Fuel Leak - Spillage and fumes

[FridayGt]

Alright, so as many of you know, I just picked this car up and it's my first classic.

So, as I'm driving it back, my friend followed behind me for the last little bit and noticed that under decent acceleration (fuel sloshing to back of tank), there was spillage coming from behind the plate where the cap is. When parked, however, there is no ground spillage or accumulation. Nothing on the floor.

When I got it home, I noticed excessive fumes coming from the back as well. The fumes leakingn from the tank are to the point whre it's definitely noticeable in the house and pretty heavy in the garage.

There's only about a half tank to a quarter tank in the car, so it's not a full tank venting in the heat necessarily. Thoughts on places to look? Where to start trouble shooting? I've got to get this thing registered and title transfered so, it needs inspection.

 

[FridayGt]

Sorry, I should mention that the tank itself is supposedly brand new and recently installed.

 

[bigmanjbmopar]

Try a new cap, I had a similar problem and replaced the old cap and fixed not only a venting issue but fumes as well. Rubber seal on old cap was worn, also make sure you have a NON Vented cap.

Another place to check is the sending unit lock nut if it was not put back on tight fuel may be venting from there.

 

[FridayGt]

Try a new cap, I had a similar problem and replaced the old cap and fixed not only a venting issue but fumes as well. Rubber seal on old cap was worn, also make sure you have a NON Vented cap.

Another place to check is the sending unit lock nut if it was not put back on tight fuel may be venting from there.

Thanks, I'll check there tomorrow. I need to pick up bulbs for my high beams anyway, so it should be either a decent run to the store or order online.

Also, not sure if it changes the answer, but my friend said that it was a very decent amount of fuel coming out the back, defenitely not a trickle, but only under acceleration, if that changes the answer any.

 

[MRHWS]

Last month when the temps were around 100, had the same issue. Full tank and gas just pouring out. The rubber seal in the cap was cracked.

 

[ChargerRTguy]

Hi, you might want to check the rubber grommit ring that fits on the filler neck that slides into the tank. I had a problem with mine, the filler neck was not lined up correctly and when the gas sloshed around or filled up the tank there was leakage.

 

[70rr-brian]

Hi, you might want to check the rubber grommit ring that fits on the filler neck that slides into the tank. I had a problem with mine, the filler neck was not lined up correctly and when the gas sloshed around or filled up the tank there was leakage.

x2 Mine had this exact problem.

 

[FridayGt]

Try a new cap, I had a similar problem and replaced the old cap and fixed not only a venting issue but fumes as well. Rubber seal on old cap was worn, also make sure you have a NON Vented cap.

Another place to check is the sending unit lock nut if it was not put back on tight fuel may be venting from there.

Checking these out tonight, going to see if I can get a gas cap from an auto parts store nearby. Have you ever tried the locking variety? I see they have one at Yearone.

Hi, you might want to check the rubber grommit ring that fits on the filler neck that slides into the tank. I had a problem with mine, the filler neck was not lined up correctly and when the gas sloshed around or filled up the tank there was leakage.

Are you referring to the rubber accordian tube, extending from the tank over the filler neck towards the cap? I saw this last night and it did not appear to be completely seated, but I wasn't certain. Looks like I'll be taking the bumber off to get to it.

 

[ChargerRTguy]

I have thought about a locking cap, especially with the "green car" people out there, never know if somebody would put something in the tank to destroy the engine. In regards to the accordian tube you might want to check it for cracks and there should be another gasket that seals the filler neck to the tank.

 

[FridayGt]

I have thought about a locking cap, especially with the "green car" people out there, never know if somebody would put something in the tank to destroy the engine. In regards to the accordian tube you might want to check it for cracks and there should be another gasket that seals the filler neck to the tank.

Well, picked up a non-venting gas cap from the auto parts store that they claimed would work. Didn't. Serves me right for not researching and hoping on a quick fix. Either way, I think the problem lies closer to the tank with that rubber accordian tube/ gasket. It seems to be most down there now and that rubber is definitely not seated against the tube. I'll post pics here in a minute once I figure out how to get to the radio to fix the stuck dial... Lol.

On a positive note, I wired the high beams back up properly and replaced the bulbs. So at least that's working now.... Lol:headbang:

 

[FridayGt]

Ok, here's the best photo I could get without digging too deep into an after work project without a solution at hand. Now, you'll have to correct my terminology, I'm new to this. When looking from underneath the vehicle The tube for filling up the tank extends into a bung on the new gas tank. It looks as though there is a dark colored (possibly brown, was using a blue led light) sealant. Not certain if this sealant was completely applied, it was hard to see. It did appear to be moist, but not certain if this was the source of the leak. My fuel level was defenitely visibly lower than yesterday without driving. Over top of this pipe between the tank and the gas cap was a rubber accordian tube that was not sealed or fastened to either end, it seemed to be just kind of hanging out there.

