How to Flare Brake Lines for Your Truck, Car, or SUV

Do you need to make new hard lines for your brakes, but don't know how to flare them? Watch this video, and learn how to do a double flare and bubble flare on steel brake lines!
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⚠ DISCLAIMER:
While 1A Auto strives to make the information provided in this video as accurate as possible, it makes no claims, promises, or guarantees about the accuracy, completeness or applicability of the content. No information contained in this video shall create any expressed or implied warranty or guarantee of any particular result. All do-it-yourself projects entail some risk. It is the sole responsibility of the viewer to assume this risk. 1A Auto is not responsible or liable for any loss damage (including, but not limited to, actual, consequential, or punitive), liability, claim, or any other injury or cause related to or resulting from any information posted in this video.

[@1AAuto]

√ *Watch the Video* √ *Buy The Part at 1A Auto* 1aau.to/m/Visit-1AAuto √ *Do it Yourself* √ *Save Money*

[@olveragarage]

Hello where can i buy the tools? Thanks nice video

[@TrailVapor]

@@olveragarage Where can I buy a bubble flare tool?

[@billspezza3922]

One thing I would like to add. I spent 40+ years as an HVAC tech, used single flares all day long and the only thing missing from this video is the use of a reamer to take the ridge out of the tube before you flare (any type of flares). Nice clean finished product, and a superb fit. Thanks for this video, nicely done,

[@contraband1543]

Yeah I use single flares on brake lines all the time and they never leak. It is the worst way but it does work if you know what you're doing

[@ronc4146]

Yup, single flare = HVAC all day. Lower pressures than a vehicle brake line.

[@dalehood1846]

EXTREMELY WELL DONE VIDEO! I have been an Automotive technician since the 70's and worked on a top fuel race team for three years. This gentleman explains EVERYTHING CLEARLY. Side note- You can always learn something new, you will never truly know it all. Thank you so very much.

[@1AAuto]

+Dale Hood Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c

[@1232bluejays]

I've bled my own brakes might as well learn to replace my old brake line. Amy way to minimize brake fluid loss after cutting a line? I recall a shop charged me almost $300 to replace a section of line once

[@Xxmeca421xX]

I put the line in the tool upside down and file it level. Then I use oil during any process to flare to prevent cracking.

[@DavesWheeling]

I like when this guy does tutorials, explains everything very well.

[@lostintime8651]

GReat video!!

[@charliegrutz]

This is the best demo I've seen on flaring brake lines.

[@JaseUKHunting]

I've seen about 10 different videos of how to flare brake lines and this is the only one that has not only spoken about but explained the alternative use of bubble vs double and to make sure you use what you have removed from your vehicle. Excellent step by step guide, only thing I'd add which makes it easier for viewers is you could add points in the video to click to the relevant flare you would like to achieve but that's a minor thing as people can skip if they wish. Thank you for taking the time to make this tutorial

[@rglmotorsports2989]

"It's not about that Hercules..." I love it!

[@DarrenSteele-mx3ks]

My car was in an accident the brake line snapped at the fitting and to my surprise it was the "bubble" so that is what I will put back on thankyou for this post!

[@Deerector]

His tutorials are by far the best. 1A auto..... DO NOT STOP MAKING VIDEOS WITH HIM!

[@larryfine4498]

Single flares have their place in some applications, but NOT automotive. When I was taught the process, we were told those single flares are prone to splitting under the constant vibrations cars endure when driving. Always use a double flare.

[@sergeibzk]

Finally, after watching 3 videos about the same topic, on fourth I found the correct one. Very nice close up shots and straight to the point explanations! 👍 This is how it should be done ✅ Thanks a lot to your team 🤝

[@shane14424]

Thanks for the video. Thought I could get by with a cheap flaring tool but after seeing yours I think I'm gonna upgrade.

[@edjohansen4231]

I'M GLAD THAT I WATCH THIS VIDEO...!! FROM NOW ON. I'M MAKING MY OWN FUEL LINES,BRAKE LINES,COOLING LINE,ETC... I OWN A 24 YEAR OLD TAHOE Z71, AND LIVING IN THE NORTHEAST.. EVERY LINE GETS RUSTY. NOW I'M GOING TO MAKE ALL NEW LINES MYSELF.. THANKS FOR YOU VIDEO..!!

[@1AAuto]

+@edjohansen4231 Thank you! We love empowering our customers and showing how to perform DIY auto repairs with our high-quality auto parts. 1aau.to/m/Shop-1AAuto-c

[@mostlycars7586]

Awesome. I am installing a line lock on my beetle and I am struggling to find metric to sae adapters. I'm just going to flare my own lines with the proper fittings. Something I have avoided, but this video will help me do that.

