Double flaring brake line seal woes

Okay guys, whats your secret on sealing those brake lines? I take my time, and so meticulus at beveling the line end, deburing(all as per the instructions), and have a new double flaring kit. I tighten the lines into new blocks and hoses and 1/2 of them end up leaking till I tighten the living crap out of them till the nuts almost strip and round off even with my flare nut wrenches.......

The flares I have made look nice but why don't they seal better?

 

Take some pictures of your flared ends so we can see. Or go to the parts store and buy a pre made brake line and compare yours to the factory done ends.

 

Which flare kit do you have? There is a 37 degree and a 45 degree. If you double flaring 45 and installing on 37 it will leak.

Desert

 

I had the same problem with the brass T juctions. I had to seat the flare in a steel fitting then screw it into the brass T junction and all was good. Pissed me off as I had the buy new T junctions coz tighetening the shit out of them fucked the taper face.

 

I did 18 today. Two leaked. Post some pictures of your flares, the leaking ones, from a few angles, and the tools that you are using. We'll get you fixed up.

 

Shouldnt have to tighten them that hard. Do it normal, if they leak, back them off and tighten them back up. Usually cures the leak.

 

I had similar issues on two brand new hot rods I built.I used all new parts,when I took the leaking parts apart and looked at the brass fittings,it looked like the tube flare and the fittings inverted flare were not the same angles.The fittings had a very small mark where the tubing was making contact.I think most,if not all,the fittings were made offshore[no markings as to where],the fittings were also mostly metric[O D],so I bought metric tube wrenches!A friend replumbed his 40 Chevy,found the same issues/problems,he had bought his parts from a different supplier than me. ROY.

 

When you do the last step with the flaring tool don't tighten it down tight, just snug.Leave a little to finish forming/seal when you tighten the nut on the fitting.

 

The problem I have at times is due to the seam down the side of the tube. Makes it difficult to crimp a nice round flare that sits straight in the nut. peace

 

My flares look just like the ready-made flares, nice and smooth and same angle. I'll try the tip where you don't go to hard on the final step of the flare, that might be it. Thanks.

 

My biggest problem with double flare is the tool wanting to squash down unevenly, and messing the tube up on the first step. I wonder if getting a higher quality tool would help out. Which brand or type of tools do you all use?

 

Bluepoint

 

I bought an expensive kit from Napa.
I had never flared anything, followed the
instructions. Have never had one leak.
I've been doing mine and all my buddies
lines for 7 or 8 years. That being said, it
must be the tool cause I'm not very patient
or meticulous.

I'll check the brand name and report back tomorrow.

 

This tip works very well.

 

where are you getting your line? i bought/acquired some line one time that i couldn't get to flare properly.

 

I was in a jam one Sunday morning and had to pick up the only double flare set [imported] available at a local discount parts store. Had the same problem, looked close and discovered the holes in the tube holding bars weren't drilled at 90 degrees to the surfaces. Use the double flare buttons with my regular holder set and get good results. Didn't have much choice then but it reinforced my experiences that it's better to pay more for real quality tools up front, feel the price pain once, and move on. Beats being reminded how much I "saved" every time I have to fight tooling to get the job done...

I don't have the need that often now and getting along fine with my mismatch combination but when I invest again it will be for a high end set up to do metric, bubbles and all.

Ed

 

This^^^^^ And using a quality brand name tool. And wet the end with brake fluid to act as a lube when tightening.....

 

If you are using tubing that has a visible seam, JUNK IT! its cold rolled not seamless and will leak more times than not,
you want genuine bundy flex, with the anti corrosion coating, its dom tubing and will out live you.

 

I know it is kinda pricey, but I broke down and bought one of the Eastwood flare kits with christmas money last year....I was leery of spending the near 200 bucks, but I did get it on sale with a discount hoping the dam thing would work as they claim, and it really does.

I did my whole truck brake lines, fuel lines, and trans cooler lines (both single and double flare) and every one came out good, and do not leak.

My plan is not to loan this tool to anyone (like I did my now non-working Snap-On timing light) and keep it good for myself....LOL

 

That solved my double flared leaks when I tried it.

 

x2 !!

 

Earls, sells a flare saver that is made of dead soft aluminum and in cases where you can't get a good seal they work great. They are used in the aircraft industry, so I assume they are ok for cars. Be very careful when handling them as they will crush if you look at them crosseyed! I use stainless brake lines, and they are a little harder to flair and don't always seal the best. I have been saved more than once using them. Good Luck!

 

I fought this a couple years ago, and even bought another flairing kit to get one with a tighter insert. My issues were junk tubing. It was seamless, but the wall thickness was way off. I think it was old Speedway line, but not sure. Better tubes made it easier. I like the tip on leaving the last flair, it makes sense.

 

I've got a Bluepoint flair tool that I've had for 40 years and never had a problem with until lately with the tubing that is available at the parts houses now. I fought a brake problem on the wife's van last year because a flair I did would let it suck air in while not showing a visible leak.

Thanks for the tip on not squeezing the final part of the double flair down tight I'll try that next time I do one.

 

I have a KD Tools flaring tool that I bought way back in the last century, and it does a real nice job. Took me a few tries to perfect my flares, but I rarely have one that leaks. Make sure the end of the tube is cut square, deburred, and clamped well. And like mentioned in a previous post, leave a little "crush" in the flare so the fitting can do the final flaring.

For the most part, I quit loaning tools out a long time ago, seems like if they came back at all they were jacked up. I do have a couple of buddies that I trust with them, but that's it. I'm more inclined to take my tools and go fix whatever the wannabe borrower needs to fix.

On the flip side, I sometimes borrow tools, but I have this stupid idea that they should be returned in as good of, or better condition than when they were borrowed. Even if it's just cleaning them, so be it. If it's a cutting tool it is returned sharper than when I got it. Electrical stuff will maybe end up with a new cord on it if the one on it was crap. Gasoline powered stuff (pressure washer, tiller, etc.) gets returned with fresh oil and full of fuel.

 

And what planet are you living on ? Way too much to expect, that's why tools are best not lent out.

 

I have an Imperial flare kit. I have had others that the tube doesnt fit in well. Leaves a gap when tightened down. The "don't tighten down all the way at the end and brake fluid as lube" are great ideas as well. Also, a SHARP tubing cutter wheel leaves you with a better end. Those wheels seem to get ignored. Deburr the ID also. I use the little tiny Imperial cutter. Especially for small 3/16" - 5/16" tube. It has a wide roller that seems to work better IMHO.

 

just like Rustang I also bought the eastwood hydraulic kit and it is awesome, every time. If you are going to be doing a lots of double flare fittings it's worth the money. Yes it is pricey. Mine also does not go out on loan.

 

I chased 2 leaks until I replaced a new 3 way brass fitting with another new 3 way fitting. Quality product? yeah right!!!!!!

 

Could anyone describe the advantages/disadvantages in using 37(AN) vs 45 degree double flares? I know they use different fittings, but what else is different?