Fuel leak

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jjr329

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Some co-workers noticed raw fuel dripping down from around the rear license plate today when I hit the gas.

I think its the rubber seal between the filler neck and the tank. I seem to remember this thing being a pain to replace. Does anyone have a DIY for checking/replacing it? Does the tank need to be dropped?

Thx

 

72HCODE

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oh boy it is quite a bear to deal with especially if you have fuel in the tank.

you should be able to swap the gasket with the tank in but it won't be easy usually you install the neck gasket before the tank goes on so you may start this project and end up having to dump the tank anyway.

now it could also be a problem with the seal at the top of the tank with the vapor return line being clogged or the rubber hose on the vapor system has falling apart as well. if it keeps leaking you will have to drop the tank to inspect that.

So dyi procedure.

first vacuum the trunk REALLY well all the loose rust and dirt make sure you get it nice and clean to prevent the dirt from falling into the tank.

you might want to unbolt the trunk lid and remove it from the car this will gain you a lot of clearance, mark the hinge plate on the trunk lid before you pop the 4 bolts and note any body spacers you will need to put back later.

remove twist on gas cap, and unbolt the i think it is 6 self tapping screws from around the fuel filler to body.

next inside the trunk on the floor around the filler neck you will see a rubber gasket that has 4 self taping screws holding it to the floor, there may be sealant also.

after unscrewing the 4 floor screws pull up the rubber gasket the neck should now be free there will be a cork gasket between the filler neck and the body of the car inside the truck.

with the floor gasket up you can shine a light at the tank seal gasket and see what it looks like but the back half will be obscured by the taillight panel and angle of view.

push the filler neck by the gas cap into the truck and then start pulling up on the neck you may need to twist it allot to get it out.

the neck will pop out and expose the tank seal gasket it is a doughnut with a cut in the center that holds on to the lip of the tank.

pull or cut the old seal out. be careful don't lose anything inside the tank, this is why people work on the tank off the car because you can turn it upsidedown and get the seal out without getting stuff into the tank.

once the seal is out, replace with a new seal, it will be very hard to install and not let it fall into the tank, you have to work it to sit well on the tank lip and not stickout at all.

now the pure hell part, reinstalling the filler neck. 1) make sure you replaced the trunk floor gasket (i would) stretch it onto the filler neck half way up. 2) have a new cork gasket ready for the filler neck to body connection. but leave it on the side till later.

now getting the neck into the tank will be pure hell it is EXTREMELY TIGHT. just FYI i had to use a 1000 degree heat gun to soften the rubber gasket on the tank so i could push my filler neck in. obviously you cannot do that on a tank full of gas and i tried grease, and even fuel as a lubricant and i had to use that heat gun and even then it took me hours to push that neck into the tank far enough to line up with the body.

Now as a short cut you could get a fuel safe sealant and fill up all around the original filler neck gasket that would save you a ton of work but be a questionable repair.

once that neck is back down in the tank and the cap area lines up with the taillight panel, then you put the 5-6 larger bolts through the tail panel through the cork gasket and into the neck itself.

double check the tank seal at this point make sure the thing didn't falling in or you have to do this again. then pull down the rubber floor gasket and you can use a bead of sealant around it and then push it down and install the 4 screws again. then put the gas cap back on and you should be good to go.

if you took the trunk lid off then obviously that goes back on.

now if it leaks again, you could have a pin hole leak on the top of the tank or a issue with the vapor return line. either one means the tank has to be drained and taken out.

 

OMS

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I have the new parts in stock

Don

Item #D1ZZ-9072

71-73 FILLER NECK TO GAS TANK SEAL

Reproduction filler neck to fuel tank seal. Obsolete from Ford, replaces part number D1ZZ-9072. Price: $19.95

Item #D1ZZ-9008

71-73 TRUNK FLOOR TO FILLER PIPE SEAL

Trunk floor to fuel tank filler pipe seal. Price: $21.95

Item #C5ZZ-9076A

65-73 GAS NECK TO BODY GASKET

Cork seal. Price: $0.60

 

jjr329

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Found the problem, the rubber gasket is gone! I assume its floating around the tank somewhere. I'm on vacation for next two weeks so I guess I just added another project to the list.

 

OLE PONY

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oh boy it is quite a bear to deal with especially if you have fuel in the tank.

you should be able to swap the gasket with the tank in but it won't be easy usually you install the neck gasket before the tank goes on so you may start this project and end up having to dump the tank anyway.

now it could also be a problem with the seal at the top of the tank with the vapor return line being clogged or the rubber hose on the vapor system has falling apart as well. if it keeps leaking you will have to drop the tank to inspect that.

So dyi procedure.

first vacuum the trunk REALLY well all the loose rust and dirt make sure you get it nice and clean to prevent the dirt from falling into the tank.




you might want to unbolt the trunk lid and remove it from the car this will gain you a lot of clearance, mark the hinge plate on the trunk lid before you pop the 4 bolts and note any body spacers you will need to put back later.

remove twist on gas cap, and unbolt the i think it is 6 self tapping screws from around the fuel filler to body.

next inside the trunk on the floor around the filler neck you will see a rubber gasket that has 4 self taping screws holding it to the floor, there may be sealant also.

after unscrewing the 4 floor screws pull up the rubber gasket the neck should now be free there will be a cork gasket between the filler neck and the body of the car inside the truck.

with the floor gasket up you can shine a light at the tank seal gasket and see what it looks like but the back half will be obscured by the taillight panel and angle of view.

push the filler neck by the gas cap into the truck and then start pulling up on the neck you may need to twist it allot to get it out.

