Gas tank sealing question:

[Captain D]

Hi all,

Hope that this is being posted in the correct location (if not, we can always relocate). Anyhow, I was curious to get some insight if I may please regarding the seals on the gas tank. Reason being:

On my 69' Charger, I have all new stuff - gas tank, sending unit, fuel lines, etc. However, if I fill anymore than say $22 worth of gas (or if the front of my car is at a downward front angle), I tend to leak some fuel. To be more specific, it's not the actual long filler tube from the gas cap where the fuel is first supplied, but rather, where the fuel lines and sending unit are attached to.

I suppose what I'm trying to learn here is this - when I take the car to the shop & have the tank dropped, what seals, gaskets, grommets, etc. would I need to get that hole sealed up & secured properly? The shop encouraged me not to buy anything as they may have a variety of seals & so on already there in their inventory (and 'factory' correct isn't crucial with me anyway - if it works, call it done). But, just in case I would 'need' something specific, I'd like for them to have it on-hand vs. the car simply sitting several days for a part to come in before they can resume work on it.

Any and all info would be greatly appreciated. Thank you for your time,
Aaron
 

[cdr]

Find an original lock ring, the new ones are thinner & softer.

[Captain D]

Thanks man for your reply,

I kinda figured that was the item I am in need of. But, hmm, it may be a challenge to find a NOS lock ring. If there is none to be had, does there happen to be a repop brand name that is better than others, just out of curiosity?

And lastly, and a dumb question here no doubt, but to swap out one of these fuel lock rings - does the tank have to be dropped or can they be done (have enough room) to do with it still installed? Just calculating time + labor = $$.

Thank you again for your time,
Aaron

[71charger_fan]

You want Mopar 4279445. There are plenty out there.

[Captain D]

Thanks man, how about rubber gaskets? Did the originals use them or only the lock rings altogether? Reason being, a lot of repop kits seem to include them (could be, like it was mentioned, the newer lock rings are so thin they include the gaskets as part of the kit). Thank you once more gents for all of the speedy & helpful replies n' info!
Aaron

[cdr]

Thanks man for your reply,

I kinda figured that was the item I am in need of. But, hmm, it may be a challenge to find a NOS lock ring. If there is none to be had, does there happen to be a repop brand name that is better than others, just out of curiosity?

And lastly, and a dumb question here no doubt, but to swap out one of these fuel lock rings - does the tank have to be dropped or can they be done (have enough room) to do with it still installed? Just calculating time + labor = $$.

Thank you again for your time,
Aaron

it can be done in the car, just make sure the fuel level is below the sender.

[JR]

Ive had this problem with a stock fuel tank before.

In my case I didn't have the lock ring rotated to the correct spot. But to be safe, I also stacked two gaskets together. Double gaskets made the ring harder to rotate than normal, but it made a great seal.

That cured my leak completely.

You'll probably have to drop the tank to access the ring.

[timmycharger]

I would still give it a go without dropping the tank. Trying to solve my own leak I must have had that sending unit in and out at least 4 times in 2 weeks.  I jacked up the drivers side rear high enough to get the axle to droop on one side, used a jack stand for safety, took off the rear wheel, then was able to squeeze under there with enough room to get a good view of it.  Its a great ab workout as well since you are in the "crunch" position for a while  .

I just picked up a NOS ring and will try my luck with that, I do like the 2 gasket idea though 

[cdr]

I have done it MANY times without dropping the tank, jack up the car,put jack stands under the frame near the front of the leafspring, let the differential hang, PLENTY of room.

[birdsandbees]

I just picked up a NOS ring and will try my luck with that, I do like the 2 gasket idea though 

So it was you that stole the only one showing on ebay, that I had marked to buy tonight.. 

[JR]

I had no idea you could replace it without dropping the tank. I never even tried that.

[timmycharger]

I just picked up a NOS ring and will try my luck with that, I do like the 2 gasket idea though 

So it was you that stole the only one showing on ebay, that I had marked to buy tonight.. 

Most likely    there was another one this morning. I havn't checked since though.

