I have a leak in the 3/16" metal brake line that leads from somewhere under the brake cylinder up front all the way back almost to the rear axle. The rearward 3 feet or so of the line is corroded and I'm hoping just to be able to replace that part of the line. I've got a piece of just straight prefab steel line that's already flared and has the hardware on it. My plan is to cut my current brake line just forward from where the corrosion is and disconnect / unscrew it at it's rearward point. Then I'll shape my new line, screw it into the rear connection and bring it forward and splice it into the existing line after flaring the existing line.


Problem is I've never flared a brake line before. It doesn't look too difficult in the videos but in all those scenarios they're putting the flare tool in a shop bench clamp and twisting things down super tight explaining that if the tool that holds the line isn't tight the flare tool will push it out of position when it's cranked down. My issue is I'll be doing this under the vehicle and won't have the advantage of leverage to get everything tight enough.


Any advice about doing this under a vehicle?


also


Any advice on how to bend this 3/16" steel tube? sand possible? bend tool?

 

First return the steel brake line and buy some of the nicopp stuff in the size you need.

https://www.napaonline.com/en/p/BK_8135617

Second buy 2 of these connector.

https://www.napaonline.com/en/p/BK_6413290

Buy 2 of these.

https://www.napaonline.com/en/p/BK_6413296

Buy this.

https://www.napaonline.com/en/p/BK_7769000

Buy this flaring tool.

https://www.napaonline.com/en/p/SER161A

Watch this video.

http://www.sw.you2repeat.com/watch/?v=gfJmdZZr5GM

Now you can buy the flaring tool cheaper online.


You can probably find all the other pieces cheaper too.
Just have to poke around.
You are going to have to double check that I got all the sizes right.
Probably best to buy the brake line, unions, and fittings at an auto parts store so you
can screw everything together to make sure it is right.
Watch a brake line flaring video or two.
The nicopp stuff will flare like a dream with that tool and be easy to bend where needed.
The cool thing about that tool is that it is practically foolproof and made for flaring lines that
are still on the car. Something you can't do with a traditional one that an auto parts store
will loan you.

I hope I covered everything.

 

If you use what you got (as long as its not stainless) it is suppose to have a double flared at 37degree. If its stainless those do not get a double flare but gets a 47 degree flare which requires a different flaring tool. Also take a good lok at you other lines to make sure they are not rusted out also.

 

succesfully flaring steel brake lines is not easy, you need a decent quality flaring tool, not a cheap one...(can be bent with a cheap tool though)

if you have a local brake shop, get them to bend and flare

 

That brings up something I forgot to mention.
I recommended nicopp and that flaring tool.
Thing is I know it works great with the nicopp
but never used it on steel lines.

I do know somebody who wanted to replace a section of line
that I recommended it too. They loved it and if I had to guess
that they were deal with steel line.
But not sure.

 

If you don't want to go to all the hassle making up new brake lines, get cheap brake line in a variety of lengths ...and matcht close as possible the lengths you need, bend with your hands or over a large dowel/pipe ...and coil up whatever the excess there is. You don't really need a bender unless you are looking for 100% perfect bends, like on a restoration.

If you want an A-1 job close to stock, then yeah, custom fab is good. But I've had a lot of double flare's crack while making the final flare which is frustrating after taking the time to get the line bent and sized perfectly. Getting a good double-flare is not always easy w/o good tools. Cheap double-flare tool sets I haven't had a lot of luck with. Eastwood sells a nice (but not cheap) kit. But it IS rewarding when it works out well and yer custom fit lines look perfect and stock.

Good luck

 

Personally I would never just replace a section of line like I believe the OP is doing.
When I did my rear drums the long line from the proportioning valve to the brake hose
looked bad. So just replaced everything from the long line back.
With the nicopp stuff. Did use a union for the long line. Bought premade and cut them
down to the lengths I wanted flaring with that brake flare tool.
Until they started using that crap on the roads where I live I never replaced or flared a brake line.
With that tool and the nicopp stuff I flared like a champ.
I was pretty impressed with myself. LOL.

 

That's great feedback on the tool. I may give it a try. Thanks!

Yeah, when I redid my lines, I replace all the rears and hoses too (front lines were ok). Now I cover part of them in grease every couple years to help keep the rust away, mainly under the clips. Be nice if they made them out of stainless steel! Ha ha..

 

That is funny.
I do the exact same thing. I use Fluid Film there.
My fronts are fine for the moment.
I figure if and when I break a line, have to replace a caliper, etc is when I will just do everything up front.
That tool will only do 3/16" and some weird metric size.
The tool is cheaper at Amazon.
I paid more through the store then Amazon but less then the price at the link.
But if you do work with other sizes you might want to consider this:

https://www.napaonline.com/en/p/SER165C

Betting that you can find one like that online cheaper too.

Again though. No first hand experience on how that would work with steel line.

 

In the 60's and probably earlier, car manufacturers used to braze brake lines together using a silver solder (stronger than regular solder). A 2" or so long coupler was fashioned out of the next larger size brake tube ...which fit over 3/16" pretty well. The metal was cleaned and fluxed, then brazed (or soldered). People who work on classic cars may have seen that.

This is not a recommendation, rather a historical note as others have pointed out to me.

 

All I will add here is be certain that the rest of the line is good. Take a good look at where it is difficult to see to be sure. I just had to do a clutch line on a VW T25 the other day and it snapped in 3/4 places when removed. I could then snap more of it when it was all out. Granted a third of this line is out or sight whereas the brake line in question is more open so should be easier to spot corrosion.

Personally I'd say if you're going to the trouble of buying the correct tools to do the job, why not do the full line? You may not be able to route it the same as the original at the bulkhead, (mine doesn't follow the same path), but as long as it's clipped in a few places and not going to rub, you've got a full new line with one less join to try and leak.

 

Buy a stainless steel brake line kit from Inline Tube off ebay and be done with it. They sell ABS and non-ABS kits.

If you want to make your own, the cheap flare tools will handle regular steel and nicopp. They do not like stainless at all. If you want to flare stainless, you will need one of those $200+ setups made for a vice.

 

Thanks for all the help. I've learned a lot. After consulting with my regular mechanics I just let them do it because the whole line really needed to be replaced. As it went up through the engine compartment it just got too twisty for me. Peace of mind.

 

I don't think splicing in the line like you wanted was worth it.
But it was the question you asked. LOL
That is too bad.
That brake line is really easy to replace.
But I get it.
If your mechanic has not suggested it you might want to consider replacing the rear brake hose too.
If the 2 hard lines from the brake hose to each wheel are OK it should be no problem.
You are already there and the rear brakes need to get bleed anyway so.......
I am one of those "while we are here" types when it comes to my XJ.
Not really good for the wallet but.........

 

Thats the hard way, as you found out. You fish the long line thru from the top, not from underneath. The other end of that line has far less going on and is easily routed over the transmission crossmember and behind the parking brake bracket. The lines that snake along the firewall are the PITA. If its one long line like factory, its even worse.