New fuel tank question

OK, I just got my new tank in, now the new one isn't like my 72 original, the old one had vents on the corners and it all went back to a canister. the new one is like everyone after 72, my question is this, I have 2 vent tubes on the left side of the tank opposite the fill tube, I would assume one is for the return line from the front, is the other the vent?? if so can I just run this to a hose that will be away from any water like the vent tube for the driveshafts?


oh and what should I paint it with, will rustoleum do? or do I have to paint it with something special for the tank steel?

 

I'm putting a new tank in my 80 right now. It's set up with the two vent lines on the left rear corner from the factory. on mine they both go up to a roll-over valve that is up in the open area behind the weelwell. and from there, there is one line that runs forward to the canister.
the fuel return line is attached to a second pipe that is in the sending unit, right next to the main feed line.
I'm not sure how your Jeep is set up, but I'd suggest one of two things.
1) install the roll-over valve and twin hoses in the rear body corner, but not necessarily connect it to a canister.
2) plug off the vents by installing a short jumper hose between the two ports, and use a vented fuel cap.
I would not just run an open ended hose up high because if you ever rolled the Jeep over the gas would just come pouring out. At least find some kind of one-way valve to put on the end.

 

OK, The 72 has only one line from the sending unit. I have a 74 tank out back Im gonna look at tommorow, it may have 2, I guess if I dont have a second one on the sending unit, can I use on the the others for that or wont they work for that?

 

I don't see why you coulden't use one of those vent ports for a return line.
Seems like It'd work just fine.
if not,
I got a new 2 pipe sending unit for $30. that included shipping, from Trail tec.

 

What is the purpose of the canister? (Thats the gizmo attached on the drivers side forward of the firewall, correct?)

 

hey tell ya what, thats worth thast just so I dont have to clean up the older ones I have, I'll take you up on the offer. PM me with contact info.

 

The canister is full of charcoal. The charcoal is used to absorb the fuel vapors from the gas tank. These vapors are later released back into the intake (during cruising speeds on the highway). This is of coarse a smog component. Fuel vapors contain an extremely high amount of hydrocarbons. If you were to hold the 'snifer' from a smog machine over an open fuel tank it would peg the machine in seconds.

 

I'll be honest that I hadn't given that canister a second thought. In Texas once a vehicle is 24 yrs old it no longer has to pass emissions, but I have a green streak anyway. After 12 yrs I would imagine it needs refreshing. Is it refillable with aquarium type charcoal, or is it replaced as a unit?

 

Replace it as a unit. Just FYI the canister is one of the main reasons it says "Do Not Top Off" at the gas pumps. Topping off can cause raw fuel to enter the canister. Once that happens the canister is no good. This has been tested by placing a canister with raw fuel in it in the California desert in the middle of the summer. No matter how long it is left in the sun the fuel never evaporates. If you've got a canister with raw fuel in it your gonna have some problems with passing smog.

Just a bit of useless trivia there.

 

Well, my Jeep is way past 24 yrs old, so no emissions tests. Just lights and stuff like that. I haven't seen the canisters in the magazine fuel system pages. Where / how does one acquire these? Is it a universal vehicle kind of item?

 

You could try an aftermarket parts store or the Jeep dealership. Some of the old emissions stuff is obsolete though. If your emissions exempt I wouldn't worry about it too much.