Fuel Lines

[spursfan55]

Is it possible to use metal brake lines for the fuel lines running from the tank to the engine? I need to replace them because they are rusty.

Any help would be good.

[DatsunZsRule]

I'd replace them with the proper fuel lines. My 2 cents.

[Matches]

What is the difference between the metal fuel lines and metal brake lines? Its just a steel tube right?

[JimmyZ]

Good luck finding 1/4" lines if you can. I think I saw a 25ft spool of 1/4 galvanized line at a "real" parts store. If so, it would be fine. Shy away from anything small for the supply line such as the 3/16" commonly used for brake lines. Debur the ends when cut and use the proper bender for smooth radii. In time the ends that you cut may rust but that's a long way down the road.

If you want ot get fancy then stainless...

http://www.eagletube.com/

The reason 1/4" is less common is that 3/16 is a good balance for brake lines. It will move enough fluid and has less surface area for expansion. (Tubing expands under pressure) If you make a brake system with 1/4" lines you can actually feel the diff in the pedal.

Read up on vapor lock and you'll see why fuel supply lines need to be large and as straight as possible. Copying the stock system with the same size tubing is fine too.

[JimmyZ]

http://www.eastwoodco.com/jump.jsp?itemID=16272&itemType=PRODUCT

$99 from easwood!

The normal galv line is 1/3 that. (Also avail for eastwood)

[Walter Moore]

Is it possible to use metal brake lines for the fuel lines running from the tank to the engine? I need to replace them because they are rusty.

Any help would be good.

The short answer is yes, it is possible.

There are four steel lines that run from the engine compartment to the back of the car. They all run down the right side of the transmission tunnel.

I replaced these steels tubes with universal brake line that I bought at a local auto parts store. (I went to Advance Auto, but NAPA may have a better selection.

The steel lines that I used, measured by outside diameter were:

Fuel delivery: 5/16"

Gas tank vent: 1/4"

Fuel return: 3/16"

Rear Brake: 3/16"

Those are the sizes that I thought were the closest to the original diameters.

From a generic parts store they only come in straight, 6 foot sections, and I had trouble buying couplings for the big lines. Seems to me that I had to go to an actual hydraulics supply house to get them.

(Or was I fixated on using flair to flair fittings? I can't remember. Compression fittings might work just as well.)

Remember that the actual brake line requires those special 10mm Japanese fittings.

To actually access these lines in order to replace them I had to remove the entire drive line, engine to differential. All four lines are held together in a single bundle, so I doubt that it would be worth the effort to replace only the fuel lines. You would certainly end up breaking the others off.

If you search the forums you will find several threads on companies that provide preformed lines that more or less exactly formed for this purpose. It took HOURS to bend these lines by hand, and then days to carefully route them so that I could reattach the retaining hardware.

(Or at least it seemed like days... I don't like spending that much time laying under a car supported on jack stands.)

By the way, if you do decide to do this by hand, buy a GOOD (expensive) tubing bender for the 5/16" line that will guide and contain the tubing while it is bending. That stuff is nearly impossible to bend with a cheap open type bender. We kinked several pieces before we discovered that you can use a table top to backup the bender.

So yes, I did replace my fuel lines with universal brake tubing, and it works fine. But unless you are a master with a tubing bender don't expect it to be easy, or look very nice.

[dkd021]

Having just finished this last night, I can attest that it is no fun. It took me a few months to get it right. Personally, I'd buy a parts car. Unless you're absolutely certain of the routing of the lines, I'd take a ton, & I mean DOZENS of pictures. I took a few but it never sufficed. I had to look at my parts car.

The other thing is that if you're going to remove them, remove everything first as stated by Walter. Don't think, "I can get by without removing the rear end, driveline, & transmission" because it's a frustrating job. You want all the room you can get. You could just drop the rear end & not remove it but I'd just go the little bit extra & take it out.

Properly lube the 7mm bolts before trying to remove them from the bracket. Be patient. Don't let them break. It happened to me on one. It's no fun tapping a hole while underneath the car. Be patient removing the rubber/now cement insulators. Don't let them chip or break if possible. I soaked them for a couple of weeks in some engine stop-leak. I left them out for a couple of days to dry off & they were pretty pliable for several days.

Have someone help you as well. I can speak from experience that this is not a one person job. So basically, in my opinion, find a junker & remove the drivetrain & parking brake. Take a couple of days lubing the bolts & insulators while removing the lines. Then do the opposite to install them.