Brakeline Flaring - bad instructionals, disinformation, youtube,

[GuyWithCavalier]

As someone who wanted to know how to make a custom brakeline, (replacing a GM line with non-standard connector),
I had hoped to find a simple guide on youtube.

What I found, aside from the usual youtube problems (waving shakey cameras, out of focus shots, meandering monologues, amateur hour) was that there WAS no decent video on this.

I did find various obviously critically important and useful info sparsely sprinkled across some dozen or so videos, as follows:

First watch AGS guide so you know the differences
and applications of the three main kinds of flaring.
Only DOUBLE flaring is relevant to GM cars (RE-USABLE lines)

AGS Guide: Explains 3 main types of flaring:
Only DOUBLE flaring applies to our GM car.
(Bubble flaring is for European cars, and is not re-usable)
http://www.youtube.com/watch?v=BcUGBdY1zWQ

How to make a Double-Flare:
Preparation of tubing by filing: See here at 3:10 minutes
http://www.youtube.com/watch?v=4fmF9mm3hsM
But this video has wrong side up, making a 'bubble-flare' (misnamed video)
You can also use a drill bit to clean out inside of tubing after filing.
The extra bit of filing the outside to remove any burrs is also good technique.

To do our flaring properly, we need a 3/16 extra piece (not included in our $20 kit).
Only the DOUBLE kit (full kit) is good for North American (GM, FORD etc.)
3/16 " is standard car brakeline: See here at 0.:24 secs for the right kit, but
Start watching the above video at 3:18 minutes to get going.
http://www.youtube.com/watch?v=0sah8ULW-mE

Before tightening down bar on tubing, this video is a MUST WATCH,
warning about the wrong way to tighten the bar to hold the tubing!
At 0:38 seconds, he explains the proper angle for the flaring for tubing = 45 degrees
Start watching at 1:36 minutes for the proper way to secure the tubing!
The guy in the previous video does it wrong, and no wonder he has broken his nuts.
http://www.youtube.com/watch?v=WXOo8MtDv7A
Also, at 2:10 he explains how to lock the press to the bar, something
not covered in other videos!
Flaring tools must be kept clean and lubricated (oil or brakefluid) to work.

This is the ONLY guy who gets the flaring bar the right way around!
Everybody else is using the wrong side (with the bevel/flare, for low pressure)
But the flat side should be used to create a right-angle shoulder.
The key point is at 1:40 minutes although he says he's making a bubble-flare here:
http://www.youtube.com/watch?v=KaO2jAWqVU0
From a visual inspection (at 4:50) you can see its a std. GM DOUBLE flare,
not a European Bubble-flare (5:47).


Now, not to run these guys down, for all their sincere efforts,
but there is a BIG BIG problem with this crap.
Many of the videos have absurd and dangerous advice,
mixed in with the other stuff, and most seem clearly unable
to grasp the essentials of the job.

I'm no expert at all here, but wow!

One guy says "its good to get it straight, but it doesn't really matter",
another says "you can use brakefluid to lubricate, but oil is okay, doesn't matter".
Nobody seems to care whether or not steel filings or shards end up inside the tube while 'reaming',
but most importantly, none of these guys seems to understand
that the fit is critically important in a high-pressure, high-temp environment. Its as if any shape flare will do.
Only one guy actually compares his work to a commercial line,
and even he gets the name wrong, misleading thousands of others.

Why can't anyone make one simple, good video on how to do this right from A to Z, which should only take about 5-10 minutes!

Another critically important problem is having the right fitting.
The kit that I bought at Parts Source (and Canadian Tire) has NO EXTRA FITTINGS AT ALL. its apparently useless for making a flare for a standard North American brakeline.
What are these people thinking? Can't they carry the right product, and doesn't anyone care whether the lines leak or not?

I went to a garage to get a line made, and they wanted $60,
and wanted me to supply the ends, because they don't carry the 'special' GM connector for two of the lines.
Most shops just re-use old connectors, so you aren't even getting new parts, just the line.

The Dealers (stealers) won't even carry the connectors up here (Toronto GTA with 6 million people to service!), or else won't sell them. Nor to they sell or stock replacement lines. They must be made on the spot for at least two lines.

But if these videos are any indication of how mechanics typically make up brake lines, who wants to trust any of them?

As technical person, I can understand the importance of properly shaping the ending of the line for high-pressure function.

Is there anyone who can tell me how to do a proper double-flare for a GM line without the custom extra fitting?
Or do I need to return the basic 'kit' and find a professional tool supplier?

[vgames33]

What "custom extra fitting" are you referring to? A double flare is a double flare, they're all the same and use the same fittings (for a given line size). Some newer (90s +) vehicles use a single (bubble) flare, but they are completely different and require a different type of fitting. Your car (a Cavalier?) may use bubble flares for the ABS unit if so equipped.

