By Jim Smart
Classic Tube makes it easy to make your own Fuel and brake lines. Classic Tube offers rolls of steel, stainless steel, and aluminum tubing you can custom bend and flare to your liking. This makes perfect sense if you’re restoring an obscure muscle car for which Classic Tube may not stock prebent lines. You also have the option of shipping your existing brake and fuel lines to Classic Tube, where they will be used as a template to make new lines. If you don’t have the old lines, you can send Classic Tube your specifications, and the company will bend and form lines to your blueprint.
Although the federal government can be a pain in the neck to automakers and individuals in terms of tougher safety and emission standards, it has contributed greatly to both vehicle safety and improved emission standards for the past half century. Much of it began with seat belts, padded dashboards, collapsible steering columns, impact absorbing crush zones, catalytic converters, and better braking systems.
“Brake lines are always double flared to contain extreme pressures”
There’s something so gratifying about fabricating replacement parts for your muscle car. It is the ultimate way to personalize your ride by doing something no one else has done the same way. Take tube bending and flaring for example. This is something you can do yourself in your home garage and feel good about your project when the job is done. The beauty of custom tube bending and flaring is being able to route brake and fuel lines where you want them or, as a matter of convenience, opt for prebent lines ready for a quick bolt-on you can do over a weekend. Classic Tube offers rolls of steel, stainless steel, and aluminum tubing you can custom bend and flare to your liking. This makes perfect sense if you’re restoring an obscure muscle car for which Classic Tube may not stock prebent lines. You also have the option of shipping your existing brake and fuel lines to Classic Tube, where they will be used as a template to make new lines. If you don’t have the old lines, you can send Classic Tube your specifications, and the company will bend and form lines to your blueprint.
Tube bending and flaring tools are available from a variety of sources, including Harbor Freight Tools and The Eastwood Company. The bending and flaring tools out there are designed to fit many budgets. We will show you a few and how to use them. When you are fabricating lines, it’s vital to take your time and get it right. Cockeyed and incomplete flares can cost you in time and leakage.
Stainless steel is harder than galvanized steel and thus more challenging. You can count on winding up with scrap stainless as you learn the ropes. Yet stainless virtually never corrodes and will outlast any other material, so the learning curve is worth it. Stainless has to be treated differently than conventional galvanized steel because it is a much harder material. Line ends must be completely free of burrs and imperfections. Some seasoned tube bending professionals suggest the use of a hacksaw instead of a tubing cutter, because a tubing cutter will work-harden stainless, making it tougher to get a proper flare. It is also virtually impossible to get a good double flare from stainless. Extra care must be taken when bending stainless.
We have been asked time and again what kind of flare to use for brake and fuel lines. In both cases you must have a double 45-degree flare, especially with brake lines, which are always double-flared to contain the extreme pressures that exist in a hydraulic braking system. AN fittings get a 37-degree flare. When you slam on the brakes, your master cylinder is applying on the order of 1,800 psi to the lines, fittings, calipers, and wheel cylinders. It is mandatory for you to apply a double flare to every line end and fitting.
When you are flaring brake and fuel lines, it is suggested you use a lubricant at the flaring head and line end. This makes the going smoother when you are flaring the tip. For brake lines, use brake fluid as a lubricant. For fuel lines, use a low-viscosity engine oil or even WD-40 as a flaring lubricant. Power steering lines get power steering or automatic transmission fluid as a lubricant. In short, use a lubricant compatible with the medium your lines will carry.
1. The industry offers an extensive lineup of tube bending and flaring tools. Double-flaring tools are available for $12 to $22 from Harbor Freight Tools. Opt for the higher-priced tools when you can because you generally get what you pay for. The multiheaded flaring tool on the left is quite expensive. However, if you do a lot of line fabrication, especially in stainless steel, it is a good investment.
2. On the left is a completed fuel line double flare. On the right is a brake line with a bubble flare, not yet completed to a double 45-degree flare. There are two steps to flaring. The first step is this bubble flare. The second is when we roll the sides over into a double flare like you see on the left.
3. If you’re thinking about using a hacksaw or cutting disc to cut your lines, here’s a more civilized approach (unless you’re working with stainless steel tubing). A tubing cutter gently cuts into the line as shown. Slowly increase pressure on the disc and line rotating the cutter in a back and forth motion for 360 degrees until the line severs.
4. Tubing cutters enable you to clean the inside diameter as shown prior to tube flaring. You want to remove all ragged edges before flaring begins
5. Finish the tube ends as shown with 240grit sandpaper to achieve a smooth flare.
6. Measure twice, cut once. Allow yourself enough length, which includes bends, before cutting. You can use coat hanger wire as a template between connections (much as exhaust shops do) to prevent wasting expensive tubing.
7. Tube bending begins with lining up the reference mark at zero and bending from that mark.
8. Slowly bend the line as shown to the number of degrees desired. Do a fit check and bend more if necessary.
9. Prior to starting a flare, line ends should be clean cut like this one, free of burrs and other irregularities.
10. The average muscle car home garage isn’t going to need this professional-grade multiheaded flaring tool. However, if you’re going to do a lot of flaring or outfitting your ride with stainless tubing, the pro flaring tool is a must. We’re going to show you how to use it.
11. First order of business in flaring is to use the proper die. This die executes the initial bubble flare where the first wall of a double 45-degree flare gets rolled inward
12. This is the initial bubble flare created by the first 3/8inch die, which sets the walls up for 45-degree roll-in.
13. The second die rolls the walls into a 45-degree flare where the double-flare looks like this. You should have a perfect 360-degree flare. Any irregularities are unacceptable.
14. Budget tubing benders will get the job done if cash is tight.
15. This is a budget line flaring tool from Harbor Freight Tools. Set up the flare by extending the line the width of the die.
16. The bubble flare is performed first. This step performs that initial roll-in.
17. Walls are rolled over and ultimately in to create the 45-degree double flare.
18. The final die rolls the bubble flare inward to produce the 45-degree double flare mandatory for brake and fuel lines.
“Extra care must be taken when bending stainless”
19. It is easy to forget to install the line fitting before doing the flare. Line fitting first, then flare.
20. On a really tight budget? Use a large socket for your tube bending. It works. In fact, a socket can perform bends a tubing bender cannot.
21. Look what custom tube bending from Classic Tube did for this Ford 390.
22. Tube bending can be performed on the vehicle with a “bend as you go” approach.
23. You may use steel or Adel clamps for line security. The advantage of a rubber-lined Adel clamp is the elimination of chafing from vibration.