[Captain D]

Great info and discussion gents  ,

When it comes to gaskets, that wouldn't have to be NOS necessarily would it? In other words, if I bought two reproduction gaskets along with the NOS lock ring - I should be good to go, eh? I'm sure any local auto parts stores (Advance, Auto-zone, NAPA, etc.) selling these gaskets would serve okay...

Thanks again for all of the helpful info as we finally get after the leak this Saturday!
Aaron

[ACUDANUT]

My might as well replace the tank as well.  They are not meant to be used over 10 years imo.

[birdsandbees]

My might as well replace the tank as well.  They are not meant to be used over 10 years imo.

Really... mine was 47 years old when I removed it last year for the restoration, zero leaks. If it wasn't covered in undercoat and crap I probably would have reused it instead of buying a new one. Now the new one might only last 10 years compared to '60's steel! 

[timmycharger]

You want Mopar 4279445. There are plenty out there.

Are you sure about that part number? Picked one up and put it next to one of the aftermarket ones.  Looks a bit big compared to the one that I was using   

[Captain D]

Oh man, I too just bought a NOS lock ring (part# 4279445) with two repro gaskets. I may have to cancel the appointment at the shop if this isn't the correct item that I need too. Glad that you posted the comparison pic there timmycharger.

Hoping that we clarify this soon so that we can find the correct part number if need be...

[68 RT]

4279445 is for 80's 90's cars.

[timmycharger]

Super!


Lesson here is trust but verify!


Hey birdsandbees, still interested in the 4279445 ring? 

[Captain D]

Ugh, okay...so, what is the 'correct' NOS part number for a 69' Charger lock ring, lol? Now, I'm debating whether or not to keep the appointment at the shop to have mine replaced tomorrow morning. If I do, I wonder what the results may be if I simply use all repro stuff (repro lock ring, but using two gaskets as reinforcement). The repro lock ring from Auto-Zone is a Dorman brand, which I've heard some good reviews. Any thoughts...?

[timmycharger]

Saw this one on Ebay

https://www.ebay.com/itm/1957-1978-NOS-MoPar-Sending-Unit-LOCK-RING-300-Fury-Charger-GTX-Cuda-Dart-Duster-/142015687206?hash=item2110cb6a26:m:mU14DCqi-fk7O6UtzL_Z1sA&vxp=mtr


for this price I may take a chance, and if it doesn't work, go with the 2 gasket idea.

[birdsandbees]

Super!


Lesson here is trust but verify!


Hey birdsandbees, still interested in the 4279445 ring? 

DANG!!! Thanks for saving me!! 

[Captain D]

Didn't have time to see about another NOS, so I simply went with a Dorman repro lock ring w/ gasket. The shop noted that all went well & things are looking good with a nice / snug fitment. That's the latest. Thanks for the info + interesting thread, lol...

[71charger_fan]

Sorry about that if I gave the wrong part number. Means I likely have a ring on the shelf I can't use.

[Captain D]

It's all good, my friend, as I know that you were simply just trying to help. And, it all worked out in the end  . Hey, we learned something new too, lol. Take care & my best to you guys,
Aaron

[Kern Dog]

Hi all,

Hope that this is being posted in the correct location (if not, we can always relocate). Anyhow, I was curious to get some insight if I may please regarding the seals on the gas tank. Reason being:

On my 69' Charger, I have all new stuff - gas tank, sending unit, fuel lines, etc. However, if I fill anymore than say $22 worth of gas (or if the front of my car is at a downward front angle), I tend to leak some fuel. To be more specific, it's not the actual long filler tube from the gas cap where the fuel is first supplied, but rather, where the fuel lines and sending unit are attached to.

I suppose what I'm trying to learn here is this - when I take the car to the shop................

Any and all info would be greatly appreciated. Thank you for your time,
Aaron
 

Really? Take the car in for someone else to work on it? These cars are barely more complicated that a VW Beetle. I am sure that you are smart enough to fix the car on your own!   

[Captain D]

Thanks man, lol. Eh, a nice lift at the shop came in handy / easy to make the swap - plus, we utilized the lift to actually raise the tail end of the car higher in the air to double-check for leaks as a pretty cool feature,  .