Reusing a brake fitting is completely acceptable, as the flare itself does the sealing. The fitting's job is to hold the line in place - that's all.

Anyway, making a double flare line is simple, but you will want to practice on a few sections of scrap line. Just cut the line to your desired length, clean up the end of shards and splinters (an 1/8" drill bit will help clean out the inside of a 3/16" line), and follow the directions that should have come with your flaring kit. The flare doesn't have to be perfect, as long as its straight (slight imperfections will fix themselves when the fitting is tightened, but a crooked flare will never seal). If it isn't right, you will know as soon as you attempt to bleed the system, as it will leak.

If you can't figure it out, just buy a premade line from the local parts store. Any supplier should carry standard double flare lines premade in lengths from 6" to 6'.

[GuyWithCavalier]

Originally Posted by vgames33

What "custom extra fitting" are you referring to? A double flare is a double flare, they're all the same and use the same fittings (for a given line size).

On GMs with ABS, there are two different threaded fittings on the same unit:

(Front to Back):

(1) Driver's Side front line to ABS unit: standard fine thread connector on both ends.

(2) Passenger Side rear line to ABS unit: standard fine thread on OTHER end, weird coarse thread on ABS end.

(3) Driver's Side rear line to ABS unit: standard fine thread on both ends.

(4) (Closest to Firewall): Passenger Side front line to ABS unit: weard COARSE thread on ABS end, standard connector on far end to flexible hose that goes to caliper.

On a Sunfire the ABS unit is sideways, but the pattern is the same.

There is no 'off the shelf' brakelines that have a different threaded connector on each end. Not even the dealers can order them. You have to make them up.

Some newer (90s +) vehicles use a single (bubble) flare, but they are completely different and require a different type of fitting.

Yes, European cars use Bubble-flaring, but the design and nature of this type means it is NOT reusable. Once crushed, it wont re-seal. Its a stupid design, which makes removing and re-hooking lines up an unreliable process.

This has nothing to do with thread-types however, just the flaring.

Your car (a Cavalier?) may use bubble flares for the ABS unit if so equipped.

No. This is incorrect. A close examination shows that all GM cars (and probably all North American cars) use DOUBLE, not BUBBLE flaring.

Reusing a brake fitting is completely acceptable, as the flare itself does the sealing. The fitting's job is to hold the line in place - that's all.

This may be true, but it is completely inconvenient, if you need to have a line made up, when the old line is still on the car so you can continue driving it to the garage and back.
I am replacing lines pre-emptively BEFORE They rust through and fail, and meanwhile I am driving the car, because I only have one car.
Its stupid for garages not to have spares,
and its stupid for GM to use two different threads on one piece of pipe. What morons.

...
If you can't figure it out, just buy a premade line from the local parts store. Any supplier should carry standard double flare lines premade in lengths from 6" to 6'.

Nobody supplies lines with a coarse thread on one end and a fine thread on the other end, of any length.

You can't "just buy a premade line" from any local parts store.
This is dreamland.

[vgames33]

Originally Posted by GuyWithCavalier

On GMs with ABS, there are two different threaded fittings on the same unit:

(Front to Back):

(1) Driver's Side front line to ABS unit: standard fine thread connector on both ends.

(2) Passenger Side rear line to ABS unit: standard fine thread on OTHER end, weird coarse thread on ABS end.

(3) Driver's Side rear line to ABS unit: standard fine thread on both ends.

(4) (Closest to Firewall): Passenger Side front line to ABS unit: weard COARSE thread on ABS end, standard connector on far end to flexible hose that goes to caliper.

On a Sunfire the ABS unit is sideways, but the pattern is the same.

Where did you source this information?

Originally Posted by GuyWithCavalier

Yes, European cars use Bubble-flaring, but the design and nature of this type means it is NOT reusable. Once crushed, it wont re-seal. Its a stupid design, which makes removing and re-hooking lines up an unreliable process

This has nothing to do with thread-types however, just the flaring..

Originally Posted by GuyWithCavalier

No. This is incorrect. A close examination shows that all GM cars (and probably all North American cars) use DOUBLE, not BUBBLE flaring.

Have you ever dealt with a bubble flare? They are very simple to make and rarely fail. They make sense from a manufacturing standpoint. I prefer them to double flares as the design makes them very unlikely to leak, even if flared incorrectly.

GM vehicles do use a single/bubble style flare in many applications. I can refer to my own experience on a 94 Cavalier and a 98 Malibu where bubble flares were in use (requiring the purchase of a bubble flare specific tool to make my repairs). The Malibu used a standard bubble flare for all of the ABS unit connections, with double flares at the caliper/wheel cylinder ends. Generic bubble flare style fittings for 3/16" line were readily available at my local parts store. The threads may not be different, but the end of the fitting that engages the flare is of a different shape.

