Wednesday, January 12, 2011

Safely Making a Double Flare

The article featured on this page is from the February 2011 issue of Auto Enthusiast Magazine.

A Flaring Situation

Doubling the safety on a custom fitted hard line

Story Earl Duty

When it comes to cutting a brake line and re-flaring that severed connection, a double flare is the only safe option. Is creating a workable double flare, in your garage at home easy? Sure it is … with the proper tools.

Buy a cheap kit and it will make your life miserable, not to mention it could create a safety hazard. Our goal is to demonstrate the proper way to double flare a brake line.

Our project started by doing some research for an inexpensive quality flaring kit. As we all know, word of mouth is good advertisement. By asking friends in the business, more than once service kits came up as a workable and inexpensive option. This kit not only offered everything needed to create a double flare, it included a mini tubing cutter and a tubing bender for making those curved bends without putting a kink in the line.

After getting our kit and briefly going over the supplied instructions, our work began by clamping the holding bar into our bench vise. Next, we measured off the length of brake line needed and cut the 3/16-inch tube using the supplied mini tubing cutter. After cutting any thin-wall steel tube, the cutting procedure will force the metal inward and leave material that must be removed. And that’s where the supplied deburring tool came in handy. After deburring the metal, it is critical that any and all metal shavings be removed with compressed air. Safety glasses are required when using compressed air.

With the brake line now ready for us to start the flaring process, we installed the tube into the holding bar and set its height adjustment using the appropriate flaring adapter as a guide [see image #4]. Our adjustment is now set, the thumb screws tightened on the holding bar, and it’s time to move on to the next step, which is to add a touch of white lithium grease to the flaring adapter. After lubricating the adapter, we inserted it into the opening of the tube with the pintle pointing down [see image #5].

Next, the yoke is installed over the holding bar so that the tapered swivel is resting into the depression in the adapter. From there, we cranked the turning bar clockwise until the adapter was flush with the holding bar. This procedure created a bubble of sorts on the end of our tube. The final step was to simply remove the yoke and the 3/16-inch adapter, reinstall the yoke and crank the tapered swivel into the bubble opening until it came to a stop. Presto … a perfect double flare the first time. No muss, no fuss.

1 We begin our project by clamping the holding bar in the bench vise. After determining the exact length of 3/16-inch brake tube to remove, the mini tubing cutter [supplied with the kit] was used to perform the amputation.

2 After the cut, excess metal must be removed with the supplied deburring tool. The deburring tool has sharp blades for easy removal of the metal.

3 The finished cut must be clean and even. We used compressed air to blow any metal chips out of the tube. Caution: Wear safety goggles when using compressed air! Before proceeding to the next step, make sure the ferrule nut is in place and pointed in the right direction.

4 We then placed the proper flaring adapter [in our case, 3/16-inch] upside down on the holding bar and adjusted the tube to the length equal to the flat on the flaring adapter. Just prior to flipping the flaring adapter over for the next step, a small amount of white lithium grease was applied to the adapter’s surface.

5 The adapter, with the pintle pointed down, was then installed onto the tubing.

6 Our yoke is then installed and positioned to where the swivel enters the depression formed into the adapter.

7 By turning the yoke handle clockwise and compressing the metal inward with the adapter until it bottoms out, the finished job should appear as a formed bubble, with the hole centrally located. If the hole were to be excessively off center, it would be necessary to start over.

8 The yoke was then reinstalled. The swivel was cranked down until the metal folded in on itself and our swivel bottomed out.

9 A correct double flare will appear like this.

10 Compare the factory double flare (right) to our double flare (left inset). See any difference? There is no difference, and that’s what we set out to accomplish. The kit works, and created this double flare on the first attempt.

11 Also supplied with the kit was this handy tubing bender. This bender makes a nice, clean, sharp bend on tubes without putting a kink in the metal.