Mk1 under-car fuel line diameter

[burn_your_money]

My steel lines under the car sprung a leak and I'm going to have to replace them. They are leaking pretty good. The car was recently undercoated so if anyone can save me the trouble and tell me their outside diameter it would be greatly appreciated. These are the steel lines that run from the tank to the fuel filter.

84 Jetta diesel

[theman53]

I don't know for sure but I think they are 8mm? Turbo J had this discussion a while back and wanted to go bigger so you may find them there.

I know my MK2 lines are plastic not steel, I never melted my MK1 lines to know the difference.

[ORCoaster]

Ran out to the car and just below the fuel filter the hoses go to the steel lines.  Looks closer to 5/16 than 1/4.  Didn't have my calipers handy.  Those on the workbench 225 miles away.

[RustyCaddy]

replaced the steel feed line on a caddy with aluminum 5/16ths a while back...the size was recommended by Justin at Greaseworks and it was very close to the metric size

[burn_your_money]

Wonderful. You guys are awesome, thanks

[CRSMP5]

i use 5/16th copper... never rust again.. easy to bend so on..

[8v-of-fury]

Doesn't copper react all weird with diesel? Plus just because it doesn't rust does not mean it doesn't corrode just the same..

[burn_your_money]

I'll probably go with coated steel, or maybe aluminum.

One more thing, does anyone know how many feet of the stuff I'll need? I would think a 25' roll would be plenty.

[8v-of-fury]

I once ran a sub woofers power wires under the car, and they took basically the same route as the fuel lines, but on the ohther side of the car. 12ft was just just just enough to reach from battery to trunk.. so basically the same as tank to engine bay.. I'd say 30 to be safe.

[ORCoaster]

I think you would be good with 25 feet.  Run from fire wall to tank is much shorter than battery to rear of car.  I would run one line from tank to filter and then with what is left bring it as far to the front as it will go.  If it doesn't get to the filter run hose down to it from the filter.  That would be cheaper than trying to get a splice in there with a compression fitting. 

Rolls of tubing are weird at that 25 foot length. 

[theman53]

Doesn't copper react all weird with diesel? Plus just because it doesn't rust does not mean it doesn't corrode just the same..

I use the NiCu brake line, copper plated nickel. I don't believe it reacts to anything. And all it does is patina which is tarnish. So it turns green and that is it. It is about 40.00 for a roll of 3/16 ... more than double the steel stuff, but you never replace it again.

40 locally but of couse ebay http://www.ebay.com/itm/Copper-Brake-Line-Tubing-Coil-3-16-x-25-Roll-/280867343070?pt=Motors_Car_Truck_Parts_Accessories&hash=item4164ff8ade&vxp=mtr

[rs899]

I need to do this too on the Jetta.  It's leaking somewhere where it goes into the frame right behind the filter.

I was just going to use 3/16 steel brake line (FLorida- no real rust here).

So , is 3/16s big enough "the man53 "?  Don't really want to go bigger if I don't need to- Probably harder to bend as it gets bigger.

[theman53]

3/16 is my brake line NOT fuel line. 8mm or 5/16 or bigger would be fuel line.

[maxfax]

I use the NiCu brake line, copper plated nickel. I don't believe it reacts to anything. And all it does is patina which is tarnish. So it turns green and that is it. It is about 40.00 for a roll of 3/16 ... more than double the steel stuff, but you never replace it again.

Acidic stuff doesn't seem to phase the stuff too much.. I used it for my WVO getup.. It took YEARS to even show any sign of tarnish.. 

Icing on the cake, it bends and flares like soft copper tubing, yet doesn't crush easily...  Well worth the money for the hassle saved..

[burn_your_money]

Just an update, it was 8mm and 20 feet would likely have been enough. I bought a 25' roll at Canadian tire. It was suppose to be $1.50/foot but when the cashier scanned in the roll it came up at $1.50
I used steel line and you do need a bender to bend it without kinking it.