PTFE/AN Fuel Hose? Hardline Tubing Frame to Block Fuel Pump Jumper?

[Loose Screw]

I'm wondering if steal braided PTFE fuel line is going to allow for enough movement between the frame hardline and the engine block (fuel pump)?

I'm thinking about ~4 inches of PTFE line. Is that enough to not stress the connection points or the PTFE line itself?

I have the hardline (steel) to AN connector already.


TIA!

[70STOVEBOLT]

As long as it’s not kinked you should be fine, it is flexible enough.

[Loose Screw]

Originally Posted by 70STOVEBOLT

As long as it’s not kinked you should be fine, it is flexible enough.

Yeah, this fancy fuel pump can be adjusted "clocked" to almost have the steel fuel line on the frame be a straight shot to the fuel pump connection with about 4" of PTFE line, it might be less taken the length of the AN connectors into account. I will try to leave some droop in the steel braided PTFE line for some movement (flex)...Thanks for your reply........

[MikeB]

I don't think you'll have a problem, but I'd put as much slack in the hose as possible. For example, can you make it a 6-in "S" or "C" instead of 4-in straight?

[Loose Screw]

Originally Posted by MikeB

I don't think you'll have a problem, but I'd put as much slack in the hose as possible. For example, can you make it a 6-in "S" or "C" instead of 4-in straight?

We'll see, right now I don't know how much the closeness of the frame to pump and the pliability of this steel braided Teflon line is going to be a factor in getting some slack.

[LS short box]

I've used -6 PTFE and rubber lined -6 for fuel lines. IMO the -6 rubber lined is a bit more flexible than -6 PTFE and is a bit cheaper for the line and fittings.
I do find the PTFE line is a bit easier to assemble.

[Loose Screw]

Originally Posted by LS short box

I've used -6 PTFE and rubber lined -6 for fuel lines. IMO the -6 rubber lined is a bit more flexible than -6 PTFE and is a bit cheaper for the line and fittings.
I do find the PTFE line is a bit easier to assemble.

Yeah, This is my first go round with AN PTFE but I'm so done with gummy rubber fuel line and it's "permeability"! It took me Years to come to My Own realization! My truck ain't no Cars and Coffee trophy winner but if I'm going to Have To do a job myself I'm going to try and do it a better way...

And I know there are the steel line craftsmen on here, but what are They using for "jumpers"

Damn, and I bought this truck to be Yard Art......

[LS short box]

What do you mean by "jumpers".

[Loose Screw]

Originally Posted by LS short box

What do you mean by "jumpers".

As per Google...

The flexible piece of fuel line connecting the rigid fuel pipes on the vehicle's frame (chassis) to the engine block or fuel pump is generally referred to as a flexible fuel hose, fuel feed hose, or fuel jumper hose.

[LS short box]

Learn something new everyday. LOL.

[A1971Blazer]

I used the PTFE lines from the hard lines to the tank and to the engine.
They are significantly longer than 4" and I left plenty of slack at the tank in the event that I would need to drop it out for some reason.

[Steeveedee]

Originally Posted by Loose Screw

Yeah, This is my first go round with AN PTFE but I'm so done with gummy rubber fuel line and it's "permeability"! It took me Years to come to My Own realization! My truck ain't no Cars and Coffee trophy winner but if I'm going to Have To do a job myself I'm going to try and do it a better way...

And I know there are the steel line craftsmen on here, but what are They using for "jumpers"

Damn, and I bought this truck to be Yard Art......

I started mechanic work in the '60s, and never heard the term "jumper". It fits, though I'd say someone made it up somewhere along the line. It isn't in any manual I've ever read, but I'm open to being educated. I wouldn't use anything but flexible line due to the vibration of the engine.

[binford]

I used the Aeroquip PTFE lines on everything.
Fuel, transmission and power steering (hydro boost)
It rated for 3,000 psi. LS swap

With 4" you won't have any room to have a bend in it .i.e S shape

But it is flexable.

Tip: Use some transmission oil on the parts when putting it together.
I use black electrical tape on the section I'm cutting and cut through the tape, with my cutoff wheel.
Clean the bur's from the teflon inner tube with a new razor blade.
Push just a bit of the ss flex back enough to get the brass part inserted.
Oh don't forget to put the fitting on the hose first.
I'm sure there is a youtube video out there. They are a pain to put together the first time or two.


Like you after having to replace fuel hoses every 7 years or so, I just ponied up and got the good stuff. I saw a guys truck 67-72 on fire on the side of the freeway. I did not want that to happen to me

[70STOVEBOLT]

I was just reading about this PTFE fuel hose. It appears the widely available 6AN hose is only 5/16 ID, not 3/8. Is this sufficient for a mild big block in a long length?