the neck will pop out and expose the tank seal gasket it is a doughnut with a cut in the center that holds on to the lip of the tank.

pull or cut the old seal out. be careful don't lose anything inside the tank, this is why people work on the tank off the car because you can turn it upsidedown and get the seal out without getting stuff into the tank.

once the seal is out, replace with a new seal, it will be very hard to install and not let it fall into the tank, you have to work it to sit well on the tank lip and not stickout at all.

now the pure hell part, reinstalling the filler neck. 1) make sure you replaced the trunk floor gasket (i would) stretch it onto the filler neck half way up. 2) have a new cork gasket ready for the filler neck to body connection. but leave it on the side till later.

now getting the neck into the tank will be pure hell it is EXTREMELY TIGHT. just FYI i had to use a 1000 degree heat gun to soften the rubber gasket on the tank so i could push my filler neck in. obviously you cannot do that on a tank full of gas and i tried grease, and even fuel as a lubricant and i had to use that heat gun and even then it took me hours to push that neck into the tank far enough to line up with the body.

Now as a short cut you could get a fuel safe sealant and fill up all around the original filler neck gasket that would save you a ton of work but be a questionable repair.

once that neck is back down in the tank and the cap area lines up with the taillight panel, then you put the 5-6 larger bolts through the tail panel through the cork gasket and into the neck itself.

double check the tank seal at this point make sure the thing didn't falling in or you have to do this again. then pull down the rubber floor gasket and you can use a bead of sealant around it and then push it down and install the 4 screws again. then put the gas cap back on and you should be good to go.

if you took the trunk lid off then obviously that goes back on.

now if it leaks again, you could have a pin hole leak on the top of the tank or a issue with the vapor return line. either one means the tank has to be drained and taken out.
WARNING!!! I've always heard not to use a vacuum cleaner around gasoline vapors. So if your seal is gone and you suck vapors into the vacuum the sparks created by the vacuum motor can explode the vapors so be extremely careful!

 

jjr329

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My trunk is clean as a whistle so I won't be blowing myself up. Good info for others that might not have thought of that!

 

OLE PONY

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Not sure if this is an urban legend or a true story, but the story went that some guy thought he could start siphoning his gas tank by using a vacuum cleaner and blew his self up!

 

Bill73Ragtop

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a) there is a video somewhere showing a vacuum cleaner igniting fuel vapors...but I would think the electric motor would have to be in rough condition and sparking to cause that. My shop vac has a pretty long hose which would prevent any issues like that.

b) when working in the trunk changing out your gasket, MAKE SURE YOU HAVE PLENTY OF VENTILATION!! I had a close call one time while changing the neck gasket - the trunk will trap the vapors....

 

alvi

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Last week I had a similar problem with another car gas tank leak, I think I had like 1/2 tank of fuel still on the car, I went to Harbor freight Tools and get a Pittsburgh Multi-Use Transfer Pump Item # 66418, a manual pump. It worked good for me....... quickly transfer the fuel to a gas container without any problem.Maybe with these kind of tools you'll be used twice and then trow away, but they're helpfull (cheap) at the moment you need them.

My recomendations.

1.- Check it out before you spend some money buy it, then you decide.

2.- Read completly the instuctions, and again if you think is not safe........DO NOT USED.

3.- Try to used in a good ventilation area, fuel comes with a big pack of flammable fumes.

4.- Avoid any electrical ON/Off activity close to the siphoning area

5.- Manual pump gets a little bit warm because the friction, so if you thing got hot, stop for a while.

Hope this helps.

 

jjr329

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Last week I had a similar problem with another car gas tank leak, I think I had like 1/2 tank of fuel still on the car, I went to Harbor freight Tools and get a Pittsburgh Multi-Use Transfer Pump Item # 66418, a manual pump. It worked good for me....... quickly transfer the fuel to a gas container without any problem.Maybe with these kind of tools you'll be used twice and then trow away, but they're helpfull (cheap) at the moment you need them.

My recomendations.

1.- Check it out before you spend some money buy it, then you decide.

2.- Read completly the instuctions, and again if you think is not safe........DO NOT USED.

3.- Try to used in a good ventilation area, fuel comes with a big pack of flammable fumes.

4.- Avoid any electrical ON/Off activity close to the siphoning area

5.- Manual pump gets a little bit warm because the friction, so if you thing got hot, stop for a while.

Hope this helps.
I tried to siphon out old gas a long time ago and I could never get the tube into the tank. I ended up pulling the line at the tank and got it that way.

 

jjr329

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Only took a couple min to get the new rubber gasket in. Pushed the new gasket in and then used a little marine grease in the gasket and neck to slide it right in. Piece of cake!

 

72HCODE

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Awesome, you got super lucky. Mine was pure hell.

Only took a couple min to get the new rubber gasket in. Pushed the new gasket in and then used a little marine grease in the gasket and neck to slide it right in. Piece of cake!
 

gatormc9

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I'm so glad I was able to find this thread. I just my car up and running and to date I've only filled it with a 5 gallon can. I had some spillage but I chalked it up to the can. Today I drove it to the gas station and gas dumped all over the place. It turns out that the filler neck was never seated inside the gasket when I changed the tank out. A little lithium grease and it slid right in. I'll try it again in a little while and see if it fixed it.

 

jjr329

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Nice, glad my thread is helping others. :)

I haven't had any problems since.

 

Paul of MO

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I used a little PB Blaster on the seal and the filler neck slid in like butter.

This may be a great time to replace the gas tank. New ones are fairly cheap and can be bought in kit form with the gaskets and sender.

They sure look pretty all shiny and new!

- Paul

 
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