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-   -   Stress relief coils in brake lines? (http://67-72chevytrucks.com/vboard/showthread.php?t=733244)

siggyfreud 03-20-2017 12:55 AM

Stress relief coils in brake lines?
 
How many of you are bending coils into your brake lines when doing a new setup? I think I got my flaring down, and now starting to run lines. Have gone through about 6' so far that I scrapped. Trying to get my bending down with the tool wherein I don't crimp the line and do a smooth 90*. Using copper.

Was fairly easy to do a stress coil around a can of glass cleaner, but wondered if it's worth the time?

PGSigns 03-20-2017 06:56 AM

Re: Stress relief coils in brake lines?
 
I do them on my trucks.
Jimmy

lolife99 03-20-2017 07:38 AM

Re: Stress relief coils in brake lines?
 
Never add the coils.

siggyfreud 03-20-2017 10:05 AM

Re: Stress relief coils in brake lines?
 
Quote:

Originally Posted by lolife99 (Post 7891450)
Never add the coils.

Can you elaborate a bit? I'm all for saving work, just curious why you recommend it so strongly.

lolife99 03-20-2017 10:13 AM

Re: Stress relief coils in brake lines?
 
I prefer to clean look of well run lines. I see no need for the coils.
If it was a line that was constantly be connected and disconnected I would understand the need.
To me it's like adding coils at the wheel cylinders or any other connection for that point.

Keith Seymore 03-20-2017 12:40 PM

Re: Stress relief coils in brake lines?
 
Quote:

Originally Posted by lolife99 (Post 7891553)
I prefer to clean look of well run lines. I see no need for the coils.
If it was a line that was constantly be connected and disconnected I would understand the need.
To me it's like adding coils at the wheel cylinders or any other connection for that point.

It's because there is relative motion between the cab and frame during use.

The cab is mounted on the body mounts with the master cylinder hard mounted to the cab; the brake lines are hard mounted to the chassis. The cab will move between a quarter and a half inch due to jounce or twist.

Something's gotta give.

No relative motion between the wheel cylinders and the axle tube, which is why the brake lines can be hard mounted to the tubes (the suspension travel is taken up in the center with the rubber hose).

K

cg285 03-20-2017 12:44 PM

Re: Stress relief coils in brake lines?
 
i put them in at the master cylinder. there can be flex in the body to frame which is why they are their. at the rear they are attached to the differential which has no flex.
done correctly they look great AND professional.

using copper is a big no-no unless you are referring to the 90-10 copper/nickel

lolife99 03-20-2017 02:23 PM

Re: Stress relief coils in brake lines?
 
Quote:

Originally Posted by Keith Seymore (Post 7891694)
It's because there is relative motion between the cab and frame during use.

The cab is mounted on the body mounts with the master cylinder hard mounted to the cab; the brake lines are hard mounted to the chassis. The cab will move between a quarter and a half inch due to jounce or twist.

Something's gotta give.

No relative motion between the wheel cylinders and the axle tube, which is why the brake lines can be hard mounted to the tubes (the suspension travel is taken up in the center with the rubber hose).

K

I understand GM's intent on building brake lines to last 40+ years.
(99-06 silverados excluded).
If there's not enough flex in a steel line that drops from the M/C to the frame to keep the steel line from severing on a truck that I drive,... then I will add the coils to my next project or daily driver.

cg285 03-20-2017 03:07 PM

Re: Stress relief coils in brake lines?
 
nothing to do with severing the line

hewittca 03-20-2017 03:25 PM

Re: Stress relief coils in brake lines?
 
Quote:

Originally Posted by Keith Seymore (Post 7891694)
It's because there is relative motion between the cab and frame during use.

K

Without knowing any better, this is always what I assumed the reasoning was, and I believe Keith when he says it. I have noticed, however, quite a few custom builders forgoing the coils for a cleaner look, and always wondered how wise that was. I suppose it's ok if there's at least some bend in the line and not just a straight shot, or maybe they are using solid body mounts...

VictoriaHardware 03-20-2017 05:59 PM

Re: Stress relief coils in brake lines?
 
Quote:

Originally Posted by Keith Seymore (Post 7891694)
It's because there is relative motion between the cab and frame during use.

