TheSamba.com :: View topic - Anybody know if/how to splice metal brake lines?

Wed Sep 07, 2016 11:13 am

Full disclosure, this is for another vehicle but the topic will doubtless benefit us all since our brake lines are 30+ years old.

I have a failed brake line on the car. The metal line is over 12 feet long, wending its way from the firewall to the rear axle. The failure is in the last few feet. I have made brake lines before - bending and cutting and flaring and all. However, I have never inserted a section like this.

Anybody care to comment on how to do it? Many cars have their hard brake lines in sections, so I feel like there is no safety hazard, but there is likely a right and wrong way to do it. Thanks!

Doug

Wed Sep 07, 2016 11:19 am

Edit: DON'T use compression fittings. Sorry for the bad info, it was just what I did when I was a kid and knew next to nothing, except that I needed the brakes to work 'stat'. The guys at the Napa store didn't educate me, and the line didn't leak, but more education was obviously needed.

Back in my '70 Beetle days I had to do some of this. Went to the Napa parts store and got compression fittings, and some lengths of metal line. The metal lines are somewhat bendable, come in a variety of lengths. Cut back line to good, fit compression ends on, and tightened it down. Bleed brakes, get on my way.

Wed Sep 07, 2016 11:22 am

any splice sounds like a baaaaaad idea Doug

Wed Sep 07, 2016 11:35 am

Merian wrote: any splice sounds like a baaaaaad idea Doug

Oh pisshaw!!! ^^^^

With the proper flare tool and a brake line Union this can be as safe and leakproof as a new brake line.

You need. Double flaring tool
Or
A Bubble flaring tool

The proper fittings for your line size and fitting style
Proper Union for the above fittings.

It's no worse than connecting to a caliper or cylinder.

The sky won't fall, you won't die and the Sun will rise tomorrow on a properly spliced brake line.

Dave

Wed Sep 07, 2016 11:43 am

bobbyblack wrote: Back in my '70 Beetle days I had to do some of this. Went to the Napa parts store and got compression fittings, and some lengths of metal line.

I fixed the brakes on an old snowmobile like this, was far easier than I had expected.

Wed Sep 07, 2016 11:45 am

Put a fitting on the old line and flare the tube, put a fitting on the new line and flare the tube, put a coupler in between. It's done all the time.

There are mainly 2 different types of fittings and corresponding flares, make sure you use the right flare tool and fittings.

Use nickle copper brake line. It's easier to flare and you can form it by hand

Wed Sep 07, 2016 11:46 am

Dave - when are you moving to Idaho, man? You are a regular renaissance man with multi talents. No wonder you are a Vanagon owner - you were made for it and vice versa.

Doug

Wed Sep 07, 2016 12:31 pm

MayorMcCheese wrote: ...There are mainly 2 different types of fittings and corresponding flares, make sure you use the right flare tool and fittings...

Unions are pretty common on some of my other cars and a perfectly reasonable way to deal with complex lines.

Wed Sep 07, 2016 1:39 pm

djkeev wrote: Merian wrote: any splice sounds like a baaaaaad idea Doug

Oh pisshaw!!! ^^^^

...

Dave

not liking the Idaho sheep jokes, eh :?:

Wed Sep 07, 2016 9:14 pm

Sheep? We herd tourists around here. You must be thinking of Southern Idaho where they wear tall boots for the sheep.

So, a bubble flare tool would be best? I'll go get a flare tool and small tube cutter tomorrow. Getting the fittings is on the list as well.

Doug

Thu Sep 08, 2016 12:06 am

IdahoDoug wrote: ... So, a bubble flare tool would be best? ...

As noted previously there are several different types of flares. single, double, bubble, double bubble, American, English, German, Japanese. Do some research before you spend your money. For my '69 camper I was able to get some short pieces at a FLAPS. Other pieces I ordered from a VW parts vendor.

This is the tool for bending the lines. Also available from FLAPS.

A previous poster mentioned using compression fittings for joints. That's fine for water lines, not for brake lines. While you're doing brake lines consider replacing any rubber brake lines and a brake fluid flush.

Aloha
tp

Thu Sep 08, 2016 12:09 am

Bubble flare is what the vanagon has from the factory at the ends.

Thu Sep 08, 2016 5:54 am

MayorMcCheese wrote: Put a fitting on the old line and flare the tube, put a fitting on the new line and flare the tube, put a coupler in between. It's done all the time.

There are mainly 2 different types of fittings and corresponding flares, make sure you use the right flare tool and fittings.

Use nickle copper brake line. It's easier to flare and you can form it by hand

That's exactly how I fixed the leak on my Syncro. I ordered several VW blocks & tees (& the correct male tubing fittings). You can use a 45° flare tool to do it, but you omit the last step when you flip around the button, when the flare is still a "bubble". I have a rigid 345 flare tool kit (see below). Be sure to get NiCopp or Cunifer lines - not steel

https://www.ridgid.com/us/en/345-manual-flare-tool

I would recommend not using a tubing cutter on a line you plan on flaring. It tends to thin out the metal on the cut, & it splits the tube, especially during the last step when making a 45. Cut the tube as straight as you can with a hacksaw, hi-speed, or dremel.