If I remember correctly, many Ford vehicles from the 90s use a bubble flare as well.

I have personally reused a bubble style flare on several occasions with no leakage.

Again, the majority of fittings are readily available at most parts stores (at least in Ohio). Perhaps you are confusing metric threaded fittings with standard ones? Premade lines are usually hard to come by with a bubble flare, but I have seen them.

Originally Posted by GuyWithCavalier

This may be true, but it is completely inconvenient, if you need to have a line made up, when the old line is still on the car so you can continue driving it to the garage and back.
I am replacing lines pre-emptively BEFORE They rust through and fail, and meanwhile I am driving the car, because I only have one car.
Its stupid for garages not to have spares,
and its stupid for GM to use two different threads on one piece of pipe. What morons.

Why should the garages be expected to stock these "weird" fittings for your convenience? How many customers replace brake lines before one fails? And how many of those customers replace the lines themselves, yet lack the skill to make the lines?

Perhaps GM used different fittings to make the assembly process faster (different fittings make it easier to identify which end of the line goes where)?

The premade lines I mentioned are of the standard double flare type. Go to your local parts store and ask for a 6' section of 3/16" line. They will bring you what I mentioned. If you require something other than that, then you must make it yourself. Flaring a brake line is not a difficult task (though it does require practice), and the tools required can be found at any local parts store for under $40.

[GuyWithCavalier]

Originally Posted by GuyWithCavalier
On GMs with ABS, there are two different threaded fittings on the same unit:

(Front to Back):

(1) Driver's Side front line to ABS unit: standard fine thread connector on both ends.

(2) Passenger Side rear line to ABS unit: standard fine thread on OTHER end, weird coarse thread on ABS end.

(3) Driver's Side rear line to ABS unit: standard fine thread on both ends.

(4) (Closest to Firewall): Passenger Side front line to ABS unit: weird COARSE thread on ABS end, standard connector on far end to flexible hose that goes to caliper.

On a Sunfire the ABS unit is sideways, but the pattern is the same.

Originally Posted by vgames33

Where did you source this information?

By unscrewing the lines from my 1999 Cavalier from ABS unit.
As to the other end, I know they are standard fine thread,
because the rubber hose they screw into by the caliper is the same part (and thread)
on both the front driver and passenger side.

I know about the situation with Sunfire / coupes,
because I was just at the wreckers picking the connectors off other GM cars.

Have you ever dealt with a bubble flare? They are very simple to make and rarely fail.
They make sense from a manufacturing standpoint.
I prefer them to double flares as the design makes them very unlikely to leak, even if flared incorrectly.

I'm sure they do, if made correctly.
My point about reliability was regarding re-use,
not regarding buying new lines or making them well and installing them.

GM vehicles do use a single/bubble style flare in many applications. I can refer to my own experience on a 94 Cavalier and a 98 Malibu where bubble flares were in use (requiring the purchase of a bubble flare specific tool to make my repairs). The Malibu used a standard bubble flare for all of the ABS unit connections, with double flares at the caliper/wheel cylinder ends.

If I remember correctly, many Ford vehicles from the 90s use a bubble flare as well.

I'm sure when first invented, bubble-flares were tried by both GM and Ford,
but discontinued for obvious reasons (i.e., standardization).

I have personally reused a bubble style flare on several occasions with no leakage.

Generic bubble flare style fittings for 3/16" line were readily available at my local parts store.
The threads may not be different, but the end of the fitting that engages the flare is of a different shape.
Again, the majority of fittings are readily available at most parts stores (at least in Ohio).
Premade lines are usually hard to come by with a bubble flare, but I have seen them.

I'm glad you can get replacement lines for your Malibu or Ford.
Although it sounds as if they aren't as 'readily available' as you first suggested.

That doesn't help me with my Cavalier.
In my case, I have to make up custom lines,
even though the car is the most common car in North America.

Perhaps you are confusing metric threaded fittings with standard ones?

There is no confusion here.
I can tell visually that a coarse thread is very different from a fine one.

Why should the garages be expected to stock these "weird" fittings for your convenience?

Because GM is the largest car maker in NA.

How many customers replace brake lines before one fails?

Obviously not enough, judging from accidents traceable to brake failures.

And how many of those customers replace the lines themselves, yet lack the skill to make the lines?

All those that can't afford to pay a mechanic $60 or more for a custom line.

Perhaps GM used different fittings to make the assembly process faster (different fittings make it easier to identify which end of the line goes where)?