The cab is mounted on the body mounts with the master cylinder hard mounted to the cab; the brake lines are hard mounted to the chassis. The cab will move between a quarter and a half inch due to jounce or twist.

Something's gotta give.

No relative motion between the wheel cylinders and the axle tube, which is why the brake lines can be hard mounted to the tubes (the suspension travel is taken up in the center with the rubber hose).

K

If you are making custom lines and there is sufficient freedom, coils are not necessary. Steel tubing will bend and twist without harm as long as they are given room. Say the master cylinder-to-frame line is held tight with a clamp to the body down near the frame. If the line is also held tight to the frame not far from the body clamp, then it could be a problem. If the two clamps are spaced further then you're OK. There are lots of vehicles without factory coils.

It also stands to reason that the factory did it for a good reason. If there was ever a chance to shortcut something and save 1 cent, they did it. They also had to design for the WORST case condition for 100K miles, which these trucks are probably not going to see again.

siggyfreud 03-20-2017 08:47 PM

Re: Stress relief coils in brake lines?
 
Quote:

Originally Posted by cg285 (Post 7891699)
i put them in at the master cylinder. there can be flex in the body to frame which is why they are their. at the rear they are attached to the differential which has no flex.
done correctly they look great AND professional.

using copper is a big no-no unless you are referring to the 90-10 copper/nickel

I'm using copper nickel line. https://smile.amazon.com/gp/aw/d/B01...?ie=UTF8&psc=1

See any issues using that?

racecougar 03-20-2017 09:37 PM

Re: Stress relief coils in brake lines?
 
Put me down for the "no coils" camp:

http://i6.photobucket.com/albums/y20...0/P1270400.jpg

Keith Seymore 03-21-2017 08:32 AM

Re: Stress relief coils in brake lines?
 
Quote:

Originally Posted by VictoriaHardware (Post 7891962)
They also had to design for the WORST case condition for 100K miles, which these trucks are probably not going to see again.

This is true.

We also have to accommodate build variation from truck to truck across 1.5 million vehicles, which the enthusiast would not have to comprehend when doing 1 vehicle.

K

cg285 03-21-2017 08:40 AM

Re: Stress relief coils in brake lines?
 
Quote:

Originally Posted by siggyfreud (Post 7892120)
I'm using copper nickel line. https://smile.amazon.com/gp/aw/d/B01...?ie=UTF8&psc=1

See any issues using that?

already stated

abig84 03-21-2017 01:36 PM

Re: Stress relief coils in brake lines?
 
Quote:

Originally Posted by racecougar (Post 7892168)
Put me down for the "no coils" camp:

http://i6.photobucket.com/albums/y20...0/P1270400.jpg

i see nothing wrong with that. even a lot of new cars are doing away with the coils for like a braided section of brake line coming off the master. you just need something for movement of the cab from the frame. you just dont want to right a straight bend going directly down then screwed to the frame that would probably be bad

ryanv70c10 03-21-2017 03:23 PM

Re: Stress relief coils in brake lines?
 
Quote:

Originally Posted by Keith Seymore (Post 7891694)
It's because there is relative motion between the cab and frame during use.

The cab is mounted on the body mounts with the master cylinder hard mounted to the cab; the brake lines are hard mounted to the chassis. The cab will move between a quarter and a half inch due to jounce or twist.

Something's gotta give.

No relative motion between the wheel cylinders and the axle tube, which is why the brake lines can be hard mounted to the tubes (the suspension travel is taken up in the center with the rubber hose).

K


Exactly and the only thing that I would like to add that is every time you hit the brakes, the booster and master will move a bit as well. I am used to unibody cars so I always put coils right below the master

indymachinist 03-21-2017 07:18 PM

Re: Stress relief coils in brake lines?
 
If you don't want to run coils, then don't run coils. But don't try to justify what you are doing by suggesting the coils don't serve a purpose.

siggyfreud 03-21-2017 08:05 PM

Re: Stress relief coils in brake lines?
 
Interesting spectrum of answers here. Given that I haven't heard any negatives in regards to running them, other than perhaps aesthetics, I'll opt to include them in my setup.


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