Slow drip gas leak near filler area only when tank full (1 Viewer)

[onemudder]

Trying to chase down this leak. Like the title says gas is leaking from the fuel fill area fuel but only on a full tank. 3/4 fill doesn’t leak at all and have been going like this all summer until I could get to it now before winter hits. I’ve been searching the forms but haven’t seen anything much similar. Perhaps it’s a gasket? 2006 LC.

I’ve attached a picture and you can see one drip a stringy streak which is actually the gas dripping in motion. It is hitting the stabilizer bar if this helps to get a better idea of where it may be coming. Mind you, this is taken on my driveway which has a 20° or so slope.
The yellow area I’m pointing out shows an area where some gas maybe leaking down as well. But the only slow drip comes from the area onto the stabilizer bar.

Hoping I can just get by on a gasket and if so that it’s relatively painless.


[Maybe just another matter , but the tank does have some flaky rust on the protective coating. Also some crusty seams around the top where the lower portion of the tank meets the top portion. I be been treating the rust with fluid film over the years and seems to stopped the spread ]

 

[onemudder]

Trying to chase down this leak. Like the title says gas is leaking from the fuel fill area fuel but only on a full tank. 3/4 fill doesn’t leak at all and have been going like this all summer until I could get to it now before winter hits. I’ve been searching the forms but haven’t seen anything much similar. Perhaps it’s a gasket? 2006 LC.

I’ve attached a picture and you can see one drip a stringy streak which is actually the gas dripping in motion. It is hitting the stabilizer bar if this helps to get a better idea of where it may be coming. Mind you, this is taken on my driveway which has a 20° or so slope.
The yellow area I’m pointing out shows an area where some gas maybe leaking down as well. But the only slow drip comes from the area onto the stabilizer bar.

Hoping I can just get by on a gasket and if so that it’s relatively painless.


[Maybe just another matter , but the tank does have some flaky rust on the protective coating. Also some crusty seams around the top where the lower portion of the tank meets the top portion. I be been treating the rust with fluid film over the years and seems to stopped the spread ]




View attachment 3134118

** Just adding that it’s not the overfill area I’ve already checked that with a test

 

[ClassyJalopy]

Hard to tell from the pictures but could it be your filler pipe? My prev. truck had a similar leak and it was easily fixed by a new filler pipe.

 

[Mike NXP]

Hard to tell from the pictures but could it be your filler pipe? My prev. truck had a similar leak and it was easily fixed by a new filler pipe.

Seem like if it's only leaking over a certain level it may be more to do with the tank?? If it was the filler wouldn't it piss out all the time when gassing up? I'm not sure...


I don't have much fuel tank experience on the 100 series but I suspect there is a gasket around where the fuel pump drops in. I think you can access a sneak peak of this if you remove seats and pull up your rear carpet. Although I'm not sure how much fuel would really get out from that area either. shoot.

>> can you drop your spare tire to get a better look up in the filler pipe. Take a few more pics from further back.

 

[onemudder]

Hi guys thanks. Yes initially reading some of what’s out there I thought it might be the fuel filler pipe tube, but yeah, it only happens when it’s a full tank. The fact I went all the last six months without it ever happening again until my wife took it out and gassed it up.

Good idea to drop the spare and take a better look. I don’t think I’ve ever actually done that so good to do that fire drill regardless not to mention rust treat prep for winter up there.

 

[onemudder]

For now I was able to find this diagram and now have a better idea of what parts I’m looking at fuel inlet pipe tube, a shield, and two rings.

 

[onemudder]

 

[whitec13]

Where your filler ties in is on the other side. I just did a full fuel system on my rig and learned a lot. You do have fuel lines that run over that area and behind the tank, that jump to flex lines for your sending unit. I would inspect those. If it is indeed your filler tube, then I would point toward the gasket where it mounts to your tank. Again though, that is on the opposite side from where the bulk of your fuel appears to be leaking from.

 

[whitec13]

Also, the seams on these tanks seem to rust quicker than anywhere else on the tank as well.

 

[Mike NXP]

View attachment 3134181

Enter your info below but that website will help with diagrams.
>>partsouq

I wonder if the seam of the tank is to blame like the previous post mentioned. Otherwise there do appear to be a handful of possible suspects down there. I wonder how much of a chore it is to remove the skid plate, get all the crap out of there, and inspect. I run hose water through there often to keep all the mud out. Start soaking with PB blaster that may be your future.


** We have a drain plug on our fuel tanks? Not sure if I'd ever need that but that's cool.

 

[whitec13]

Enter your info below but that website will help with diagrams.
>>partsouq

I wonder if the seam of the tank is to blame like the previous post mentioned. Otherwise there do appear to be a handful of possible suspects down there. I wonder how much of a chore it is to remove the skid plate, get all the crap out of there, and inspect. I run hose water through there often to keep all the mud out. Start soaking with PB blaster that may be your future.


** We have a drain plug on our fuel tanks? Not sure if I'd ever need that but that's cool.

No drain plugs that I know of and removing the skid is tedious if you don’t plan to remove the tank. Once you drop the straps the tank and skid want to go, as the straps hold both up together.

Edit: my knowledge comes from a 2000 so it could differ from an 06.

 

[whitec13]

I just had the “pleasure” of dropping my crusty beast and replacing the tank, skid, all 3 fuel lines, and gaskets. Loads of fun to be had down there

 

[onemudder]

Yikes. Looks like my hope of “just” changing changing a gasket really means a Pandora’s box of work / replacement parts.
That tank alone is a big bill I’m sure.

I suppose it really pays to pay attention to this with all the crud that can get stuck sitting up on top.

How many bananas for something like this and is there a write up somewhere you followed? Thanks

 

[Mike NXP]

No drain plugs that I know of and removing the skid is tedious if you don’t plan to remove the tank. Once you drop the straps the tank and skid want to go, as the straps hold both up together.

Edit: my knowledge comes from a 2000 so it could differ from an 06.

Yeah who knows, just happened to see this on his last post with a mention of a drain plug.

 

[whitec13]

Yeah who knows, just happened to see this on his last post with a mention of a drain plug.
View attachment 3134334

Yeah that’s what prompted my edit. I know there isn’t on mine but I can’t speak for later models.

In terms of price for tanks, very, if going OEM new. I bought a used tank from out west that ran me $250 shipped from car-part.com. There is no write that I could find that gave me a full spectrum for what I was doing - by that I mean full fuel lines and such. There are some for tank dropping and skid changes where people have gotten creative to drop just the skid.

 

[whitec13]

The big plus is the flex lines on top of the tank. This does allow you to maneuver the tank without fully dropping it, if you wanted to just replace the gasket on the inlet for the filler/vent. You will just need to keep it stabilized with a Jack.

 

[Mike NXP]

This thread inspired me to take a look under and see how my tank is.

PSA - if your spare tire is taken out , you can peak your head up in from the rear of the fuel tank . From there you can shine a light toward the tank to see a bunch of mud and dirt build up.


For those of us lucky enough to not have rot yet, Get a hose up in there and flush it out to keep it that way. Flush all around the skid plate too ,bunch of dirty brown water came out.

Flushed my frame out as well to find a load of peanut shells ,no idea where the local squirrels are getting circus peanuts in the forest.