Bending Stainless Steel Tubing - Bend Your Own Brake Lines

Inexpensive double-flaring kits like this one can be purchased for less than 40 bucks and can handle 31/416-, 11/44-, 51/416-, 31/48-, and 11/42-inch tubing diameters. We've used this KD Tools setup hundreds of times over the past decade.

Though cheap tubing cutters are available, they don't have proper handles and require extra twisting effort to make cuts. This used one cost us $10 at a swap meet. Its long handle and knob adjuster make cutting a breeze. Watch out for inferior metallurgy on cheap imports. Even thin-wall steel tubing can chip and dull their cutting wheels. They don't last long.

Our tubing cutter has a flip-out reamer to scrape out the ridges. In a pinch, you can also use a square file or just about any paring knife as long as it fits and is harder than the tubing material. Just remember to stick it back in the kitchen before anybody notices it's missing.

Before the tube is clamped by the jaws of the flaring bar, the 11/48-inch-thick heel of the flaring adapter (shown) is used to establish the 11/48 inch of tube that protrudes beyond the bar. This is a critical step. Too much tube will cause the flare to collapse or become cocked off center. Insufficient protrusion yields an incomplete flare (junk). Use the heel of the appropriate-size adapter as your guide and you won't go wrong.

The pressure from the yoke's pointed swivel and flaring adapter against the flaring bar forms the tube end into a bell shape. You're halfway done at this point.

Once the flaring bar is clamped tightly around the tube, the stem of the proper size flaring adapter is inserted into the tube as shown. Notice the tapered openings of the flaring bar that support the tubing and help form the needed taper. The other side of the bar has hard, 90-degree openings with no taper. That's the wrong side, don't use it.

To complete the double-flaring operation, the pointed swivel end of the yoke is inserted into the tube and tightened again-this time without the flaring adapter in place. This step folds the metal in on itself.

After reaming, the tube on the left is opened up to its full diameter, but there is still an irregular edge at the end of the tube that has to go.

Freshly cut, notice the ridges of displaced tubing left inside the tubes. These must be removed.

The resulting double flare is much stronger-and safer-than a single flare. Single-flare tube ends are made by eliminating the flaring adapter steps and using only the yoke to press the tube end into a Y-shape. Single-flare tube ends tend to crack and have no place on the street or strip.

Position the yoke onto the flaring bar, trapping the flaring adapter, and start twisting the screw all the way until it stops. A drop of oil on all friction surfaces prolongs tool life.

Careful use of a flat file eliminates the roughness and creates a chamfered edge around the tube opening. It doesn't take much effort, but don't go too far and file an angled surface onto the end of the tube. It needs to be flat.

Benoit took his time while carefully marking the new 11/44-inch brake lines where they needed to be bent for best routing. Aesthetics and function are of equal concern.

After one line is finished and successfully test-fitted, a second line can be made using it as a model. As with flaring operations, make sure the needed threaded fittings are in place on the ends of the tube before bending or it's all a waste of time.

The finished job looks great and allows plenty of clearance for valve-cover removal. The factory locating clips are even reused to eliminate vibration and restore that OE look everyone's clamoring for.

Flaring is only half the battle when it comes to automotive plumbing using thin-wall steel tubing. You also need to bend the tubing to fit the car. Sure, you can bend it by hand, but the result always looks amateurish, and you're just asking for kinks. Single-size bending tools (bottom) are cheap, but you'll need to buy several to suit various tubing diameters. The spool-type tube bender (center) is better and fits multiple tube diameters. The articulated bender (top) is our favorite, as it helps eliminate guesswork for professional-looking results.

Where access allows, the lines are bent in place for less chance of confusion and accidental screw-ups. When the bender won't fit, the line is marked and the needed bends are performed on the bench.

Putting theory into practice on the groovy CC/Rambler, note how the stock brake lines are scruffy looking against the freshly detailed engine bay. Worse, their routing interferes directly with valve-cover removal. Something must be done.