[@FeelTheDrive]

I'm crying because I should have watched this video before I did my lines and now I have to do them again

[@1AAuto]

+Feel The Drive Thanks for checking us out. Shop for high quality auto parts on 1AAuto.com: 1aau.to/m/Shop-1AAuto-c

[@ejwxb2561]

awesome video - thanks so much for posting as I am getting ready to do some flairs and really wasn't sure how.

[@madmanmechanic8847]

I like your no bullshit type of teaching very simple you didnt go very fast which is key and to the point and most of all simple . I got one of those Hyd flaring kits and still learning on the different flares . It has some GM push dies etc thanks

[@nfprojectshop]

Glad I watched your video, don’t realize there’s a double and a bubble and there’s a difference! Note I’m heading back to town for new tools🎉

[@bwagenberg]

Love the closeup of the three flares side by side. Great video.

[@1AAuto]

+Bruce Wagenberg Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c

[@Steele44320]

Great info. Had been trying to figure out what type of I have on my VW high pressure fuel line (bubble).

[@omax1023]

Great educational and instructional video for the "do it" yourself at home mechanics! Thanks 1A auto for a proper brake line tutorial! This was helpful, I replace my corroded lines on my 02 4X4 Mitsubishi Montero.... using the bubble flaring tool with ease and confidence, my SUV is stopping better than ever! A word to the wise, check your rotors, pads, and brake hard lines and hoses periodically! Be safe everyone....

[@numbersandletters5149]

Thank you for this video i am going back and redoing my single flares 😳

[@brianyoung9945]

Now I have to redo 4 single flares 😩

[@billrandolph9318]

Really nice job of explaining how to make a double flare!

[@rodx5571]

I just got the Mastercool bleu hydraulic flaring tool, with the 3/8 and 1/2" jiffy tites for GM transmission and oil cooler lines. Its awesome. I just couldnt deal with using the manual tool anymore.

[@ericwilkes238]

How much was it

[@morganmc32]

Super helpful, down to earth guidance. Love your videos and parts!

[@tomctutor]

I see that some auto mechanics use anti seize or copper grease to avoid the flare tool causing cracking on the end, for all it takes a little grease I would recommend to do that!

[@davidfrank2824]

I know this is an older video but I'm hoping what I have to say might help someone out one day. I have been working on my own stuff and friends and families since the 1980s. For whatever reason I seen to be attracted to broken brake lines. I honestly cannot tell you how many times in my different vehicle that this has happened to me personally. The way I normally would fix it would be a compression fitting. At the time my friends that were mechanics are the ones who showed me how to use that. I can honestly say I had never had a problem until now. 5 years ago I was traveling at 50 miles an hour and put my foot on the brake pedal and it went to the floor. As I'm coming up to the red light I looked in my mirror and was able to get onto the shoulder safely. I was able to get my truck back to the house. Jumped in my other vehicle drove to the parts store picked up some compression fittings. I already had more than enough brake line in the garage. Like normally I went under cut my lines put the new piece in and then I bleed the brakes. That vehicle doesn't get driven much but it has been driven since the brakes were fixed. Christmas Day 2023 I was heading over to my family's house add halfway there to brakes went to the floor again. Since I don't live far from my sister's house I just drove there. I looked under real quick just saw brake fluid everywhere. The next day I put more fluid in there and had my friend pump the brakes up after topping off the reservoir. Sure enough the compression fitting is what broke. Now I could have just taken it apart and put it back together using some new line and cut away more of the brake line. I decided not to do that since I have seen numerous people make videos and tell you to never use a compression fitting on your brake lines. Never had a problem thought they were just talking to hear yourself. Everybody was 100% right who says don't use a compression fitting. Unfortunate enough to have an Eastwood store less than a mile and a half from my house. I picked up a flaring kit and picked up brand new brake line since the stuff in my garage is over 30 years old. It takes a little longer especially when you are flaring the original brake lines underneath the vehicle. Since my truck sets up high enough I don't have to use a jack. Now I have the Peace of mind knowing that this should not happen again. And if any friends or family ever have this issue and come to me this would be the only method I would use one last night I don't really like the person. -) sorry for how lengthy is was but I wanted to stress the point on doing something right. I love all the videos that have 1A auto puts out. Not only do I watch the videos I buy from them all the time. I still have an intake manifold to put on the same truck that had the brakes go out and that came from 1A Auto. I appreciate good videos and showing exactly how to do something.

