(quickly, read the Subject aloud 3 times )

Eye-saving summary:

At the very end I ask if the fitting designed for the bubble flaring may also hold the Double flared tube tightly in place and properly sealed.

UPDATE a few hours later: You can also read my next posting here before reading the "full version". I found a website with illustrations.

Car:Fiero 86, 5sp Isoozoo, Tech4 inline rubber bands (aka iDuke), Flintstone Heavy Duty Brakes with new Reebok "pads"

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Full version:

The saga continues as I prepare to work on the car again tomorrow. I want to make sure that we are not confusing bubble and Double, please excuse the heavy markup. I need to properly flare the end of the steel line on the rear brake behind the driver (see topic Brake hose>steel line frozen. Indications were that a Double flare could be used so...

Thanks to John Stryker's advice, I went to get some scrap steel tubing to practice making good Double flares with my new kit. A parts store had 20" lengths of 3/16" steel lines with the fittings (or end nuts) installed. BOTH types of flaring were available. I discovered that the fittings in these 2 steel lines are actually different -- not just their respective flare types .

I matched them at the store into the new brake hose that I have. The bubble flared line fit perfectly. Not so the one with Double flaring. Here, the fittings do screw smoothly into the hose end, but the steel line stays loose. Obviously, no good. WTF, why are so many telling me to use Double flaring?

So, to do this right I HAD TO bubble flare the line in the car at the point where I'll cut the old damaged end? It seemed like I had no choice but to get the expensive $100 bubble flaring kit. Another problem: the nearest such kit left at a store in South Florida is about 50 miles away and the blasted traffic is heavy. Plus these kits are non-stock items, their computer says it is there but they weren't able to confirm it physically.

At that point, a thought came to mind. If these things are SO hard to get and expensive, what are the Fiero crowd and other GM owners doing? I gather that many:
-- save the old bubble type fittings (or manage to acquire them new, hard as it is)
-- but then they use them with Double flaring (instead of the original bubble flaring) ...
...because, darn, it LOOKS like this could work! This would explain why so many people suggest a Double flare be used.

In other words, the fitting designed for the bubble flaring may also hold the Double flared tube tightly in place and properly sealed. Is this the case? Is it safe?

TIA for the help,
Beno

[This message has been edited by Jdlog (edited 04-01-2005).]

there is something wrong if the nut doesn't tighten the line down when you double flare it. Double flaring is the industry standard for brake connections involving any type of flares and I have never seen what you are calling a bubble flare

^^^^^^
What he said. A D O U B L E Flare is what is used on brake lines on every American car I've ever seen.

John Stricker

Ha ha, folks...I reaaaaally want you to be right. I don't have a camera at hand, which would allow me to illustrate. I'll see if I can find something on the net quickly.

Darn, this was quick: see here http://www.agscompany.com/productFS/brakes/brakes8_table.html

Now, what they call a "standard flare" looks to me as the Double flare that I can make with the flaring kit I have. In fact, I just realized that the both pieces of steel pipe I bought to practice with, are made by these people under different brands. I have a BLJ-308 ("Standard" and found under Domestic Brake Lines) and a BLB-20 (bubble, found under "Import/Metric Brake Lines"). The latter is under "British" where they add "Bubble flare with US/Domestic thread fittings".

My impression, and what I'd like to think, is that if you take the FITTING they use for the BLB-20 and use it with a double flare in the line, it will work. Notice the length and how the two fittings end. That extra sleeve on the BLB fitting is what pushes and firms up the flre against the female fitting in the hose. I suspect that's the same kind of fitting I would see if I were able to pull mine out in the Fiero. I would not bet on what kind of flare I would find there but I wish it were a standard one.

Beno

ok.....
I just finished pounding the desk and saying "DOH!" about a thousand times.

I just finished plumbing in the new master cylinder for my 12"/13" brake conversion. I went through HELL trying to get all the correct adapters and fittings (yes, finally got it done after stopping by 5 different brake shops).

THEN.....

a few weeks later somebody makes a post of this WONDERFUL website with adapters and accessories available.

At least I know where to find my brake stuff for the next conversion.

You still get a + even though the info is too late for my dilemma.

quote Originally posted by jsmorter1: there is something wrong if the nut doesn't tighten the line down when you double flare it. Double flaring is the industry standard for brake connections involving any type of flares and I have never seen what you are calling a bubble flare

Then you have never worked on Fiero brake lines!
Bubble flares can easily be made by using a standard ISO (In Side Out) or what you are calling a DOUBLE flare kit. I just replaced all the brake lines on an 85 SE using standard 3/16 and 1/4 bulk brake line. You have to drill out the metric nuts to accept the 1/4 inch line. The 3/16 fits without modification. Using a standard ISO flare tool you just don't finish the flare. As long as the bulge you make with the flare tool is centered AND concentric with the brake line it will seal just like the bubble flair. It takes some practice and patience but it can be done without endangering anyone's life.
I have done this on several cars over the past 4 years without a single problem....My 86 SE in my sig is one of them!

