So I have endeavored to replace the fuel lines in my Fiero and to upgrade them with AN lines and fittings. Also to route them better than the factory did. I have a V8 in el ferrero and would hate to see my car burn down. Fist off I had -6 AN fittings brazed onto the fuel lines that run out the back of the tank. From there I am going to use 1 foot braided line to hard lines mounted to engine bay. From there it will go braided again until it meets the engine. I have found bits and pieces of information on the internet but no definitive information on 3/8 fuel lines, this guide is designed help people bending this tubing. I would like to share with you what I have learned since I have started this adventure.

Lesson 1: 3/8 steel tubing is far more difficult than1/4 tubing!
Lesson 2: Buy a tubing bender, you will need it! (Harbor Freight will do)
Lesson 3: A vise is pretty much a requirement.
Lesson 4: Vice grips on the tubing to ensure the tubing does not pull into the bender are crucial for astatically perfect bends. I put a hand towel over the line and then apply the vice grips.
Lesson 5: Go to pet smart and get your self some fine sand. I checked at Lowes and they did not have fine enough sand. Cap one end, fill with sand, pack sand, fill to brim and cap other end. This seriously helps, it keeps the line from collapsing when pulling 90 plus deg. bends.
Lesson 6: If you do go past90 deg and the tube after bending you notice it has collapsed a bit you can take a small hammer and try to bend it back into more of a round shape. The sand really helps keep the correct shape with this too.
Lesson 7: Pre bend a piece of copper line to the shape that you want to bend using the same radiuses as you will put into the larger line. Then use it as a template for the steel line. This will save you time, money and most importantly frustration!

I am going to post pictures of the entire project, so please reply back with areas that you would like to see. Thank you.

I would like to see the bender you have been using. I bend 3/8" steel fuel lines quite frequently and never had any issues.

I've never had to pack sand in my bender either, and it's never linked.

I like to use coat hangers to mock up my bends before bending tube.

i have had good luck with this style bender...no kinked tubes yet...

I use the same one as black88fiero never had any problem....No vicegrips, No sand, Just the bender...

[This message has been edited by 88lambo (edited 04-01-2011).]

quote Originally posted by 88lambo: I use the same one as black88fiero never had any problem....No vicegrips, No sand, Just the bender...

Same here...

Maybe he is using steel pipe and not tubing?

Those benders aren't all that good. I've had some issues with them, the bend radius is too sharp for 3/8" with the quality of the tool being as it is. They are kind of a knock off design based on:


This one will knock out a 180 bend without collapsing anything.
But, for the price, the cheep one might get the job done, and it will do it fairly well on 1/4" and 5/16" because the ratio of bend radius to tube diameter is greater. I went out of my way to get the expensive one in 3/8" and 1/2". It'll do stainless comfortably.

I was reading that thinking... I bent 3/8" tubing all the time working at the machine shop and didn't have to go through all that to do it. I think alot deals with the type of bender and how tight your trying to make the radius.

quote Originally posted by Fierobsessed:

That's the style we had at the shop, and I've used the HF one above, but not on 3/8" yet.

[This message has been edited by Khw (edited 04-02-2011).]

quote Originally posted by Fierobsessed: Those benders aren't all that good. I've had some issues with them, the bend radius is too sharp for 3/8" with the quality of the tool being as it is. They are kind of a knock off design based on: This one will knock out a 180 bend without collapsing anything. But, for the price, the cheep one might get the job done, and it will do it fairly well on 1/4" and 5/16" because the ratio of bend radius to tube diameter is greater. I went out of my way to get the expensive one in 3/8" and 1/2". It'll do stainless comfortably.

I agree, the cheap $8 bender from Harbor Freight is not the best one out there. But for the amount of use I needed one for, it got the job dun just fine... That one you posted looks like it would cost 3-4 times more? And if it sayd SnapOn somewhere on it, it prolly costs as much as my Fiero

Looks like $50 for the one that does 3/8", $100 for the one that does 1/2".. Ridgid 404 and 408 tubing benders, respectively..

I bought a quality Ridgid pipe flare tool (the heavy cast iron one with a screw that clamps the 2 halves together @ the flare point), and it's GREAT. Much better than the $10 cheapy ones. I have the $10 knock-off tubing bender, I should spend the $50 for that Ridgid one if I ever get back to working on the car. I had covered my steel tubing with adhesive-lined heat shrink before bending, and the cheap bender didn't do too well on it.

So the first post in this article describes how I made the bends. My results are in the pics below. There are other ways to ben these lines, but if you are going for perfection and are running two lines paralell it takes very tight and accurate bends. Hence the methods I used and the results that I got. They are full flow even in the bends that are well beyond 90 Degreese in 3/8 tubing. I hope this helps anyone out there that is thinking of replacing the stock lines with something that is lifelong and built for flow. I tried to find articles even outside of the fiero scope on the internet and came up with very little results that were what I was looking for. Thank you guys for enjoying the same passion that I do.