[Latitude 28]

We took a three week trip some 3800 miles and developed a fuel leak while we where on the road. 

The fuel sending unit was bad so I have been filling the tank and keeping track of the fuel burn and estimating the generator usage which worked out to be about 10% of fuel burned.  From the looks of the bottom of the tank, at some point ,it looks like the coach "high centered" over something and scraped the sump area. I think the extra weight fuel put some extra stress on the front welded seam of the sump where it attaches to the bottom of the tank causing the leak.

With a full tank we would leak about 2 gallons per day.....tapered off as the tank level came down.  Which I captured while being parked and recycled or gave to the campground owner for his tractors.  The leak is right at the welded seam of the sump and tank. Taking it to our local radiator shop where they will weld the crack and boil/etch the inside before coating it with POR15 fuel tank sealer.  He has done this to many tanks with only one returned due to not curing the sealer long enough before adding fuel to the tank.  He holds the tank 4 days to completely cure the POR.

While it is out will replace the fuel sending unit and low level float switch.

FYI, I expected all kinds of crud and water on the first drain opening.  There was none....not a drop of water....not a speck of dirt....nothing.  The hardest part was getting the fuel level down on the last leg without the gauge or low level light working, all the while we had the gen running along with the Aqua Hot.  Ended up with having to drain 35 gallons into gas cans. 

Speaking of draining....I learnt something.  Next time I will just remove the sump plug, once, and temporally install a ball valve to meter the fuel off with little more control!

[attachment=7057][attachment=7058]

Sorry about the pics being sideways....not sure what happened.  NOTE; Tried the recommended method (http://newellgurus.com/showthread.php?ti...8#pid39978) to fix the pictures...it worked!

Steve

[bestgenman]

Had the same problem.  Search for “fuel tank leak” started by jackflash and scroll down.

Opted for a new tank of aluminum rather than trying to fix the old tank.

[Latitude 28]

I saw the thread and read it completely.  I did make contact with Boyd's Welding in Ocala, FL where they specialize  in Alum tanks  They have a six to ten week lead time on a new tank.  I am going to make up a very detailed drawing and get a quote if I ever need to do this again.

Inspecting the bottom where the tank rested on the plywood there was some surface rust that may have penatrated say 10% of the metal thickness....no leaks in that area at all.  The main leak was at the welded seem which will be taken care of at the tank shop.  Going to clean up the rust and coat the exterior bottom with POR15 as well.

Steve

[Latitude 28]

Finally, tank is back installed (the second time). The original plan did not work out as the baffles in the tank prevented a good seal job with the POR15. The other issue was the size of the tank 285 gallons. That in itself prevented a through cleaning. In the process of cleaning, the shop had cut two holes in the bottom of the two baffle bays away from the sender unit. Yikes, the just did it without out consulting so I am freaking out. We decided to weld the original seam crack and move on. They welded the holes in the bottom so good to go....so I thought. Installed the tank poured the 35 gallons I had removed back in to get me to Loves for a fill up. Some where around 150 gallons I looked under the coach and lo and behold the tank is leaking in the area of the two hole cut outs. Once I got home took some good video for a meeting with the shop the past Monday Morning. I explained to them I don't pull fuel tanks for fun.....they really wanted to make this right. De-fueled 185 gallons of fuel and removed the tank for the second time! They came and picked it up Wed morning. Got it back that evening. finished the installation this afternoon and put fuel back in....so far no leaks!

I did get an estimate from https://www.boydwelding.com/ in Ocala, FL for which they would build a new one in aluminum for $4,250 and a 4 week lead time. If I have any more problems I will probably go that route.

Steve

[Latitude 28]

After removing and installing the tank the second time, it still has a small leak some place other than the original location.....GRRR! Found out from the shop that did the repair/re-work they leaked checked it with 15 to 17 PSI of air (SAFETY NOTE: Don't ever do this).  If they had really had done that kind of pressure test the loading on all the seams would have been enough to create a bomb.  I tried to explain to them how lucky they were....they really did not understand as they do radiators to 35psi all the time.  They do fuel tank repairs all the time and stated this 285 gallon tank would be no problem.  BTW they won't be doing another tank of this size.

To properly pressure check a vessel of this size it only takes a well regulated air pressure of 1.4 to 2.8 inches of mercury, measured with a Manometer and plenty of soapy water.  

Spoke with Gordon about his tank project and  checked with Newell on building a new tank or to locate the drawings....did not hear back from them.  So I created as set of detailed drawings and went to https://www.boydwelding.com/ in Ocala to have them build a new tank....attached pictures are the result.  They really do some class A work!  I had them install two 4" clean outs so the next time this comes out there will be some access to the baffled areas of the tank.  

20/20 hindsight I should have started with a new tank build in the first place. 

Currently in the process of removing the old tank for the third time. Going to do some rust clean up, painting and replacing the plywood with HDPE plastic before going back in with the new tank.

Almost forgot....Boyd's welding took my penciled drawings and created there own cut files of which they have saved if anyone needs a tank built.  

Steve

[bikestuff]

What a beautiful tank! I assume you are gonna put in a new sender? Sorry about all the hassle in getting to this point.

Bill

[Latitude 28]

Thanks, I do not want to cover it up with the SS vanity plate but my wife brought up a good point.  If we ever had a T-bone accident in that area the the SS would help protect the tank....she is so wise! 

Yes Sir, brand new fuel level sender and low-level switch....both of which did not work before all of this started.

Steve

[HoosierDaddy]

Beautiful work !!!

[Latitude 28]

Did some fuel tank bay house cleaning today.   Removed the fuel soaked and deteriorated plywood floor.  Cleaned and painted the rusted frame parts.  Installed new floor made of King Starboard (HDPE) from www.kingplastic.com.  Home Depot markets it as "White Marine Panel".  Will finish up with the tank install in the morning.

Steve

[DK on the road]

Quality looking work by both you and Boyd Welding. I'm jealous of the 285 gallons to my 205(?).

Tanks  for the lessons learned