If so, the procedure was incomplete and ineffective,
since you can still mix up the lines,
because there are four holes, but only two different connectors.
Nor is this helpful for repairmen:
The lines are completely unmarked, although a simple letter-stamping
in the ABS casting would have solved this problem forever.

The premade lines I mentioned are of the standard double flare type. Go to your local parts store and ask for a 6' section of 3/16" line. They will bring you what I mentioned. If you require something other than that, then you must make it yourself. Flaring a brake line is not a difficult task (though it does require practice),

I was hoping there was at least one GOOD video on how to do it right.
I may have to wait a while for someone competent to do that.

and the tools required can be found at any local parts store for under $40.

Not in Canada.
Instead, both Canadian Tire and Parts Source (the two largest car 3rd party part places in Canada)
stock a useless flaring set which lacks the extra fittings needed to do a double-flare properly.

... unless someone knows a way of doing a double-flare without the extra 3/16" flat-piece.

[vgames33]

Can you get me a picture of the set you purchased? Any double flare kit I've owned or seen comes with the dies.

http://www.google.com/products/catal...ed=0CH0Q8wIwAQ


http://www.youtube.com/watch?v=usTvYMjwVdc

This seems to be a pretty straightforward video.

Are there any Sears or NAPA stores in your area? My current double flare kit came from Sears, and my bubble kit is from NAPA.


A Sunfire came through the shop today, and I saw the coarse threaded lines you mentioned. Not sure of where to find that style fitting, but hopefully you get your tool situation figured out.

[GuyWithCavalier]

Yes I might be able to post a pic of the set without parts.

As it turned out, someone else at Parts Source said that that kit was only for flaring fuel-lines and/or air-conditioning.
There was another kit available, and I swapped them out for an additional $10 (the original kit was about $20) for a total of $30 + taxes. I could have driven somewhere else and saved maybe $5, but between gas and time, it was easier to accept my fate.

So the updated more accurate info is this:
Parts Source HAS a 'double-flare' kit, and Can.Tire doesn't.


I tried the kit already, and the ends look small, but correct.
I had to tighten down the clamps very hard to prevent slippage of the brakeline while making the ends. The surface damage to the pipe was disturbing, but probably the brakeline still maintains its integrity.

Obviously, some of those professional versions costing a few hundred dollars probably do a better job with less scarring of the pipe.

As to the special fittings, which the dealers around here won't sell me,
I went to the wreckers and scavenged about four of them off a couple of wrecks.
I made one into a plug so I could remove the brake line from one wheel to get a length,
while still being able to drive the car at low speeds.
But that is moot, since I am in the middle of replacing the k-frame now, and the car isn't going anywhere today.

[maxwedge]

I have been making double flares for 40 years using the basic tool you spoke of and never had issues, the NAPa store has bubble style lines made but the double flare tool used carefully can also make them up.

[vgames33]

The scoring on the outside of the tubing is always going to be present. The nature of how the jaws clamp to the tubing makes it unavoidable. The expensive kits use a hydraulic ram in place of the screw type unit, but the scoring is still there.

If you get some leakage, I usually have success with over-tightening the fitting just a hair. Sometimes a less-than-perfect flare will straighten out with this method, but be careful not to pull the threads out by going too tight.

[GuyWithCavalier]

Originally Posted by vgames33

The scoring on the outside of the tubing is always going to be present. The nature of how the jaws clamp to the tubing makes it unavoidable. The expensive kits use a hydraulic ram in place of the screw type unit, but the scoring is still there.

If you get some leakage, I usually have success with over-tightening the fitting just a hair. Sometimes a less-than-perfect flare will straighten out with this method, but be careful not to pull the threads out by going too tight.

Thanks for the advice here and headsup on overtightening.

I installed the new line (it is coated with some kind of teflon, but is apparently still a standard steel tubing underneath (got it at Parts Source) and it flared well and doesn't leak at the moment.

Now whole front end is new except knuckles!
Tires are riding high, but I hope springs settle (quickstruts).

I am doing a basic alignment next,
and attempting to replace rear brakelines too later.
I will have to make one more custom line with the odd threadded connector for one of the back lines.
New shoes, drums, and springs, but same old cylinders at back. I may figure out how to replace those sometime

Thanks to all who replied with advice.

[GuyWithCavalier]

Originally Posted by vgames33

If you get some leakage, I usually have success with over-tightening the fitting just a hair. Sometimes a less-than-perfect flare will straighten out with this method, but be careful not to pull the threads out by going too tight.

By the way,
this won't be too helpful to a newbie like me,
unless you can also tell me the 'normal' ft/lbs for this fitting...
I guess its all by 'feel' and experience, but there should be some hard data somewhere or specs for these parts.