Ok Guys this has me going crazy.

I just picked up a 2009 f350 dually 6.4. I have been driving it for a week or so in florida and just drove it back to NY i did not notice any leaks while it was parked on a concrete driveway in florida, I'm sure i would have seen it. I am home now and parked it in my driveway last night , when I moved the truck this morning I had a 2 ft circle of Diesel right below the tank toward the rear.

I would have seen a leak like this in florida. I power washed the entire bottom of the truck and tank area. and drove the truck again. When I looked at the tank I can see diesel fuel wet on the driver side of the tank. It looks like it is coming from the Top ??? somewhere and running down the sides dripping on the guard plate under the tank and then exiting out the hole in the plate. After an Hour about a 8 " circle of fuel on driveway. Fuel Tank is about 2/3 to 3/4 full right now

First these tanks are plastic, it is a southern truck no rust. I cant believe fuel could slosh out a hole?? and it leaked while sitting in the driveway. I will look at it again in the daylight tomorrow morning but is has me puzzled.

Any thoughts are appreciated.

 

I just bought a 2010 6.4 and its been an adventure changing all the fluids and filters and identifiing all the leaks and remidiating them.

are you sure the leak is not the primary fuel filter which is located under the driver in the inside of the chasis frame....quite possible the fuel is running done the frame to the tank area. primary fuel filter leak could be as simple as a pinched Oring or improperly installed filter .

 

I will check the fuel filter but the only area I can find that is wet at all is on the side of the tank itself, I don't have any other drip spots under the truck except directly under the tank , I can kind of see where the tank guard plate is wet from the fuel dripping on it and accumulating then exiting the hole in the plate,

I can't believe the tank has a crack in it, i am trying to look up how the fuel fill lines are attached at the top impossible to see. I will try and take a few pics maybe I can IM you and send them to you Thanks for your help.

 

Just spit balling, did you notice the leak after a re-fuel? Could be as simple as a loose hose clamp or cracked fueling hose.

 

I did a full tank refuel while in florida no leak, I refuelled 4 x on the drive back to NY, did a full Tank refuel about 100 Miles from home. then parked the truck until morning saw the leak immediately the next day i have a concrete driveway so easy to see under the truck. I thought about since I was trying to put alot of fuel in the tank neck and fill tube included that I may have overfilled it and some fuel got pushed out the top of tank somehow and go trapped and leaked later, But i drove the truck 110 + miles home also washed the truck yesterday , degrease and power wash the tank and surrounding to try and clean any fuel from sitting on the guard plate etc.

Went out this morning drivers side of tank is wet, a good 1 ft circle of fuel under the truck I cant find any other signs of wet diesel anywhere else under truck.

 

Looks like that spit ball was deflected. I have seen the top of the tanks on my 550 there are a couple of fuel lines one of them being return. coul be leaking on the return and running down. Also there is a five or six screw cover/fuel pick up return assembly that has a gasket on it. and a couple of vent looking deals I know nothing about but the are held in by a do-nut grommet. After verifying no problems with these I would say cracked tank. REMEMBER>>> if fuel can get out water can get in.

 

This is my first 6.4 had a 2000 7.3 Prior, I have never dropped the tank on these trucks. very obvious to drop the tank guard plate, but do you know or anyone if I wait till I burn off some fuel and get the tank low to eliminate some weight can u un bolt the
tank straps and just drop the tank straight down, will the fuel lines come with it, or do you have to unhook everything, fill tube and fuel feed lines prior to lowering,

I will try and look up more info but any help is appreciated

 

I dropped my mid ship. The fuel lines had enough slack I did disconnect the fuel fill but mines a flat bed. I would try to run till fuel was low. I used a two ton floor jack to let her down easy. Harder to put it back than to drop it of course. needs to be in the right spot for the strap bolts to start easy.