I would suggest using the
copper-nickel alloy brake line as it is easier to work with than your standard
stainless steel. On top of that, this alloy allows for much better double flares.
You can technically flare brake lines while they’re in the car. However, you might find it difficult unless you either have a helping hand or a small vise of some sort.
That being said, let’s get started with the tutorial section of this guide.
.Step 1 – Cut the Lines – The first thing you’ll want to do is measure your lines, and cut them down to length. To cut the lines, tighten down the line cutting tool at a location where you want to make the cut, spin the cutter around the line. Once it’s no longer offering resistance, tighten the tool some more and spin it around the line again. Repeat the process until the cut is complete.
- Step 2 – Clean up the Cut – If there’s one thing that’s often overlooked when flaring brake lines, it’s cleaning up the cut. There will always be burs or uneven edges at the place where you’ve just used your cutting tool. Mount the line into a vise and file it until you’re left with a clean, smooth crown. Additionally, take a box cutter or a knife with a similar edge and run it around the inside of the line. Doing so will scrape off any debris.
- Step 3 – Set Up the Brake Flaring Tool – With the line cut and prepped, set up your flaring tool inside a vise. Make sure only to grip one part of the tool since it’s made of two moving parts. Apply just enough pressure to keep the tool in place.
- Step 4 – Apply the Hardware – Sliding the hardware on the line BEFORE flaring is probably one of the most common mistakes people make when flaring. Make sure that you have your hardware on those lines before moving forward. Otherwise, your perfect double flare is going to end up in the trash.
- Step 5 – Clamp the Line with the Tool – The next step is to place the brake line into the adequate slot on the tool, ensuring that it is visually sitting at the same height as the insert you’ll use to flare the line. Once you’re sure it’s sitting even, clamp the tool down.
- Step 5.5 – Lubricate the Line – Use brake fluid or brake fluid safe grease to lubricate the portion of the line that is about to be turned into a double flare. You don’t have to go overboard with the amount of lubricant. A little will do. Also, don’t use silicone-based lubricants as they are not safe to use on braking components.
- Step 6 – Flare the Line – Insert the flaring insert into the brake line and install the guide tube over the insert making sure that it is seated properly. With the insert sitting firm in place, take the adequate wrench (in our case, it was 7/16″) and start tightening the flaring tool.
The next bit of info is important – when the flaring tool makes contact with the line, apply 1.5 turns, stop and take the tool out.
- Step 7 – Double Flare It – The final step involves repeating the process. Leave the brake line clamped and install the guide tube back over the line. This time around, we’re not using the insert. Instead, just screw the flaring tool over the line and wrench it down until you feel resistance. At this point, execute ¾ of a turn and back off. That should give you a perfect 45-degree double flare.
- Hint: Practice the method first before you start. Also when you think you got it leave an inch or two to trim off if it goes wrong.
When bleeding reset brake valve if need be.pull out and hold.
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