hard line coils

[absintheisfun]

I have been told that the reason for the coiling of the hard lines below the master is so there is some flex in case there is shifting/movement. Personally, I think it is pretty fugly--can a braided soft line be used to run the lines along the firewall with a little extra slack for the shifting/movement?

If I have been told wrong, what is the reason for the coiling of the hard lines below the master?

[73z-6sp]

I've wondered if that was the reason also. My take is that even if it is true...they don't need to be excessive. Simply adding some extra length in the shape of a "7" would give some play for a small amount of flex. Now, if it comes into play during a collision...I can see the longer coils being beneficial. But honestly, if you're in a collision is it going to matter much? Especially one strong enough to displace the frame from your car?

[oestek]

The concern is that the high-pressure brake lines will shear in a collision, spraying fluid on hot exhaust under high pressure (assuming you're on the brakes on impact) and cause a fire. I'm not an engineer and don't know the federal safety requirements, but it does seem to be excessive to have 3 - 4 coils. However, it seems they would stretch out and keep the system closed on a significant impact.

[MrForce]

It is my understanding that coils are the most resistant to vibration that can lead to cracking.

[oestek]

It is my understanding that coils are the most resistant to vibration that can lead to cracking.

That too.

[DynoDon]

Seem to remember learning in Auto Shop (35 years ago) that it was to alleviate Hydraulic Shock, especially under fast quick loading like a panic stop

[novaderrik]

probably not a primary design consideration, but they also make it so that you can remove the master cylinder from the booster and set it out of the way so you can change the booster out without cracking open the brake system.

[wmhjr]

As an aside, just know that many new cars no longer have those coils in the brake lines. This has been a topic of a number of threads, and let's just say there is not necessarily complete agreement as to the real engineering advantage/disadvantages. Every "new" vehicle I currently own has zero "coils" or "extra line" in them from the factory. And before jumping to conclusions, that includes both full framed and uni-body construction vehicles. As for the fire hazard issue, maybe so. However if that's the case, my Silverado had hard line fuel lines at pressure right next to the brake lines (which had no coils, btw). There is nothing preventing fuel from displacing on exhaust after a rupture. The coils on the brake lines do zero to help further back on the frame since they are secured to the front frame/cowl in most vehicles anyway.

Do what you want with the info. Braided stainless flex lines might be OK, but are probably more prone to an issue than just making neater brake lines without the coils. JMHO.

[H2Ogbodies]

I concur with dynodon on the hydraulic shock concern...besides newer cars have ABS which negates the need for the coils.

[wmhjr]

besides newer cars have ABS which negates the need for the coils.

Interesting comment. Care to elaborate?

[sebtarta]

There was a thread about this not too long ago

https://www.pro-touring.com/forum/showthread.php?t=71083&highlight=coils

[absintheisfun]

Okay, I am in Auto Tech school on page 857 in the book we are using it states, "The coils in the brake line help prevent cracks caused by vibration.

I have been paying attention to the masters on the vehicles we have been working on and it does appear that newer ones are not coiled, but do have extra bends or "u" s in the lines. I guess it still serves the same purpose but with less line.

[wmhjr]

I would agree with that. I think most of us running new lines different than OEM are also adding things like prop valves, maybe line locks, etc. I have a number of bends in mine and there is plenty of opportunity for the lines to deflect without putting strain on them - or at least as much as that's possible with hard stainless.

I also know that there were no extra "U's" or bends in the brake lines for my '00 Silverado. The lines were routed based on where they needed to go and obstructions. Ask me how I know... wait - please don't ask. I'm trying to forget.

[gort69]

Per JohnZ over at Team Camaro, who worked on the line when the first gens were built, the main reason for the loops was ease of assembly on the line. The brake lines/MC were part of the subframe assembly, and the loops allowed flexibility when marrying the subframe to the body. I believe him. http://www.camaros.net/forums/showthread.php?t=31006&highlight=loops

[MrQuick]

Per JohnZ over at Team Camaro, who worked on the line when the first gens were built, the main reason for the loops was ease of assembly on the line. The brake lines/MC were part of the subframe assembly, and the loops allowed flexibility when marrying the subframe to the body. I believe him. http://www.camaros.net/forums/showthread.php?t=31006&highlight=loops
yep, I remember seeing an assembly line photo and it showed the master, lines connected and on the subframe assembly The booster was on the body which was 5 feet above the subframe assembly. Can't seem to find it. This would support your explanation.

Vince

[MonzaRacer]

OK lets set it straight, its cheap, its easy to have done during production and it decreases flex cracking.
Now as for braided steel , yes you can use them, Ford does this in many of its vehicles including trucks, And I have even removed them for regular hard line in pinch when repairing vehicles with rusty lines.
I do know its does keep stainless brake line s from breaking as easy.
Helped a guy do some on a street rod, it cracked 6 flars at master cyl, after we found small auger in my grandfathers scrap pile to wrap it around for a nice spiral he has never broke a lien again.
Goodridge should be able to whip up a suitable flex line with appropriate ends, or possibly a custom bike shop that can do DOT/VMSS crimps or order them.

[JRouche]

...besides newer cars have ABS which negates the need for the coils.

What?!?!? How is that? JR