Need some help! I spent the whole morning yesterday replacing the rubber fill neck hose on my pickup. Everything was pretty straight-forward and went well for the most part. Here's where things went bad fast.
I have a '78 Ranger XLT Short-wide 4x4 with the (single) rear mounted fuel tank. My first question is.....Should it have a drain plug? It has a very small screw right in the center of the tank and the little rubber seal was leaking fuel. So I drive all over town trying to find a small fuel-type o-ring and end up settling for the only one close to the size I needed. I install it, put fuel in it and all is good. Then, my wife and I leave to go run some errands and I come back 2 hours later to find my pickup leaking fuel all over the driveway. Basically it was 103 degrees here yesterday and the tank pressurized and it started peeing out of this screw. I removed the fuel cap and it stopped leaking. So, if this drain plug is supposed to be there, where do I find a seal for it? And what kind of a breather should the tank have. It seemed like an excessive amount of pressure when I removed the fuel cap and I noticed when I had the tank out that there was a hose that came out of the top of the tank but it was plugged off and then taped shut. Any help would be greatly appreciated!

 

There shouldn't be any kind of drain plug. Either someone put it there because they "thought" it would be a good idea, or someone drilled the tank to steal the gas at one point and that's how it was repaired.

There were two types of venting systems - the original sealed-tank style with a vented cap, and evaporative emissions. The first kind vented to the atmosphere through the filler cap. The second kind vented to a charcoal cannister on the frame rail through a fume line along the passenger side frame rail.

 

That's what I thought too! So now I have to replace the gas tank.

I must have had the charcoal canister version and I'll bet that they cut that hose and plugged it off and threw out the canister because I know mine is missing. So do I just need a vented gas cap or is there another way to do it? I don't want to install another canister.

 

There are two different fuel tanks for your truck, depending on whether you have evaporative emissions (charcoal canister) or not. The differences in the tanks are w/ evap. emissions the tank has a hole in the top for a check valve that a hose hooks up to. The non-evap. tank doesn't have this hole. The other difference is the vent hose that hooks up next to the fill hose is on the opposite site of the filler.
The tanks themselves directly interchange without any problem but you will have to get a longer hose for the tank vent.
If you're going to change the tank anyway you could get the non-evap. tank and do away with the check valve and lines.
The other important thing is if you do switch to the non-evap. tank you must use a vented fuel cap or you could collapse the tank.