[@ooCHICOoo]

great tutorial clearly and DIY thank you for sharing my friend

[@Queensraces]

Wow great video thanku i was doing single falresand it was leakinng now gonna do double.. so does a double flare fit into a inverted connector??i know it can fit but is that the right way?

[@jackbeanstock7710]

good video , clear and to the point.

[@AMC-eq3jr]

Expert knowledge presented. Thanks for sharing.

[@james7905]

Give this man a raise, great tutorial!

[@1AAuto]

+James Thanks for checking us out! 1AAuto.com

[@MattSchmader]

This video is a life saver 👍🏻

[@JoshuaMHiggins]

You're awesome, to the point, and made it very simple to learn. Cheers from the UK! :)

[@1AAuto]

+Joshua Higgins Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c

[@bigears4426]

Plenty of old cars run single flares , never had a problem with any

[@OldSchool-ot9rp]

Probably because they don't have power brakes. Less pressure.

[@DavidJackson-zc4eq]

Probably because most of their owners died when the brakes failed

[@dannyvenegasiboa5101]

@@DavidJackson-zc4eq 😂😂😂

[@AznilAzni]

May I know, is there any way to connect a 1/4" brake line tubing to a 3/16" brake line tubing? Because the issue is now, my car used 1/4" tube for the connection from the ABS pump to master cylinder. However, as I want to change my brake booster from single to double layer, I found that the master cylinder that fits to it is the one that using 3/16" tube. Can you give me the idea of any reducer or union or adapter that can be used? Thanks!!

[@MaxMax-fb5dv]

Which tube nut do you use with double flare end? The "tube nut standard flare" or "tube nut inverted flare" fitting? Dorman 785-460D or Dorman 785-290D?

[@djsvirgo]

Hi wonder if u can help in anyway. I've used double flare with a full threaded nut. My vehicle obviously had bubble flare . Will I be ok .

[@StephenClarkDobson]

Love it! Keeping it simple.

[@Ivan.topp.]

I would recommend reeming the pipe and filing the end flat, this allows the adapter to fit flat resulting in a perfect flare

[@noahnoegonzales4571]

Great instructive video! Thanks!!

[@kurtwm2010]

New to this. Planning to replace brake lines on a 1999 Durango. Seems relatively easy to flare copper lines. Question: once I disconnect my old lines, will it be clear which type of flare the old line is? Once a double or bubble flare is crushed don't they seem to very similar in looks?

[@cosimosanfilippo9050]

Fantastic tutorial , but I would like to know how to double flare 3/16 304 Stainless Still brake line, so far I haven't found any information regarding it. I would appreciate your help please.

[@howtodoitdude1662]

If I’m using a union to attach a small section, does it matter if it’s a double or bubble flare? I will be flaring both ends.

[@daviddevries65]

Great video. Thanks

[@RamonLFrancisco]

Lenny is a great instructor! Thanks.

[@1AAuto]

+Ramon Francisco Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c

[@thaunseencamp1009]

Excellent tutorial man.

[@Rizzel101]

Great Video A1! Thanks!! ❤️

[@bornhayes2289]

Great Job same way I learn at college!

[@MrBmoll5858]

Thanks for sharing. 👍

[@MichaelSimmons.]

Thank you. Excellent video. Very well explained.

[@1AAuto]

+Venom101002 Thank you for the feedback and for watching!

[@rayhewitt4688]

Thank you for that video it will help me out a lot

[@easymike7176]

Great video! Thanks!

[@RjFitness360]

Awesome! What brand of tool did you use for bubble flaring?

[@cynthiafougere8404]

Manny thanks again to you Len and all those who make up the different videos. They are short,right to the point,very informative,and must I say very well illuminated. There’s nothing worse than watching a poorly lit video. Lester from Nova Scotia

[@1AAuto]

+Cynthia Fougere Thanks for the feedback, Lester! We are happy to hear you are enjoying the videos we put out!

[@autopatina8337]

Very good video, thanks

[@kalenburns4190]

does it matter what flare is used as long as it matches the tube nut or union its going into? (one side bubble/one side double)??

[@Harry244ful]

You have been a great help guys! Thank you!

[@1AAuto]

+Harry244ful Thanks for checking us out! 1AAuto.com

[@nickayivor8432]

Helpful video thank you 👍 👏

[@dwwd156]

Well done

[@Drifter077]

Very good video thanks

[@davemunday2652]

These guys are the best

[@dcasteaux9181]

Very well explained. Would add that you should only use quality tools to do this job: cheap tools may cause poor results. Also, ensure that if you use copper nickel brake piping it’s is copper-nickel mixture and non-magnetic. If it is copper and magnetic then it’s probably substandard copper-coated steel.