[Steeveedee]

I don't know about a mild big block, but when I'm towing my 6000 Lb trailer up a long hill at 65 MPH in the heat, that 1/4" tubing from an auxiliary fuel tank doesn't seem to be a fuel starvation issue. And the nipple on that fuel tank has about a 1/8" ID. I'd be concerned if I was drag racing, though.

[57taskforce]

I just ran new PTFE lines to replace the rubber sections on my 1998 Big block K2500. I’ve done a lot of AN work in the past but this was my first time using PTFE. Make sure you get the right fittings. Regular braided rubber hose uses different fittings than braided PTFE hose does. I’d suggest going with tube to AN fittings to connect to the factory frame side hard lines. I wouldn’t use hose clamps to connect to the PTFE to the hard lines like the factory did with the rubber. The fuel systems on these trucks are low pressure enough that It shouldn’t matter but be aware that different brand fittings have different pressure ratings. Something to pay attention too depending on what you are working with. Also you don’t necessarily always have to tighten the hose side of the fitting down all the way to get it to seal. Sometimes it works out depending on your hose and brand of fittings where it may not tighten down all the way to the teflon portion part of the fitting, and that’s ok.

Here’s my recent work. I bet these notoriously leaky hoses don’t leak ever again, at least from the hose portion.
I would definitely leave more slack than 4” in your situation, you need the ability to get everything happy when you put it all together.

[MikeB]

I've had at least three Chevys over the years that came from the factory with a base V-8 and 2-bbl carb. All of them had 5/16" hard lines and hoses.

Later on, two of them got 350 engines, and one a 383. All had 4bbl carbs and dual exhausts, and I'd categorize them as mild-mid performance.

But I never had a problem using the stock 5/16" OD hard line and 5/16" ID hose on any of those vehicles.

Here's something strange: An 82 C10 I had for a while came with a factory installed 250 six, but it used a 3/8" fuel line and a 1/4" return line between tank and pump. Go figure.

[Loose Screw]

The Day Has Come after 6 months of *****footen around.
Wish me Luck Boys!

[Loose Screw]

Oh, and one more question!
Do I Use TEFLON TAPE when I make any Threaded Connections?

Thanks!

[A1971Blazer]

Originally Posted by Loose Screw

Oh, and one more question!
Do I Use TEFLON TAPE when I make any Threaded Connections?

Thanks!

only if it's an NPT threaded fitting.
The AN are tapers self-sealing fittings.

[Loose Screw]

Originally Posted by A1971Blazer

only if it's an NPT threaded fitting.
The AN are tapers self-sealing fittings.

Understand, Thank You!

On yours did you use white or yellow tape?

Again Thanks....

[Loose Screw]

Img_1976 (1).jpg

[A1971Blazer]

Originally Posted by Loose Screw

Understand, Thank You!

On yours did you use white or yellow tape?

Again Thanks....

I use yellow but either will work, just make sure not to wrap any into or over the hole. It can get into the system.

[LS short box]

So here's how I do PTFE -6. Figure out the length you will need. I wrap the hose with black electrical tape to reduce the stainless from fraying and then clamp the hose in my vise. I use a very fine tooth hack saw blade to cut the hose in the middle of the black tape. Some use a cutter like shown in the pic above.
I clean up the frayed SS ends as needed with side cutter. Then I slide both "nuts" over the line.
After that I take a small flat screw driver and spread the SS covering away from the teflon liner just enough to make it easy to slide the brass "olive" onto the teflon liner. The olive has small step on the inside. Slide it on the telfon until hits the step. Then I take a center punch and into the liner to kind of spread the liner against the olive making easier to slide the fitting in. And as said above a bit of lube will make sliding in the fitting a bit easier.
One more thing in regards to the orientation of the fittings. Once you tighten the fittings they can't be rotated like some rubber lined -6 fittings. Figure out the orientation of the fittings on both ends of the line and mark them before tightening.
I never had a -6 line teflon or -6 rubber lined fail.

[Loose Screw]

I'm at the frame hard line right now. The original steel fuel line end is 'pumpkined' (Not flared), like an affixed pumpkin, bulge in the middle and kind of coned at the end. The brass pumpkin that came with the AN fitting does fit over that bulge and is pretty loose on that steel fuel line. It would take some torqueing to get that brass fitting to choke down around that steel tube...*Maybe, I could connect /seal off with the steel pumpkin end that's affixed to the line already?

Should I use both?