Diesel overflow spillage problem

Common for our era of truck but easy to fix.
Put your hand up on top of the tank and feel around where the fuel line and sending unit are.
You will find a plastic nipple that's about 3/8's to 1/2" diameter. This nipple is used for gas trucks and was often just left open to the air. A few, like mine are sealed but most were wide open. You can put a rubber cap on it to seal it up. Even if this weren't the problem, it's good to seal it up rather than let road spray and dirt get in. Dodge had to do a lot of repairs back n the day because of this and often soaked the customer for it.


Also, the sending unit and line connections are sealed with a mason jar style threaded ring which is often loose. Tighten this ring if you can (my truck leaked when I filled it and I was able to turn the lid almost 4 turns). Sorry but I cant remember if the nipple is the white thing in the pic below or if it was within the mason jar lid.
Here is a pic of the tank and the mason jar lid (dirty white thing).
Ram fuel tank

I thought spilling fuel on the ground was just something diesel folks did as a practice. The diesel lanes are always filthy, it's really annoying when the diesel and petrol pumps are side by side and I have to be walking in diesel with good shoes on

GordonThree wrote:
I thought spilling fuel on the ground was just something diesel folks did as a practice. The diesel lanes are always filthy, it's really annoying when the diesel and petrol pumps are side by side and I have to be walking in diesel with good shoes on

Lol, funny stuff, unless you realize gas slobs spill more gas than diesel slobs (by virtue of sheer numbers).
Why does diesel slobber look bad?? Because it doesn’t evaporate to nothing like gas.

So yer sort of annoyed at yer own ignorance?

Scott is right. Bore scope light on cell phone made job easy to find problem. Had hard time getting new oem lug. Wound up with rubber tube and hose clamp. If not problem re post.

joe&julie81 wrote:
Saturday morning I was fueling my Dodge Cummins and was topping it off for the first time in a good while when I heard fuel splattering on the concrete underneath. I thought "oh no" I'm leaking somewhere! I didn't seem to have a leak in the tank itself so I went on with my relatively short trip, with no further issues. Maybe I just overfilled it and it came out the spout, but I thought it was coming from behind or below that. Maybe a venting issue? Is this nothing to worry about or should I investigate deeper?

I believe you have the "no fuel cap" filler hole, just insert the nozzle, right? Well there's another flapper door below the first one and in between there's a drain hole should any water(rain or over zealous pressure washing) happen to make it past the first one. If you read your manual, (you did that right), it also says to wait about 5 seconds before removing nozzle. You went beyond overfull.

Here's a copy and paste from a RAM site:
I had this same issue when I first got my truck, the dealer inspected it, they even cleaned up all the mess that was left from the leak. (except for my garage floor that is.....lol)
They gave me a copy of a notice from FCA explaining the problem with pictures.
There is a drain hole above the 2nd flap. So you have to keep the pump nozzle all the way in - keeping the 2nd door open - after you finish filling the tank with fuel, for at least a few seconds to make sure all the fuel drains in.
I stopped jamming my tank full and by leaving the nozzle all the way in and shaking it a couple of times before removing, I haven't had this problem again.
Is kind of a pain in the ass.
I guess it is a good safety in case water gets by the main fuel door, at least it wont go into the tank. But it does make a hell of a mess when it is fuel leaking thru.

My 2015 has two flaps in the filler neck. If you were topping off did you pull the nozzle out a little? If so you may not have opened the inner flap. Found this out trying to pour in some fuel treatment from the bottle. The neck wasn't long enough to open the inner flap and the treatment spilled to the ground.

joe&julie81 wrote:
Saturday morning I was fueling my Dodge Cummins and was topping it off for the first time in a good while when I heard fuel splattering on the concrete underneath. I thought "oh no" I'm leaking somewhere! I didn't seem to have a leak in the tank itself so I went on with my relatively short trip, with no further issues. Maybe I just overfilled it and it came out the spout, but I thought it was coming from behind or below that. Maybe a venting issue? Is this nothing to worry about or should I investigate deeper?

The Rams have a second flap down in the filler neck to protect against foaming blowback. If the filler nozzle isn't inserted fully, the second flap isn't opened and diesel will spill onto the ground through the overflow in the filler neck.

I had this happen once while I was doing a visual top off. Now I fill until the nozzle clicks, wait a little while and fill again until nozzle auto shuts then I'm done. No spill problems with this method. Probably giving up a little tank capacity.

Thanks for your insight. It could be either of the scenarios you all
are describing, either way seems relatively easy to resolve. Puts my mind at ease as it could have been something more serious.

Lol, funny stuff, unless you realize gas slobs spill more gas than diesel slobs (by virtue of sheer numbers).
Why does diesel slobber look bad?? Because it doesn’t evaporate to nothing like gas.

yea you pour a cup up gas out and it will be gone in 20 min. You pour a cup of diesel out and it will still be there a year from now