Gas Tank Return Spout, Cap It or Run a Line to Filler?

[justinevert]

Since I scrapped the emission crap, do I cap the "return" spout, or do I run a vent line to the filler?

Since I am running and electric pump do I not want to have any trapped air or does it make a difference at all?

I don't have any gas smell running this line, as a test.

Thought?

TIA!!

Justin

[Chamonix72]

Does your fuel filler neck have a vent? If so, you can cap the return line.

[eastsidebimmer]

if your gas cap is unvented the tank "could" pressurize somewhat during extreme increases in temp without some type of vent. You can always go Enviro-retro like the early cars and route the vent pipe along the tail panel and through a hole in the trunk floor (should already be there w/ a plug in it) Early cars use a cone shaped vent tube grommet - Try (16 12 4 480 140)

[justinevert]

That is one of my concerns, especially in Texas and the heat we face here.

There is an small opening on the filler elbow where I canrun the line to so that any vapor does not get loose and the tank can "relax" when one open the cap.

[harry6422]

I am installing a electric fuel pump right now as part of the restoration of my 75 2002. The the interior is out of the car so the 2 plastic lines , fuel supply and evap line, that run inside the car from the trunk to the engine compartment are assessable. I was moving them around and with very little pressure they broke in several locations . They are VERY brittle from age and I would say a major safety issue running fuel through at any pressure!!. With no need for a return line using a electric pump, I am going to block off the fuel return fitting on the tank and use the steel return line , that runs under the car on the drivers side, as my supply line, I am keeping the evap system so I bought some 8mm nylon fuel line to run a new line from the vapour storage tank to the engine compartment . These lines lines could be the source of the gas smell problem inside that car owners comment on? For safety CHECK these lines in your car and and replace them with new nylon fuel line they use in the new cars.

Harry

[eurotrash]

Justin, if you are referring to the return line at the engine bay, and you don't at least cap it along the frame rail, it WILL siphon gas when the tank is full and dump on the street. Happened to a friend of mine...

-Wait, really. A friend. I swear. I actually still have the recirc valve.

[justinevert]

Well, here is another question, if I decide at a later date to convert to EFI can use that tank spout as a return line?

Justin

[eurotrash]

Well, here is another question, if I decide at a later date to convert to EFI can use that tank spout as a return line?

Justin

As stated above, after a good inspection for not cracks and/or smashed portions, some choose to use the former return line as the feed in an electrical pump configuration. And then the former feed line as the return. Sighting concerns that the original feed line isn't safe under EFI pump pressure..

Although, some might argue that the Tii pump is pushing something like 38 psi, and that the factory feed line is totally adequate. And I believe that I recall something about the factory feed line being "self sealing" in the case of fire..? But I could be very wrong on that one.

[harry6422]

Just another thought, as brittle as I found the plastic feed line in my 75 that runs along the passenger side floor just below the door sill, and you don't have a intretia safety switch installed in the electric fuel pump circuit, and you get hit hard on the passenger side, that line would shatter not bend or seal it's self. If you were injured and couldn't or didn't think about turning the the key off , the pump would continue to run filling the inside of the car with gas!! Not a happy ending

[TobyB]

If you want to feel REALLY good about that line, take it out and try to set it on fire.

Yep, burns nicely.

I burnt mine with a welder.

On purpose.

Honest.

t

[FunkyLaneO]

The plastic fuel hose that runs in the passenger compartment is not intended to ever be pressurized, if you use an electric fuel pump in the back of the car use the steel return line as your fuel supply line. That plastic hose is designed to be suction only and is supposed to seal itself off (like shrink tubing) if it ever comes in contact with flame.

Under suction if it ever develops a leak all it will do is suck air, under pressure it will fill your passenger compartment with gas.

And to answer your question, that return opening will not make a good vent, cap it off. It is too low on the tank, the vent should be at the highest point (on the elbow where it is now).

[Simeon]

if your gas cap is unvented the tank "could" pressurize somewhat during extreme increases in temp without some type of vent. You can always go Enviro-retro like the early cars and route the vent pipe along the tail panel and through a hole in the trunk floor (should already be there w/ a plug in it) Early cars use a cone shaped vent tube grommet - Try (16 12 4 480 140)

Doesn't that picture already show a vent routed up to the filler neck? What would the other vent (to the ground) do other than allow expanded gas to be dumped on the ground?