I noticed over the last month my fuel cap door wasn't closing.
took the back carpet panel off just now and it looks like my fuel tank has collapsed in on itself like getting sucked into its own black hole.

what on earth would cause this?

and how the hell do I blow it back up?

 

I once worked with a British guy that told me he used to EXPAND motorcycle fuel tanks that had been 'dented in' during crashes.

He would clean and flush them and then put a spray (ether??) or gasoline into the tank. He shook the tank and then threw a lit match into the filler.

He was lucky a few times and it expanded the tank back into shape (sort of).

He blew one up and was slightly injured and gave up on the repair procedure.

Just reminiscing!!!!!!!!!!!!!!

bob gauff

 

wow i got to see this

 

Fuel tank not venting right.

 

+1

If the vent gets stopped up the pump can pull vacuum and cause them to collapse.

 

cheaper and faster fill ups!

on a more serious note perhaps it can be expanded back out with slightly drama than the above method by sealing all but one opening and pumping in hydraulic fluid .. it is less risky than pumping in air.

 

I tried using my compressor. on the top of the tank.pulled the metal hose that goes into top of the tank. got it to somewhat blow back up but air was leaking out of the black valve.
and I think some place else. it's still outa shape. idk what to do.

 

At this point I would get a tank at a junkyard.

 

Used to happen to my MGB, wasn't venting. Used to hiss when I pulled off the gas cap.

 

This is crazy

 

NEED PICS! The old dual tank Jags use to have a problem with collapsing tanks, but I've never seen an actual picture of the phenomenon leading me to file it away into the "Urban Myth" category like blumpkins & bellyriders. But you can change that with a pic!!!

 

Please don't try the ether/gas and a match method. I tried this way back in the 70s with a dented motorcycle tank. I lived without eyebrows for months. And it didn't work, split the tank at the seam.

 

Check your Rochester Valve

 

I just replaced it about 3 months ago, i was having the "take the gas cap off blowing out gas and air issue"

 

your gas tank is only connected to the rochester valve, purge valve, and charcoal canister. Disconnect the vacuum hose coming from the purge valve into the rochester valve. If this cures the problem I would suspect the purge valve.

 

Funny... till someone loses their eyebrows!!

You mean "re-inflate" the tank....

How about a suction cup dent puller?

 

Exact same happened to me today!!! Noticed the fuel flap was sticking up and wouldn't close because the cap was too high. Whipped out the carpets and lo and behold the tank has completely collapsed on itself!!! It was so caved in that the retaining straps were completely loose!! There had been absolutely no drivability/starting issues up to this point

Don't think that it will be easy to re-inflate so I'm on the lookout for a used tank. Will have to check the whole evap system too

Actually it's pretty scary as it looks as though it could rupture at any moment!!

Here are some pics

 

Allan. if that car was blue I'd swear it was mine.
what I did was stick my air compresser blower hose in the top valve, amd blew it back up.
I had to have somebody hold down the tank cap. 1st try worked ok. but my tank was on empty. what I did which is probbaby really dangerous was fill the tank as much as I could and did the same thing and it blew back up to its original shape.


my problem ended up being that I installed my new Rochester valve backwards.
fixed it all and no problem. then a week later some lady crashed into it while parked and totaled it.

 

Yikes, sorry to hear about the accident

That's always something that hovers a bit in the back of my mind about anything I've put a lot of work into, that in a moment someone else (or nature) can undo it all. Not a reason to quit making the effort of course, but a real shame.

.

 

Shawn,
I think I will try your technique first and see. I am a bit concerned about the structural integrity as there are some pretty significant creases but it's worth a shot. The tank is about half full so I'm sort of in no man's land.