First off is to go over all the tools and materials and where I found them. You’re going to need a good tubing bender and the best one I found was this one at Eastwood.Tube Bender From Eastwood They’ve got two different sizes and you’ll probably want them both if you like the hard line look. The smaller one does brake lines and the larger one will do all your oil lines. The great thing about these tools is the fact that they have a roller follower that rolls along the tubing instead of sliding on it like most conventional benders on the market. The other types will work fine but I figured since I was buying a set, I might as well buy these.
Along with a good bender you’re going to need a good flaring tool. Now pay particular attention to this. The type of flare used on your brake lines is an AN 37° flare. While you might think that your 45° flaring kit that you can get down at AutoZone should work cause it’s only 8° difference, you’ll be sorry later down the road when you plow in to grandma’s Buick. The AN 37° flare was developed for the military where constant servicing, tear down and reassembly are required. Our friends at Motown stick with the SAE 45° flare because it works good for the semi-permanent application of production automobile manufacture, where once assembled it usually stays that way for the life of the vehicle.
I found my flaring tool after quite a bit of searching around town. You’d be surprised to find out how many people have never heard of the AN 37° flare. I chose the RIGID P.N. 41162 tool Rigid Flare Tool. It cost me about a C-note but it is definitely one fine piece of equipment. It’ll do all the sizes of tube I’ll ever be flaring and it has this neat torque limit feature that clicks at the end of the flare pulling the cone up just a tad to burnish the flare for about three more revolutions and then stops. This makes for very consistent flares for your whole system.
Next are the fittings for the connection. All of your banjo fittings come set up to use AN-3 connections. So what you’ll need are some tube nuts and sleeves for 3/16” tubing. These were a real mother to locate last minute for one of my buddy’s build projects a couple of weeks ago. But this place I found on the net has everything you could dream of for doing this type of work and for a pretty decent price. http://www.anplumbing.com Go to Section: Adapters-Stainless Steel and look for P.N.s818-3j (3/16 tube nut) 819-3j (3/16 tube sleeve). You’ll need one of each for each connection. Also check out the other fittings they’ve got, You might find something you could use.
The final item you will need is some good quality seamless 3/16” SS tubing. You must use seamless tubing if you are going to flare it. Welded tubing is considerably cheaper but the weld seam will crack when flared thus rendering it useless. I acquired mine from Seamless Tubing – McMaster.com. (Seamless Tubing 304SS 3/16” O.D. .028” wall thickness P.N. 89895K716) It’s about $30 a six foot stick. Mcmaster ships quickly and packages the tubing very well for shipping. It probably wouldn’t be too hard to find it locally but you have to make sure they don’t slip in the welded type of tubing on ya, Seamless, Seamless, Seamless! Another thing to make sure you do is to cut the tubing properly with a cutoff wheel and not a tubing cutter. A tubing cutter will work harden the tubing right where you’re going to flare it resulting in possible cracking during the flaring process. Make sure you deburr the cut with a small round file or rotary tool. Any burr or lip left from the cutoff wheel will get folded into the flare by the rolling cone on the flaring tool and your connection WILL leak. I know this from experience.
Now you’re ready to start plumbing! Take some time to look you ride over and find the right line for your new brake lines. If you’re on a rigid frame, the rear line will be quite easy as there won’t need to be any flexing of the line due to suspension movement. One thing you will need to take into account is adjusting your chain or belt. I left a Z bend in my rear line to accommodate chain adjustment.
If you have a swing arm frame you will need to find a point to use a flexible jumper line. Be creative and you can hide it quite well. For the front line you have two options for handling the travel in your front end. You can run the hard line from the handle bar MC all the way down to right above the slider and run a jumper to your front caliper like the one shown below.
Your other option is to plumb back from your caliper with hard line and have a slider clamp at your lower tree where the rest of the way is run with flex line. I’ve seen this method done on some of Jerry Covingtons long bikes but my personal preference is the first method.
Now the moment you’ve all been waiting for, making the actual flare. After your line is laid out and bent to the desired form it’s time to flare those ends. Place the properly deburred tube end in the flaring tool with the end of the tube flush with the Die block.
Make sure you put your sleeve and nut on before you start flaring or you’ll be starting over. This brings me to another point, when you start out running these lines you might want to make a few practice runs using some cheap plain steel tubing to get it just right. It really hurts to throw away 3-4 feet of tubing that you paid $5 a foot for. Now you’re ready to start running in the flaring cone. Just hold the die block and start turning the handle clockwise. You’ll notice the handle building up some resistance and then it will “click”. Keep turning the handle as now you are burnishing the flare. It takes about three more turns and then you can back the cone off the flare and remove it from the die block. Now you should have a nice flared end that looks like this.
Here is a shot of what the complete connection of an AN-3 connection looks like in it’s unassembled form. Note that I have shown a double male 37° nipple that you will need when connecting your tubing to a pre made soft brake line from someone like Goodridge.
And here is the whole assembled connection. While this method of running bake line may not be the easiest it is by far the most appealing to the eye.
The tubing is much smaller than a conventional soft line and when it’s all polished you can’t beat it. This is definitely one of those do it yourself projects that when mastered will give you a look that is unmatched in cleanliness and detail. Good luck and keep it hard!
