What do you think caused this?

[Hoosierman]

I know I just replied, but something didn't seem complete about my reply, so here it is.

Do you know how brand new assembled gas tanks are tested for leaks? Once the tank is assembled to be shipped to the automaker, before it can pass final inspection, each tank is placed inside of a sealed chamber and helium is pumped inside and out of the tank. If helium can get past the seals, so can gasoline. It's the ultimate leak finder- helium. So let me tell you something else; even the smallest, narrowest friggin' chin hair underneath the o-rings will cause a leak. You absolutely and positively must ensure your o-rings, locking ring, and encapsulated ring (the one moulded into the tank) are totally spot free. Otherwise you will have a leak. When I replaced the gas tank on my '84 two months ago, I made darn sure those were spotless.

If you have even the smallest gouge on the surface beneath the o-rings. You will have a leak. Any imperfection on underside of your o-rings will be a good source for a leak.

Forgot to explain that. Hope that helps you and others understand.

 

[bobbywalter]

old tanks i will usually just make my own sender plate or a lock nut out of 10gauge...or a custom fat bastard o ring. i have o ring stock and super glue. get er did.

 

[rusty ol ranger]

So to update...

I dropped the tank yesterday. Found the lock ring did infact back itself off roughly 1\8 of a turn.

So i took it off, pulled sender, cleaned it all up and put new o ring and lock ring on.

The new lock ring went on much harder and tighter then the other one....more the way im used too. So far so good

 

[Hoosierman]

So to update...

I dropped the tank yesterday. Found the lock ring did infact back itself off roughly 1\8 of a turn.

So i took it off, pulled sender, cleaned it all up and put new o ring and lock ring on.

The new lock ring went on much harder and tighter then the other one....more the way im used too. So far so good

That should be the fix, I would reasonably surmise.

 

[ekrampitzjr]

The irony about all this: when I was going to the big swap meets at Carlisle and Hershey in Pennsylvania years ago, I remember a vendor with a sign offering the lock ring tool for $5. Didn't have a Ford pickup then.

 

[rusty ol ranger]

That should be the fix, I would reasonably surmise.

Fingers crossed im sick of dropping the thing

As a bonus i found out my gas gauge is way off...it said 1/4 tank i siphoned out 15gallons

 

[Hoosierman]

Fingers crossed im sick of dropping the thing

As a bonus i found out my gas gauge is way off...it said 1/4 tank i siphoned out 15gallons

Now that's a mystery to me, somewhat. Granted, I saw brand new senders in the factory that gave faulty readings all the time, and many would totally fail a continuity test altogether.

Not sure about this one, but I wonder if the gauge needs to be somehow reset or calibrated.

 

[rusty ol ranger]

Now that's a mystery to me, somewhat. Granted, I saw brand new senders in the factory that gave faulty readings all the time, and many would totally fail a continuity test altogether.

Not sure about this one, but I wonder if the gauge needs to be somehow reset or calibrated.

I dont know, im not super worried about

 

[Terrys87]

I get the o-ring that is squared all the way around. It is a difficult fit as I have to have someone help push down while I turn the lock.

 

[Hoosierman]

Honestly when it comes to fuel, if it's tighter than a bull's hind end in fly season, that's the way you want it.

 

[Shran]

The lock rings suck (usually too small and don't engage the tabs on the tank) and the O rings often suck (they will absorb gas and swell up slightly larger than they should be.)
New sending units are garbage a lot of the time too. Brand new Delphi one from Carquest reads backwards... Rock Auto special was dead accurate sometimes, and sometimes way off... the one my kid put in his F250 recently reads full until you get down to 1/2 tank, then it stays there until it's empty. I don't know why they can't make these things work right, it's not rocket appliances.

 

[Hoosierman]

That has me a little concerned because when I put in a new tank on my '84 about two months ago, I had to install a new FSU also, and I got one from LMC. I haven't been able to get my truck to start lately and I don't know if the FSU works or not. It didn't seem like a really high quality part.

Ya know, one could probably just as easily install an aftermarket fuel gauge. But I'm totally on board with making the original gauges work. It just feels off when they don't.

 

[svtcards]

I put the fuel tank back in my B2 and its leaking AGAIN from the sender o ring.

Same place it leaked after i installed the tank the first time.

That time i blamed it on the fact i reused the old (but still new) O ring.

This time the o ring is new from bronco graveyard.

I got it togther roughly a week ago and ive been driving it all over hell (even filled the tank) and last night i went to run up to subway and smelled gas when i parked. By how much it was dripping i figured it was a line.

Got my food and went back home, found out it dont leak unless i hit the brakes and it sloshes.

O ring, sender, tank, and lock ring are new. Just tired of pulling the tank every week.

Any idea?

 

[svtcards]

I had same issue happen to mine a mth ago after I filled it. After filling it I walked away to the store. I looked back and saw gas gushing up the top. After I drop the tank I assumed it was coming from o ring also .But it wasn't. It was coming from the ring that dorman welds onto the tank where the sending unit sits on when u put into the tank. I ended up using permatex moto seal and ran a bead all way around it. Let it dry for a few days. Added a couple gallons of gas tipped it so sending unit was at and angle enough so gas got to where I sealed it. No more leak. I'm assuming that steel ring isn't a sealed unit. So if you don't think it's o ring it might not be .it might be that steel ring welded on the top. You just need to look closely to see exactly where it really coming from.

 

[Hoosierman]

I had same issue happen to mine a mth ago after I filled it. After filling it I walked away to the store. I looked back and saw gas gushing up the top. After I drop the tank I assumed it was coming from o ring also .But it wasn't. It was coming from the ring that dorman welds onto the tank where the sending unit sits on when u put into the tank. I ended up using permatex moto seal and ram a bead all way around it. Let it dry for a few days. Added a couple gallons of gas tipped it so sending unit was at and angle enough to gas where I sealed. No more leak. I'm assuming that steel ring isn't a sealed unit. So if you don't think it's o ring it my not be .it might that steel ring inside. You just to look closely to see exactly where it really coming from.

Are there any opinions on the aftermarket polymer fuel tank that Graveyard sells? I'm thinking that will be the next tank I put in when the current one inevitably begins to rust.