Fuel Tank Leak- 2002 Monaco 40DST

[Schrimscher]

Any of you had a problem with a seeping leak in the diesel fuel tank? Recently noticed that the fuel tank has a slight leak of about two tablespoons per day coming from the lower left edge where it sits on the retaining support. Have wiped it down several times and suspect the rubber pad that the tank rests on may have worn through and the tank is rubbing on the steel support. Hope to get to it in the next few days and support the fuel tank while I remove the support beam, replace the rubber pad and seal the seepage point somehow with the best external tank sealant I can find. Don't look forward to having that 100 gallon tank removed/repaired in a shop.
Anyone had a similiar problem ? Any experience/recommendations for exterior tank sealant that would work/seal in a diesel fuel enviroment?
Thanks in advance to all....this is a very helpful forum.
Paul

[Dr4Film]

Go to the SEARCH drop-down arrow and type in "Repair Fuel Tank leak", you will find some 24 discussions on repairing fuel leaks in tanks. Some of them will have a solution for you.

Good luck!

Dr4Film ----- Richard.

[MikeyG]

Paul:
Had the exact same thing happen to me on my last coach (2002 HR Endeavor). The rubber pad wore out and the metal to metal rubbing wore a hole in a weld at the point of contact. Too big a job for me, so I had RMechanic fix it in Livermore. They are not cheap, but IMO do a first class job. Use them on the repairs I can't do.
Good luck.
Mike
2008 Camelot 36 PDQ
2007 Jeep GC

[Schrimscher]

The fuel leak is stopped that I reported in my original thred. Thanks to all for the advise and info.....it was a big help. The leak was coming from the left front support bracket where it was welded to the fuel tank and was leaking about a tablespoon per day. After cleaning and sanding I could see it weeping around that weld. Taking the tips from others, I built up 4 coatings of J-B steel epoxy Weld...that ALMOST did the job. Still had small wet spot, so I sanded the J-B Weld and applied a dab of Permatex Instant Gas Tank Repair. Stopped the leak and hope that it holds with proof of time and travel.
FYI, I started figuring out WHY the weld started to leak?? I found the rubber/neoprene material underneath at the four welded attachment brackets had deterioated which probably allowed some flex/stress on the one weld joint....I made up some new rubber spacers of the right thickness to replace the four worn ones. The material directly under the tank was okay. THEN, I looked further and found that both OUTSIDE edges of the tank were not being supported or even making contact with the support rails at the outside edges. There was a 1/4 inch gap between the bottom of the tank and the support railThis meant that all the weight was riding on the steel frame "Cradle" and four attach points in the CENTER of the tank. With no support at the outside tanks edges, I figure the tank would have a tendancy to "teeer-todder" on those four weld attach brackets as fuel slooshed around inside during curves, bumps, etc. The tank extends about 30 inches outside of each side of the attach points...enough, I think, to put a stress load on the weld joints. I made up some shim material to fill the gap between the bottom of the tank and the outside support. Now the tank rests on the center "cradle" AND the outside supports.
Don't mean to be so lengthy, but wanted to share my findings and repair in case you want to check your tank support points. My patch may/may not hold..time will tell. Another tip....I later found that there is a fast acting J-B Weld that would be easier to work with in vertical/bottom position than the regular kind that I had. I had to wait about 30 minutes after I mixed it, to get it stiff enough to keep from dripping off. Use the faster stuff.
Thanks to all and hope you never have this problem. This may help if you do.
Paul

[Schrimscher]

Response to RonNBAma....I tried reply to your email but the the iRV2 privacy blocked it. Hope this helps about the material I used under the hold down angles.
The tried to find a neoprene or some material that would survive in a diesel fuel enviroment at several local auto shops....no luck. Finally settled on a 1/8 inch thick rubber sheet from the hardware store because we were hitting the road. Since the leak is fixed, this should do until I can find a better material. I cut pieces to fit and stacked a couple pieces where I needed to. It's been 2 months since the repair, 800 miles and no leak....the J-B Weld and Permatex is holding. Keeping a close eye on it and hoping for happy travels.

[Radarman]

Paul,
Thank you once again for the great writeup on this problem. As you know from our PMs, I am going thru the exact problem. Getting a handle on the leak now, and should get it stopped soon. I have been able to slow it considerably using different products. Just a very slow seap left to go. Mine is located at the right-front "L" bracket. The original black cheap rubber strips are just not enough to support that much weight over time. Just as a side note, I e-mailed Devcon and they recommended a 1 minute epoxy or gas tank repair putty (Quick setting) to temporarily stop the leak or slow it down enough to apply their titanium 2-part epoxy putty later. For now I am trying their 1 minute epoxy and then their Plastic Steel epoxy. I also have new 1/8" rubber strips ready to go along with what's left of the original rubber strips. I would recommend everyone check the clearance between their 100 gal. diesel tank bottom area where it contacts the 2 support "L" beams. Be sure you have some clearance/rubber contact left. If in doubt, loosen the 4 "L" bracket bolts (9/16" nuts), and jack one side of the tank up at a time. Be careful to not jack up too much due to clearance of top connectors on tank. Slip in some additional rubber material any way you can. Believe me I wish I would have known about this potential problem before it started leaking. Easy to work on a non-leaking tank. Not so much when it has 75 Gal. of fuel and leaking. Also, when done, coat bottom of tank with black evaporative cooler water pan waterproof paint. It is a thick coating that will help with preventing corrosion and rock dings from damaging bottom of tank.

[Schrimscher]

Radarman,
Thanks for the heads up on Devcon....I'll store that in my coach info file and might pick up some just to have on hand. Also, great idea on coating the tank with evaporative pan paint. Between all of the ideas from everyone, I'd say we "got her done". Hope your clearance/support at the outer edges of the tank was better than mine....I had about a 1/4 inch gap that meant no support, thus a teeter-todder effect on those center tank brackets.
Hoping you have many "no leak" miles ahead.
Paul