Hello, all. The problem is a metal tank in an 84 car that is leaking from somewhere towards the top of the tank. I am looking for options before pulling the tank out as I don't want to car out of service for too long.

Can I swap a late, plastic tank (which I have) for the metal one if it turns out to be toast? I know that the support straps are different but not a big fab problem.

As an alternative, what repair methods are there to repair leaking metal gas tanks?

Big Dog

They often crack up by the filler neck. A late tank can be swapped in - you'll need the tank, with the fuel pump, and the late crossmember, and trans mount. The early crossmember needs to be cut out, and I believe the late style on welded in, which is a bit of a PIA from what I've been told. Also, make sure your trans is compatible with the late trans mount - that it has the holes in the upper/center of the trans to hang it from . Most do.

I will check the trans to see if it has the late mounting option. The leak appears to be on the drivers side, not the passenger side.

Go back with an early tank. I have tried it before and it is a ton of work and will require some welding. Also, make sure when you change out the tank you check the lines on the tank. We had an issue recently with one of our cars where a fuel vent line went bad and was spilling fuel out when the tank was filled. A real pain the butt to fix.

Have you checked to see if it is a vent line leaking?

I have not yet pulled the tank out to see what is leaking but it was leaking while sitting on the lift for several days so I don't think it is one of the lines on the top of the tank.

If the tank can not be repaired, I will have to source an early tank as all of mine are late, plastic tanks.

Big Dog

my early tank had cracks where the vent line crossed the top. removed tank cleaned filled to the cracks with water and welded.