How to mate brake or fuel lines with a double flare union

I made this video to demonstrate how to mate brake or fuel tubing together using a SAE 45 degree double flare union. This is a really good flaring tool kit:

It will do both 45 degree SAE double flares and bubble flares as well.

[mulehead]

Great video!! Nickel copper lines is the key to making good double flares with that type of flaring tool. Trying to make nice and even flares with steel lines up under a vehicle laying on your back isn’t a pleasant job. Definitely nickel copper lines or go get the stock preformed lines. It’s a bad day when you have to lay under a car when fooling with steel lines and trying to make them work.

[jonathanmohr]

Some people use a compression fitting and your really not supposed to. How he's doing it is the right way 👍🏻

[raworthyel]

Thank you for this video. I've been struggling for 3 weeks trying to figure out why the feul line keeps leaking. Never knew a thing about flaring.

[vazza]

Great video, bought a silver line double flaring kit here in the UK, just wasted 3 hours trying to make it work, (copper pipe 3 sixteenths). Convinced now the instructions are wrong, they tell you to have the pipe sticking proud of the flaring block 0.5mm just made a mess. Noticed you used the die to measure how far out the pipe should protrude above the flaring block. Ah well have another go in the morning. 2am here now so technically it is morning. 🤐 off to bed, any more disasters will just take brake line and fittings to parts shop who provide a flaring service free of charge. Really wanted to learn how to do this myself, safety being paramount if am not happy with the results I will leave it to some one more competent. Thanks for your video, very clear instructions and video in great focus. ☺

[ohhman]

Very helpful. thanks for sharing this! really saved me time and money

[scrapplepig]

Thanks for showing us what it looks like after you double flare it.

[uponvp]

Awesome video. Much thanks! Keep em coming

[reidcoleman]

Very helpful and well explained. Thank you for sharing this video.

[erik]

your video should be number one, all the other ones are numb nuts using compression unions.

[lukedorny]

So…:
1. For carbureted engines, low pressure lines can be copper nickel and single flare, but EFI should use double flare.
2. Brake lines can be copper nickel but always double flare
3. Never use pure copper tubing on a vibrating machine or high pressure lines
4. Compression fittings are for home applications like AC and fridge water lines

Correct?

[tomlaskowski]

Rick Flair says "WOOOO!" IM SO TIRED OF THE WORDS "FUEL" "FLAIR" AND "FITTING" WITH THE ISSUES GOING ON WITH MY CAR RIGHT NOW !😀 I GOT A CASE OF THE "F ITS!"

[maximuswedgie]

I’ve been wondering what this fitting is called for two weeks been everywhere trying to find it. Thank you for this video this is exactly what I was looking for. Just wanted to throw out that I’m having a heckuva time with my flaring tool they all seem to kind of suck if you get them from the auto parts store because the steel line keeps pushing through it before it flares. I even drilled a hole through the center of mine and used another bolt and nut to hold the center so it doesn’t bow out. And it still pushed the tubing right through the flaring tool.

[Coodeville]

Lord only knows how they ever bent the line on my 307 Olds fuel pump to carb line? I had to cut it to get it off. The carb fuel inlet is very close to the thermostat housing. I'm going to have to make new ones and I see unions in my future

[dbdevkc]

Would you know if there is a SAE 45 degree double flare union that would joint the two lines at a 45° angle?

[dronedoutrc]

Good info. Will this work for High pressure fuel supply lines?

[williamkent]

I know I'm late to the party here, but could I do this on a fuel line from my fuel pump to my carburetor? Some people say, because of the slightly higher pressure, that it needs to be a single line with no unions...but putting in a union would GREATLY help me.

Anyone can respond! I know this video is older.

[aidansitler]

Hi, thanks for the video. What brand flare tool kit are you using?

[marksutube]

Where can I buy the union? It is hard to find a female to female M14.5 to M14.5

[sanghyub]

Okay, I did this for my brake line and it has a leak... I tightened it down as much as I could so it ended up stripping the union nut so I did it again and it's not as a bad of a leak but it still leaks lol

[brodieobrien-pickering]

good video. I was wondering how i could connect new lines to the very ends of my old lines. Is single flaring acceptable for a fuel injected vehicle, or do i have to double flare?