[@josephburnham4621]

Great job

[@roadstar499]

nicop line very cool... and wont ever fail

[@thesickening0169]

Regarding the fittings, in the video the fittings arent threaded all the way to the end of the fitting. Does it matter if fittings are fully threaded or not?

[@gregscrap]

Great video ty keep it up.

[@Iamtherodlight1453.]

Awesome thank you sir

[@boydjoiner4652]

Good instruction, thank you!

[@1AAuto]

+Boyd Joiner Thanks for checking us out!

[@omartorres3007]

How does your tool cut through the brake line so easy? This rental tool from Autozone goes tight within a half turn

[@anthonykupchunos4282]

Thank you 🎉

[@sergioalejandre306]

Nice job

[@MMFLERC17]

Good job man thank you!

[@williambritcliffe2211]

Pretty useful showing the different flares

[@1AAuto]

+William Britcliffe Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c

[@nealbaker2132]

Thank You 1A Auto.

[@1AAuto]

+neal baker Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c

[@biryaniofbodyhair]

Excellent video thank you

[@1AAuto]

+salixofthewoods Thanks for checking us out. Shop for high quality auto parts on 1AAuto.com: 1aau.to/m/Shop-1AAuto-c

[@vincentchalmers72]

Awesome- thanks👍

[@danielfisher1204]

Do you have a link for the Bubble Kit?

[@Titan-uy1qy]

Thank you sir

[@dano4572]

very good. thanx

[@mauroarantes9407]

Very good video

[@olveragarage]

Nice video 👍where you bay the tools?

[@MikeZyouthpastor]

great as always!!

[@ogronanet]

Otima instrução, satisfatorio o seu video. Bem explicativo, mas se tiver o link das ferramentas agradeço. Obrigado pela instrução, vou ganhar dinheiro de verdade com essa dica. Sucesso e Paz! Great instruction, satisfactory your video. Very explanatory, but if you have the link to the tools, I'd appreciate it. Thanks for the instruction, I will earn real money with this tip. Success and Peace!

[@kevinbeuger2081]

Is the bubble flare SAE or DIN/ISO? They are different and incompatible with each other. The latter flare has a flat back side, whereas the SAE is conical to match the concave depression in the SAE nut. Double flares are getting more rare because the folding back of the metal often over-stressed it and caused a crack when formed. Bubble flares are less prone to splitting or cracking because there are no 180 degree bends like in the double flare.

[@kevinrafferty5617]

Bubble is ISO.

[@davidkozelsky]

Thanks!

[@norwich93CMP]

Nice put you did not review how to prep the line before flaring.

[@Jmas369]

Very good

[@ronv6637]

Did you use cupronickel (easy) or steel (hard) or stainless(very hard/special tools)? Do you sell fitting kits-do not try to reuse old fittings.

[@APC9906]

Thanks man.

[@josephward8274]

Hey kid FYI 2009 Saturn Aura secondary lines going from master cylinder to abs module is 5/16 line. Just did them today.

[@OldSchool-ot9rp]

Late model F150 4x4's are too

[@stedmangilday2416]

Good Pipe bending 3/16 aid use 3mm nylon strimmer cord down length of pipe if you not got piper bender Must be solid strimmer nylon cord polyethene/polyprotein is to soft

[@AlloyedFrequencies]

Thank you 🙏

[@plurplursen7172]

The single flare is used in low pressure HVAC and Espresso machines

[@muleblues71]

How about single flare for stainless?

[@uriahmorgan3879]

I strongly recommend using double flarusing double flares but when you're in a pinch and need to just get the car home Single flare will get it done I have an f250 With the repaired brake line that I had to use single flares cause I was on the side of the road just need to get it done quickly I am still running that truck 3 years later

[@1AAuto]

+uriah morgan Thanks for checking us out. Shop for high quality auto parts on 1AAuto.com: 1aau.to/m/Shop-1AAuto-c

[@bluemax229]

You used a flare nut that is specific for a BUBBLE flare (only), but used it to demonstrate the DOUBLE flare as well? With a double flare, the threads go clear to the end, whereas with the bubble flare the threads clearly leave a smooth, unthreaded portion of approx. 1/16". They are NOT interchangeable, as a BUBBLE flare nut is METRIC, and has 10mm x 1mm thread, and the DOUBLE flare nut is SAE, using 3/8-24 thread. A further distrinction. . . . the bottom of a BUBBLE flared brake line is flat, but the bottom of a DOUBLE flared brake line is angled (I believe 45 degrees?). Otherwise, great video.

[@yinyanglovebomb]

Awesome vid

[@1AAuto]

+Joshua Briseno Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c

[@kakeetoalex9924]

Awesome..