Alternatively, here is a picture of my puppy playing hide and seek. He hasn't grasped the concept yet that just because he can't see me doesn't mean I can't see him... Lol

 

[bigmanjbmopar]

The filler tube on my 69 RR is a solid rubber piece clamped in place. Sorry to hear the cap didn't work. Locking cap would not work for me. Are you sure all your venting tubes are in tact?

 

[FridayGt]

The filler tube on my 69 RR is a solid rubber piece clamped in place. Sorry to hear the cap didn't work. Locking cap would not work for me. Are you sure all your venting tubes are in tact?

My rubber tube that is there certainly isn't clamped down. Looks like I'm just going to have to take it apart so I can at least see it. if there are venting tubes, I haven't noticed them, any specific angles to look at that would show them without removing the bumper our dropping the tank?

If it is an adhesive matter, what kind would you use on the tank?

 

[bigmanjbmopar]

On my 69 I have 2 vent tubes , one next to the fuel line and one that you can see from inside the trunk it goes up into a u shape then back down through the floor. Search vent lines in this forum there are pics already of what they look like. I would suspect that filler tube though for just smell and slosh out. Usually you can't smell anything from the vents.

 

[FridayGt]

Thanks big time man, I defenitely appreciate the schooling a lot. Yeah, I'm defenitely thinking it's the tube now with the vast amounts that are leaking out under acceleration. Now I just need to locate the proper sealant and or clamps for a 20 gallon '72 roadrunner tank.

 

[FridayGt]

Think I finally found the thread with the info I need. Now to see if I can find this grommet at a local parts store. Downside is that I could defenitely see some sealent down there where the fill tube and tank meet. I'm wondering if it would be better for me to drain and drop the tank and to try to remove that sealant before placing the grommet there.

Or, do you think this is something that could be more wisely accomplished by removing the rear bumper to get at it?

http://www.forbbodiesonly.com/moparforum/showthread.php?t=20815&highlight=fuel+tank

Also, if anyone could give me a part number and/ or let me know where you were able to pick this part up locally, that would be awesome! Thanks.

 

[Sebring Plus]

That doesn't look right.

On my 72 Satellite the filler neck is steel, not rubber. It fits into the tank through a grommet. My grommet dry rotted and leaked under acceleration. I got a replacement grommet from Year One. Part No FD4182 or BF663. The BF part no is listed as New Chrysler, the other reproduction. They may be available from a local parts house. I Don't know about the availability of a filler neck.

Don't try to get to the tank through the rear bumper. Look up under the rear valance for two long bolts with nuts going through the fuel tank straps. loosen these with a long A@@ deep well socket and the tank will drop right out. Don't forget to disconnect and insulate the sending unit lead and fuel line.

Be Careful with a leaker in the garage. fuel vapor accumulates near the floor.

 

[FridayGt]

On my 72 Satellite the filler neck is steel, not rubber. It fits into the tank through a grommet. My grommet dry rotted and leaked under acceleration. I got a replacement grommet from Year One. Part No FD4182 or BF663. The BF part no is listed as New Chrysler, the other reproduction. They may be available from a local parts house. I Don't know about the availability of a filler neck.

Don't try to get to the tank through the rear bumper. Look up under the rear valance for two long bolts with nuts going through the fuel tank straps. loosen these with a long A@@ deep well socket and the tank will drop right out. Don't forget to disconnect and insulate the sending unit lead and fuel line.

Be Careful with a leaker in the garage. fuel vapor accumulates near the floor.

Thanks man, that'd exactly what I needed to know next. My local stores didn't carry it, so I expedited one from year one. Dropping the tank should be interesting for me... Lol, fun times. Lol

 

[FridayGt]

On my 72 Satellite the filler neck is steel, not rubber. It fits into the tank through a grommet. My grommet dry rotted and leaked under acceleration. I got a replacement grommet from Year One. Part No FD4182 or BF663. The BF part no is listed as New Chrysler, the other reproduction. They may be available from a local parts house. I Don't know about the availability of a filler neck.

Don't try to get to the tank through the rear bumper. Look up under the rear valance for two long bolts with nuts going through the fuel tank straps. loosen these with a long A@@ deep well socket and the tank will drop right out. Don't forget to disconnect and insulate the sending unit lead and fuel line.

Be Careful with a leaker in the garage. fuel vapor accumulates near the floor.

Oooh, before I forget, what did you use to support the tank on the way down? A jack with some kind of board on it so it doesn't punture?

 

[Sebring Plus]

Mine was empty

I Siphoned all the gas out, or as much as possible, so no real need for extra support Empty tank is not heavy, Maybe 20 lb at most.

You may want to pick up several feet of 1/2" or 3/4" line to siphon with, and a couple of 5 gal gas cans just in case.

I forgot to mention there are four vent lines at the top back of the tank near the differential that you may have to deal with if you completely remove the tank. It think they are 5/16", and have those permanent type hose clamps. Oh and the sending unit ground strap. It just clips on the sending unit line and the steel fuel line.