leaking gas tank

[Boosted516]

I was standing outside my car and i smelt gas, so i look under it to see if my lines were leaking again and this time its my tank leaking. Its weird because a spot bubbled and is soft and its leaking through there. Ill get pictures tomorrow. I just want to know what could have caused this?

 

[gaboonviper85]

Rust

 

[Mikael_7m]

I have a leaking tank too, though it only occurs when I tighten the fuel cap and the pressure builds. Ive been a little dodgy and just screw the cap a little looser than normal.
Its probably bout time i repair it..!:biglaugh:
Is it dangerous to weld a fuel tank even if its out and fully drained...i.e. fumes....and boom!?

 

[fool'ssupra]

That section is probably rusted out. The tank is plated steel for corrosion resistance but can still rust from the inside or the outside. Gas tanks getting small perforations in them aren't uncommon on older cars. It's possible to fix the holes but it's usually easier to get a replacement tank.

 

[fool'ssupra]

Mikael, welding a gas tank is pretty iffy. You're correct, it's the fumes that cause the problem. Also, if you weld the tank you'll burn off the protective plating on both sides of the steel, which will lead to future rusting.

 

[tissimo]

My car is from up north and had a leaky tank. IT wasn't rusted though, but the seam started leaking. Maybe it was just defective but probably the road salt had to do with it.

I just found a replacement and put it in (luckily i had my old 91 still sitting in the drive for parts, haha)

 

[Boosted516]

damn i really dont wanna drop my tank considering i just changed my pump

 

[Mikael_7m]

Mikael, welding a gas tank is pretty iffy. You're correct, it's the fumes that cause the problem. Also, if you weld the tank you'll burn off the protective plating on both sides of the steel, which will lead to future rusting.

Hey man, so what do you reckon is the best thing to do, try one of those repair kits? it didnt work for me the first time, but maybe i should try again....:icon_mad:

 

[fool'ssupra]

The old-school way to fix tanks was to clean the perforated area, apply soldering flux, and solder a small piece of copper over the hole. The solder melts at a low enough temperature that the plating isn't damaged. These days there are repair kits on the market that use a metalized epoxy. The biggest problem with any adhesive is getting the surface absolutely free of rust and contaminants, such as oil or gasoline residue.

 

[Mikael_7m]

The old-school way to fix tanks was to clean the perforated area, apply soldering flux, and solder a small piece of copper over the hole. The solder melts at a low enough temperature that the plating isn't damaged. These days there are repair kits on the market that use a metalized epoxy. The biggest problem with any adhesive is getting the surface absolutely free of rust and contaminants, such as oil or gasoline residue.

Yeah sounds right man, as the first time i did the tank, my hands were greasy when mixing the two adhesive materials together...:biglaugh:
gotta take time and do it right!! :aigo:

 

[Boosted516]

any tips on dropping the tank?

 

[Boosted516]

am i gonna have to jack the car up or can i just put a jack under the tank?

 

[Boosted516]

couldnt get the line off the fuel filter, tried using line wrenches and breaker bars and still no luck

 

[HommerSimpson]

Soldering tank is not hard to do... but you will need a oxy/ac torch or a propain one.. and one of these.. i have done a few .. and some still full of gas...

 

[shaeff]

Yeah, I wouldn't do any welding on the tank, or soldering, or anything unless the tank was removed, emptied, and pumped full of CO2 so you don't blow yourself up.

Didn't you just do the fuel pump? So you had to drop the tank once already, the second time should be a snap! I dropped my tank two times in two weeks. The second time only took me 20 minutes to get it out.

If you've got a few days to spare, spray everything with PB blast a few times a day. By the third day, everything should come right off. Also, keep in mind that the fittting on the fuel tank hardline does NOT spin- the fitting on the SOFT LINE is the one that spins! Make sure you're wrenching on the right one.

You should have one line wrench on the steel line (which has a fixed nut, cannot be moved)- and another wrench on the nut for the softline that screws to the hardline. Lefty-loosey, and it should come right off.

Some of the old hotrod guys empty the tanks completely, (and I mean so they're dry), and hook up a hose to the exhaust of another car and run it into the tank. The exhaust will displace any oxygen (which is needed for an explosion to occur), thus making welding of the tank a safe practice.

 

[Boosted516]

today was my only day to do it for the next week so im gonna stop by autozone and get some of this pb blaster. detonation666 just told me to get that, so im gonna spray it for the next few days, then drop it next monday hopefully. would taking the line off at the fuel filter be any easier?

 

[shaeff]

If you can reach it. Whichever works for you, as long as you get 'em all pulled before you drop the tank. (and disconnect the wiring from the hatch access panel)

 

[Boosted516]

If you can reach it. Whichever works for you, as long as you get 'em all pulled before you drop the tank. (and disconnect the wiring from the hatch access panel)

i tried both with no luck