For whatever reason, whenever I fill my tank like past 3/4 full, the gas pours out the gas door while I drive. I cant figure it out, except that I filled the tank full TWICE yesterday for my ride up to NH and back down. (wanted to get that cheap Mass gas, 2.93 a gallon and 2.97 a gallon). Anyway, it has been pouring out the gas door so bad, it leaves a puddle on the ground wherever I park. Right now, the tank isnt even full and i can see it dripping down the quarter panel. I need to get that painted now because all the clear is gone!

I put a new gas cap on when I bought the car. However, the little flapper that covers the hole in the filler neck is gone. I figured a good gas cap with a good seal would keep the gas in there though.

I just cleaned the quarterpanel this morning. I see this after I just go for a quick ride:



You can also faintly see where it was pouring out when I was driving, and dried up.

 

I believe the filler neck is bent, preventing the cap from sealing off.
I would get another one from a junkyard and replace it.

 

Do you know if the filler neck comes off the tank, or would I have to cut it with a sawzall and use some radiar hose and clamps to connect the new one?

 

I don't know if the neck on that model is made onto the tank or not. I do know that radiator hose will not work with gasoline.
Of course the sawzall motors have brushes that make sparks... which cause gasoline vapors to explode. Be sure to shoot video.

 

From a distance.....

 

Well when we put a body lift on my buddies fullsize, the filler neck would no longer line up. So the lift kit came with a piece of hose that looked like some sort of big radiator hose and 2 hose clamps. We sliced the filler neck, bolted the top half inside the gas door, and connected them with the hose. Worked fine.

 

Yep. The camera needs to survive the initial fireball.
Seriously, if the neck is made onto the tank, I'd change the tank.
Now, you can do a search for "fuel pump replacement" to get the 2 schools of thought about how to go about dropping the tank.

 

hmmm mine does the same thing and i too replaced my cap but, i highly highly doubt it has anything to do with a bent filler neck. I mean i'm sure it may not be perfect but, that gasket should count for something and mine to seems like a real leak not a slight 1 lol........ Anyways maybe i'll just glue a thick peice of cork to the other gasket and c how it does.

 

The neck on my '88 does not bolt to the fender. It sticks up thru a "cup" with a boot.

 

If the tank seriously needs to be replaced, I just wont run a full tank lol. I have seen that you have to drop the rear end and exhaust to replace the tank, neither of which I am capable. (Unless it involves using a sawzall, torch, or plasma cutter. Which in this case would be counter-productive lol)

That is the same thought I had too. I dont see how one would even bend that metal, you would really have to yank on it with somethin. And the cap screws on no problem. I was thinking I wonder if there is any tube of sealent like RTV but resistant to gas? Put a bead of that on?
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So doesent mine but I am sure I could rig something up.

 

Dropping the tank doesn't require anyting more than undoing the (2) tank strap bolts for the tank, removing the gas door & sheathing (boot), undoing the driver side pandard bar bolt, other brace bolt and lower shock bolts...and jacking the rear end up. That's pretty much it. VERY easy. Heres what it looked like right when I took the tank out :

 

I agree that it's probably not the filler neck or the tank. Mine leaks really bad too, so much so that I epoxied the two pieces of the gas cap together to disable the ratchet and enable me to tighten it more. It still leaks and hisses really bad venting excess pressure when I loosen cap. I believe it might be the tank pressure control valve up by the emissions canister. I going to go that route when I can find a replacement valve.

 

Does yours **** out the gas door too?

 

Whenever the tank is more than 3/4 full. It helped some when I disabled the ratchet on the gas cap, but, yeah it still leaks down the quarter panel.

 

this is realy a crazy weird situation isn't it i wish there was a simple solution but, gas is pretty nasty stuff so i'm not realy sure what will help seal it????

anyways i only run at max 1/2 a tank and i still get fuel all over my quarter panel. Of course thats mostly because, i drive like its an autox day everyday i get in my car but, still....

it's pretty rediculous and it tends to drip on my borla exhaust to, makes me quite uneasy. I know undercoating go's up in flames nicely and i could just c me having a small fire and my car going up like *puff the magic dragon*.

 

Yeah same here, between the leaky rear pinion seal, and the gasoline, my undercoating in the rear end is all mushy and falling off lol.

 

lol exactly sounds like me n u are in the same boat for sure.....

i've got a rebuilt engine n tranny and new clutch but, the rear leaks from all orifices since it has 205k on it (not easy miles either).

i'll figure it out 1 way or another but, until this thread i was convinced that i'd have to drop the tank to fix the problem. which i realy don't want to do ......

 

any1 have any more luck on fixing this problem i havent played with mine yet unfortunately but, still have the problem, looking for a simple solution

 

I've never had gas leak out of the gas tank...but due to the frustration of getting the tank back into the position I bent the neck down slightly. Then had problems getting the cap screwed on. I VERY CAREFULLY

 

I haven't ever had a problem with gas leaking from the gas cap, but due to the frustration of getting my gas tank reinstalled I did bend the filler neck down slightly to get the tank back into position. After that I had problems getting the cap screwed back on. I VERY CAREFULLY inserted my factory tire iron into the filler neck and pryed up on it to bend the filler neck into position which helped but did not completely solve the problem. Maybe this "technique" will help with your gas leak. If the cap is sealing properly there should not be any liquid escaping. I did not remove the boot from around the end of the filler neck, maybe this will further the effect of prying the neck upward.
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woops...

 

mine leaks out of the damned filler neck i dunno y....... makes no sense...... i have no clue maybe theres a pin hole i don't c or something. I think i might try drilling a hole in the top of my gas cap for a vent cap just in case its over pressurizing or something crazy i dunno lol that makes no sense but yah neither does it leaking out of the filler neck with a new cap and new seal when the filler neck is straight.

 

mines never leaked until today,i filled up ,parked it at home ,10 mins later i smelt gas in the garage and seen a puddle behind the drivers side rear tire...idk wtf,do they have a overflow valve or somthing,cause i did top off the gas,maybe i over filled it?,I do see some gas on the heat shield,nothing on the body or around the cap...any ideas?

 

Mine leaked just like that. It was caused by me taking off all the charcoal canister emmisions crap, thinking that it was causing my rich running condition. I later fixed my carbureter that had a stuck primary rod and just left the emmisions disconnected and plugged. As soon as I would fill up with gas and drive away, gas would start trickling out the gas door. I reconnected all the charcoal canister emissions and it stopped. I do still have a slight hiss after opening the cap on a hot day, but nothing bad. Check your charcoal canister hoses and valves.

 

It sounds like you guys have plugged evap systems somewhere between your tank and your charcoal canister. I would look their first, when you remove the fill cap do you get a poof of gas fumes?

 

when I release fuel cap I actually hear the tank flex like its releasing its self from being imploded,and the whoosh noise,its sound like its sucking air in...yea id say its plugged,thats why im looking for the vented gas cap.hopefully thats a quik fix?

 

why not just fix the problem instead of putting a band aid on it and if you are getting a woosh that means there is pressure so it is not imploding it is exploding because of the fumes.

 

Just started having the exact same problem last week. Worst part is that I just completed about a month ago a brand new fuel tank, sending unit and fuel pump replacement. Swapped the gas cap already, checked lines upfront for emissions but need to go at it again with the manual to make sure I got them all.

Going to replace the valve thingy attached with a hose to the gas tank as soon as I find one.

 

i am also having the same problem but my started after i dropped the tank and put a new fuel pump in it, the filler neck where the cap goes got bent up a little bit and now the car leaks gas from the filler cap i was thinking more a long the lines of finding like a universal cap and trying that to see if it works or helps in any way.