In the mid 80's some automotive manufacturers decided to change the long standing design of the brake lines on some of their models. The Fiero was one of those models but unfortunately for us, it didn't catch on so the proper aftermarket brake lines are next to impossible to find. All the Fieros I have worked on have had bubble flares on metric brake lines with metric fittings. I don't know if all the Fieros are like this but I haven't seen any with standard ISO flares and fittings. By the way, when I say metric I mean that the hole through the fitting is made to accept metric lines. The threads may be standard....I don't know for sure since I haven't needed to replace any of them.

Good luck with your brake line project. Let us know how it turns out.

Don
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[This message has been edited by SKIDMARK (edited 04-02-2005).]

So the Fiero lines are the European style? See http://www.fedhillusa.com/pages/709978/

Quote from above link:

Check that the flare is of the correct profile for the components involved. Never use a single 45 degree flare with automotive nuts and fittings.

Automotive brake fittings are always a 45 degree double flare or a DIN (bubble) flare.
A 37 degree flare is acceptable for use with AN/JIC nuts and fittings with FedHill seamless tubing.
Carefully check the thread pitch and diameter of nuts and fittings.

Note that the A1 and M5 (illustration above) look very much alike and will crossthread.
Note that the M1 and P10 (illustration below) look very much alike and will crossthread.

Specifically, the A1 and P10 with 3/8 x 24 threads will thread into a 10MM hole but will fit loosely and probably fail when tightened or in service. A 10MM nut may start in a 3/8 hole but will strip immediately.

Note the lead (non-threaded) portion on M1 and P10. Never use a fully threaded nut in place of a nut with lead. The threads will bottom out so that it feels tight but it's not.

Never use a nut with lead in place of a fully threaded nut. There will not be enough threads engaged.

American and Asian vehicles typically use a double flare. European vehicles may have DIN flare.

Late model vehicles can be any possible combination of nuts and flares. For example a Ford Taurus can have 4 different nuts on the ends of the two rear brake lines!

[This message has been edited by spark1 (edited 04-02-2005).]

Excellent, Spark1, thanks. Where were we when Soelasca needed this kind of reference! I feel you frustration, Soelasca.

Anyway, I knew it was going to rain this morning but I still wanted to give one last try to the existing frozen fitting. I guess one week of PB Blaster adds up because it FINALLY gave! Just then, it started to rain and I had to scramble to put the wheel back on and collect the tools. But I did look closely at the old fitting (too dark to see the old flare).

The old fitting is just like the M1 in the illustration above...which is what the Fiero parts book calls for. I only have new P10 fittings -- taken from the line segment I bought -- the British format next to the M1 pix.

Preliminary impressions - decision time:
-- Now that the old fitting is disconnected, I may simply proceed to put the new hose on. The fitting nut is somewhat stripped but looks usable; it may or may not work well with the original 12mm wrench...adjustable pliers may have to do .
-- If I decide to use a new fitting instead, it seems like I could use the P10 fitting. However, the lead/sleeve seems to be slightly longer than in M1. This may reduce the amount of thread that grabs. I am not sure yet but I don't think it will be much. Also, I need a new flare, and I loose perhaps half an inch of line (I have to cut the old to put the new fitting in). However, it appears safe to use a standard DOUBLE flare.

Since I can't do anything until the rain clouds leave, I'll decide a little later in case some more observations come in.

Beno

I have had the same problem as you folks as I have been replacing all my lines on my project car.

I have found standard to bubble fittings that allow me to convert from a standard flare that I can make with my equipment and attach the fitting that will then seal up against the bubble flare distribution blocks etc. They were not easy to find but I think I have it all figured out now.

I ended up getting them at a parts place called PartSource here in Calgary, AB, Canada but I would imagine NAPA etc. down in teeh States would do the same for you.

Good luck
Don

I went through all that standard to bubble flare stuff last year when I replaced all of the steel lines in Dukie. Yes, it really is different than a double flare. When I made the connection to the proportioning valve up front, I re-used the fittings & carefully made my own bubble by using the double flare tool and not making the final bend. Tricky to make but it worked just fine.

There isn't any problem reusing the fittings/nuts as long as the hardware is in good shape. If the hex on a nut is bad then I would consider the whole nut bad. One because you will have trouble properly torquing the nut and two because you'll have even more trouble next time you have to mess with them.

Anyone that is parting a car would do themselves well to at least salvage any good line nuts even if the lines are bad. Cut the lines and remove the part to where you can take the nuts off without damaging them.

Using the wrong flair or nut is extremely dangerous. You may get the line sealed but you often have a very weak connection and damage the fittings.

As you can see above there are several types of flairs and nuts. If you use the wrong nut with a flair you'll have uneven clamping of the line that will put high strain on the joint. For example: If you put the flat faced DIN nut on the SAE bubble or any cone faced nut on a DIN bubble flair there is a really good chance the flair could blow out with no warning from the poor clamping.

The DIN nut would likely crush the SAE bubble making things even worse. The SAE bubble or a cone nut will only hit the edges of the DIN bubble leaving the center baddly stressed.

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