LEAKING FUELTANK!? - Diesel Forum

REINB · 08-19-2007, 02:34 PM

Hello all,

I have been running B100 in my truck (2004 6.0) for around 20,000 miles and I have not had a single problem. However, the other day I noticed a black spot on my concrete drive. After sliding under the truck to inspect it looks as if the fuel tank is leaking. The frame rail, skid plate, etc. are all damp. I think it must be coming from the top of the tank & seeping down. I thought that all new vehicles used rubber compounds that were ok with biodiesel. I don't know if it matters but I have a tool box tank (91 gal.) I have been keeping this full for the past couple of months. It just feeds the tank via the filler neck, keeping the stock tank full at all times. I shut the tool box valve off so that the main tank level would drop and hopefully so would the leak, until I can fix it. What do you guys think?

Spencnaz · 08-19-2007, 04:56 PM

I don't think it's a problem with biodiesel eating hoses. Sounds like you're front tank just got over filled from your tool box tank.

I've had this happen with my setup. Did you perchance use that kit from Northern Tool that is supposed to automatically shut off? I manually turn the fuel shutoff and don't rely on that check valve, it's never worked right anyway.

REINB · 08-19-2007, 09:22 PM

Hey,

Thanks for your response. It only has one tank. It is an F350 Crew Cab - Long Box. Yes, the tool box kit was purchased from Northern Tool. It is very simple though, it does not use a check valve. It has around a 3/8 or 1/2 inch outlet line that runs into the a "Y" adapter that is inserted into the fill neck. When the tube gets full the flow is stopped. All of those connections and hoses look very dry. It has been in use now for almost a year. I just wonder why now. I don't even know what is on top of the fuel tank to leak? It may have a bad spot in the plastic? Any ideas? [img]/ubbthreads/images/graemlins/shrug.gif[/img] [img]/ubbthreads/images/graemlins/shrug.gif[/img]

Albin · 08-20-2007, 07:31 AM

At least three or four people (or more) here have reported leaking OEM fuel tanks at that same location. At least one did not have an aux fuel tank; his leaked when he filled to the OEM fuel door.

The leak is probably coming from the OEM fuel tank vent. It's supposed to have a check valve (like the RDS gravity feed) but it appears to fail sometimes.

The dealer should fix it if you're still under warranty. See if you can get him to do the harpoon mod while he's in there.

Good luck.

Al

REINB · 08-20-2007, 08:31 AM

I just recently installed a new camper shell on the truck. Is it possible that the shell has allowed the tank to become hotter than normal and build excess pressure, causing the check valve not to work? It has also been very hot here latley. (90 plus days!) Should I take the time to drop the tank and investigate or should I just clean it up and try different approaches to see if it is still leaking. The truck is out of warranty, so any work I will have to do. Also what is harpooning the tank, I have heard about it many times on here but I don't really know what it is or why it is an improvement?

Sparkydm · 08-20-2007, 09:47 PM

Others have reported salt/gravel getting under the straps and wearing/corroding through the top of the tank. Just something else to look at.