.

Re: Fuel leak

Reply #16 – January 09, 2023, 05:11:35 pm

Keith,

You should have 7 lines in the top of the tank
Engine feed and return
Generator feed and return
A/H feed and return
Vent line.
Engine and generator come off about the center of the tank

Mike

Re: Fuel leak

Reply #17 – January 11, 2023, 07:33:40 pm

I have noticed on the newer coaches like 03 that there are 3 lines on each side. There should be numbers on the lines. I don't have a diagram from Foretravel, but you should be able to find the numbers on the other end of the lines. I am pretty sure the engine supply is 5/8, return line 1/2, and then the generator and aqua hot are each 3/8.

Re: Fuel leak

Reply #18 – January 11, 2023, 07:37:40 pm

Thanks for the info Ron. I'm going to pull the fiberglass cover on the other side this weekend and check those fittings. I've looked across the top of the tank and there is nothing in the center that I can see, but I can see another large hose on the street side, around the same area of the tank as the larger one in the pictures I posted. I'll know more Saturday.

Re: Fuel leak

Reply #19 – January 11, 2023, 07:41:51 pm

Thanks, let us know what you find.

Re: Fuel leak

Reply #20 – January 12, 2023, 01:28:16 pm

Quote from: red tractor – January 11, 2023, 07:33:40 pm

I have noticed on the newer coaches like 03 that there are 3 lines on each side. There should be numbers on the lines. I don't have a diagram from Foretravel, but you should be able to find the numbers on the other end of the lines. I am pretty sure the engine supply is 5/8, return line 1/2, and then the generator and aqua hot are each 3/8.

My 96 U320's AquaHot fuel lines are 1/4 inch.

Re: Fuel leak

Reply #21 – January 12, 2023, 05:58:24 pm

Quote from: dsd – December 31, 2022, 04:04:03 pm

Kieth it looks like you have the original lines? Very likely your leak is from them.

This would probably be the first 2003 to have an issue with fuel lines (if that's the problem). The 1990's and up through 2001 were seeing cracks, but I don't ever recall a 2002 or newer having the same issue.

Re: Fuel leak

Reply #22 – January 12, 2023, 06:03:23 pm

Quote from: Michelle – January 12, 2023, 05:58:24 pm

This would probably be the first 2003 to have an issue with fuel lines (if that's the problem). The 1990's and up through 2001 were seeing cracks, but I don't ever recall a 2002 or newer having the same issue.

I'm confident the issue is not with the lines, but rather with the fittings. I had to tighten one a full turn, another 1/2 a turn. The fitting on top with the 5/16" line going to it, presumably the vent, was also loose to the tank. I'll be checking them all on both sides this weekend and safety wiring the top fitting to the side fitting so it cannot loosen up.

Re: Fuel leak

Reply #23 – January 14, 2023, 03:10:22 pm

Today I got into the street side of the fuel tank to check for leaks. Man, they didn't leave any room to remove the fiberglass panel, so the best I could do was pull it outward and shove my hand (and phone camera) back behind it to check for fuel and see if the fittings were tight. All were tight and there is no fuel residue on this side. There are 3 more fittings, like on the other side, but no top mounted vent on this side.

On the curb side, I tightened the top mounted vent fitting and safety wired it to one of the side fittings, so it cannot loosen up again. Since I've turned the fitting over 90* from it's original location, the nipple now faces in the wrong direction. I found this hose called "sidewinder" on Amazon. It's got several different bends in it and you can just cut off the bend you need...pretty handy! I used the 120* bend and a union to connect it to the original vent hose. That original vent hose didn't have a great end on it, so maybe this is where some fuel was coming from when sloshing...I'm hoping.

The proof will be shown next week after my trip to Q. I'm leaving the curb side fiberglass cover off so I can keep an eye on this area.

Re: Fuel leak

Reply #24 – January 14, 2023, 08:59:25 pm

Keith, Hopefully you've found your leakage . We are heading to Q Tuesday. Rain should stop by then. See you there.

Affiliate Notice