Here's one of my fuel line projects for a boat motor.

Thu Sep 08, 2016 6:21 am

looks like this has been covered with the proper info... but I must say this for future audiences who may think such a thing is okay...

DO NOT USE COMPRESSION FITTINGS ON BRAKE LINES!!!!!

Quote: "Despite this, many people choose to try brake line compression fittings for line repairs. Compression fittings are used to join two pieces of brake line together. This form of repair is common because of the idea that the fitting prevents leakage. The compression fitting is comprised of a nut and a ferrule. When placed on a brake line, the fitting creates a tightened joint.

Unfortunately, using brake line compression fittings presents multiple problems. Because your brake system creates a substantial amount of pressure, the compression fittings are prone to failure. In addition, compression fittings are known to leak when used on brake lines, causing a loss in brake fluid, and ultimately failure of the braking system.

You cannot, under any circumstances, use compression fittings to repair the lines on a public transportation vehicle. Many states have banned the use of this repair on passenger vehicles, too. In addition, you might find that compression fittings will cause your vehicle to fail inspection."
http://www.brakeconnect.com/top-3-reasons-not-to-use-brake-line-compression-fittings

Thu Sep 08, 2016 7:21 am

The bubble is not really that superior to other flares.. so if this is just adding a union on an existing line... then go with a simple single flare. (especially since its not your vanagon)

Old brake line material does not like to flare cleanly.. it may tear or split or come out uneven.. but if you're careful, it should work.
Find the cleanest area of line with least external corrosion to make the cut and flare.

After assembled.. Just check for leaks. and if it does leak, then try again and patch in a longer new piece to replace the old.

Thu Sep 08, 2016 8:04 am

FWIW - O'Reillys (and others) have a free loaner tool program that includes the flaring tool and bending tool:

http://www.oreillyauto.com/site/c/RentalTools.oap

I have never used their loaners for this task but based on other tools I have borrowed from them - do inspect them for damage as they have sometimes been abused by ham-fisted customers.

Thu Sep 08, 2016 8:15 am

Speaking of bubbles, a repair seems like adding a location that can harbor an air bubble. May require a power bleeder for that line.

I agree about the compression fittings, you wanna be CERTAIN it can NEVER squirt the tub outta there. A flare tool creates a structural connection. It's much better. Flare is best, minimum opportunity for leaks and better bleeding.

A crafty fella in a bind, can tighten a compression fitting then unscrew it and 'expand' the protruding tubing end a little (to ensure the ferrule can't slip off). 1,000psi on a 5mm steel tube end is appx 10 lbs pushing the tub out thru the ferrule. Not much. It's pretty easy to mechanically lock it against 10 lbs, or even 100lbs. Think about this for a moment though, how is that air bubble gonna get out of the union with a protruding tube end on each side?

Thu Sep 08, 2016 8:36 am

I must say I am super impressed by the talent of this group. My hard break lines were rusty and broke when the specialty vanagon shop was doing work on the brakes...as a result the hard brake line needed to be replaced. The shop cost to manufacture and install the new line was $1000.00

While I understand not all places charge the same labor rate as the seattle area but if it makes you feel good, just know you are saving yourself this kind of cash if you are doing this yourself and not having to get the shop to do it....

-dsd

Thu Sep 08, 2016 8:48 am

Scabbing a new piece of hydraulic line onto original tubing is not only unsafe, but not real smart.

If this hydraulic line was on your garden tractors end loader, or your back hoe's bucket cylinder maybe.

You wouldn't be putting other folks in jeopardy for your error in judgement.

Real piss poor idea.

Replace the entire line in one piece.

No scabbing a new section onto a antique, failing section of brake line.

Thu Sep 08, 2016 9:15 am

I purchased a bubble flare tool to join new hard line to new hard line near where the spare tire sits. This joined the new hard lines from the master cylinder to the rest of the system.

Was having a hell of a time getting a one piece line to bend and fit from front to back during a cold spell and not much clearance to deal with under the van.

The PO had sliced a diced at least 6 joins where the lines rotted out and he spliced in a fix, sometimes only about 6 inches long !

I used metric fittings and I forget why, except maybe the obvious choice for a German VW and compatibility.

Your connectors that you plan to use should match the type of flare you want to use obviously. I also replaced the flex lines while I was at it.

I was more worried about all the other piss poor design choices and materials that VW used ( firewall spigot that I replaced with billet, etc ) than this choice.

After all, as far as I'm concerned, every brake line has a compression fitting at each end where it connects to flex lines / calipers / clutch slave / Wheel cylinder(s), etc.