The Stovebolt Site Forums The Shop Area General Truck Talk Proper Fuel Line Components and Shape for 1957 3100

I'm putting my original gas tank back in the truck. I've found the fuel tank pickup line (steel) that was in it when I got it.

The 1957 assembly manual manual (Section 8, Sheet 2.00) that covers multiple years shows the pickup line leaving the top of the sending unit and going straight down to a hole in the floor, connecting to a short flex hose, then on to the fuel pump (presumably). My pickup line, however, is bent such that it heads toward the passenger side at about a 30 degree angle. Now there happens to be a floor hole there that is 1" in diameter. Three questions:

1. Should the pickup line go straight to the floor, meaning someone bent mine wrong?

2. Should it have a flare fitting on the end that connects to the flexible line?

3. Did the Task Force trucks use the flex line? Or a shutoff valve?

I'm thinking one of the POs for this truck bent the line for some reason and cut it at the pump end for another.

The manual shows grommet number 3708176 (not in the parts wiki any more) that appears to exit the floor at about mid-cab. In my cab, I have no hole there, but I have a 3/4 hole near the driver's side tank strap and a 1" hole near the passenger side one. Which of these, in a 1957, should receive the pickup line?

Any help is appreciated.

-Jim

EDIT: Here's an online auction site listing for a same year tank that shows the pickup line in the same orientation as mine. Still can't see the end to determine whether there's a fitting at the pump side: link

The fuel line goes out the passenger side hole in the floor; OR... whichever side corresponds with the side of the engine your fuel pump is on... Edit - in this context all fuel pumps are on the passenger side; the assembly manual shows "R.D." & "L.D" differences.

I've removed old flex lines off of two TF trucks. That's all I know.

Sheet #7 (section 8) in the manual probably shows a better diagram(?).

Brad (just 1)

Thanks Brad,

I'll have a look at that page. Assume when you removed the flex lines, the pickup tube had a flare fitting attached? Looks like I'll have to make one up with similar bends. At least I have a 'go-by.'

Appreciate the help.

Jim

Now that I do not remember (flared ends).
I remember the flex lines because it is a convenient cut point. Both myself and my buddy wanted new everything fuel related, so we weren't salvaging. BUT, the replacement flexible fuel lines sold by vendors are flare fitted at both ends.

I bent my own line from the sending unit to the flex line (it goes directly to the frame at this point ), and I flared both ends with fittings to match what they needed to. I have pictures somewhere.

So, you ended up with the flex line connected at the point where the fuel line gets clipped to the frame?

Pics would be great, but if not, no worries. I think I get the picture. The flex line is still important and needs to mate up with a flared fitting from the line that leaves the sending unit.

Thanks,

Jim

Simply put: it is easier to bend a rubber fuel line.

You'll want to bend it (where it exits the cab floor) 90° or so to go straight to the frame rail; up & out of the way of the parking brake assembly, et cetera.

Brad

Another question for you:

Do the asphalt pads get glued to the tank, the floor, or under the bottom seam? If so, what do you glue them with? I got the pads from Classic Parts but the manual isn't clear on where they mount (antisqueak set) and how.

Thanks,

jim

Basically you find a premade line at O'Reilly's that fits the sender/pick up female. A line that you bend and route similar to the orig. Down thru a grommeted hole and aimed at the frame. Then you slide the nut back on that end of the premade steel line, slip a piece of rubber fuel line on it with a clamp. Other end of rubber hose attaches to the fuel line (slip over it with a clamp) that goes forward. This line is clamped to the frame as it travels toward fuel pump. The idea is to provide a flex between body mounted hard line and frame mounted hard line...or hard mounted frame line,,,whatever!

There is no need for a flex right after the pick up/sender line because there is no relative movement between tank and body.
The flare on a premade line that is for the flare nut is also a perfect barb for the rubber hose. No special hose or line is required.

I would not use a shut off valve, the outlet is not gravity fed so no problem with repairs.

The pads are mounted at rub points. Under where straps go around top and where tank rests. It will be obvious when you are assembling. They probably will stay where you put them. A thin dab of silicone won't hurt. They may not have been bonded, it may be that the old tar type melded to the metal.
Anti-squeak is also anti-rub-thru-the-tank during very small vibrations.

The 2 or 3 bends you put in the line between sender pick up and near frame act as anti vibration coils. I believe there are/were clamping points for that line inside cab and maybe under floor.

It is also necessary to have a rubber hose section between frame line and fuel pump. A good way is short rubber hose, then metal can Filter tied to frame, then rubber up to pump.

I agree, the asphalt pads stay where they are put with the tank straps clamping them in place...no glue required.

Mike B

Awesome responses. Thanks Mike, Uncle Brad, and Bartamos.

I think I remember scraping some type of tar paper off the floor when I was cleaning up my cab. There was none stuck to the gas tank. I'm assuming the tar pads lift the bottom of the tank enough that the seam doesn't rub in the long channel where that sits. Or maybe it's the humps where the straps bolt down.

I should be able to get this plumbed in today. Truly appreciate the advice.

Jim

Picture link.

Jim, these pictures probably won't help you, but this is the first chance I had to look for pictures. There will be some irrelevant pictures on the link, but the fuel-related pictures are from a 55.2 3100 (3104).

Brad

Actually helps a lot. Looks like I got the thru hole correct. I love the red paint.

Thanks for taking the time to send this.

Jim