yesterday. i topped off my tank with a couple of gallons of diesel i had in my shop. about an hour later- i noticed a puddle under my truck. diesel fuel was leaking down the side of my tank and dripping onto the ground at a pretty good pace. i did not have time to investigate further,etc at the moment-my in laws arrived last night from out of town. but i did notice that when it cooled down outside-that it stopped leaking. i left my house at 11am this morning and it was dry under the truck. when i arrived home about 3pm-it was leaking. as i write this right now, it is 8.30pm and cooler outside and it has stopped leaking. any ideas???? it has never done this before-obviously. i wont have time to look at it until my in laws leave-which is on monday. thanks.

 

I think you are looking at this the wrong way, this could be your blessing:
In-laws in town = get under truck and take a look
Football game on = get out from under truck and watch game
repeat by finding other things wrong

Seriously though... craw under that thing and give it a look already!

 

Possible return line leaking or dirt in fuel tank vents causing tank to build up some pressure then leaking out from fill hose or vent hose. Remember not to top off a diesel fuel tank room needed for fuel expansion.

 

i know diesel fuel needs rooms for expansion- just had a couple of gallons laying around ( i noticed) when cleaning up the shop- so i dumped it into the tank. i do have the vent mod kit on my tank which should have nothing to do with my leak. may be able to find time tomorrow to look at it.

 

I don't think diesel expands like gas does, they use the same tank on the gas trucks, that's why we can do the mod to get more fuel into it.

I bet if you've done the vent mod it's gotta be leaking there, that or something with your FASS install.

Tell me bout your control arms, are they adjustable or ½" longer?

 

controls arms are dt pro fabs. i bought them raw and powder coated them orange. they are the stock length. but they do sell them 1/2" longer,though.

 

I think it's just expansion even though I always top mine off with no issues. I do NOT have the fuel tank vent mod done so mine has room for expansion. Yours, on the other hand, has no where to go except onto the ground.....
My 1992 Ram Diesel would always do what yours is doing when I topped it off..

 

yeah-but this is the first time it has done this. vent mod has been on the truck for 3 years. i have topped off the tank many times before all the way up to the filler neck-never had this problem before. might be able to get it on the lift tomorrow.

 

Ley us know what you find? Maybe you'll be able to see something just removing the inner fender.

 

If it's only doing it when it reaches a certain temp then that's got to be it. It's kind of funny. I have a squeaky upper control arm and it only squeaks when the temp is 80 or above....

 

My old 96 leaked when it was full. Turned out that the filler tube had rusted and had pin holes in it.

 

I had the same problem. Found that it only occurred when I topped off too much. On the top of your tank there should be a fitting that is plugged off with a short piece of rubber. Check to see if the end is dry-rotted. If it is, go to the auto parts store and buy you a vacuum line plug, end of problem.

 

Have seen leaks because of a lose clamp on the hose that connects the filler neck and the tank.

 

going to wait a couple of days before i drop the tank. the tank is full at the moment. why wrestle with a full tank of diesel!-thanks for the suggestions-will post what i find out.

 

For sure, run it down first, then do what I did.
You can take the FASS return line off and put it into a gerry can, with the motor running the FASS will empty your tank for you.