Brakeline coils under master cylinder

[69importkilla]

So you know how the factory coils the lines two or three times underneath the master, are they necessary? I'd like to make them straight just to clean it up a bit.

Also how should I flare? Double or single?

Thanks!

[Apogee]

45 degree SAE inverted (double) flares are the preferred connection in most brake systems. As for the coils, they are there to serve as strain reliefs for the hard brake lines so that they don't crack due to the relative motion between the chassis and the body. You can bend your lines in a straight manner to serve the same purpose if you prefer, it's just not usually as effective. If you're running solid body mounts or something along those lines, the relative motion is greatly reduced and it probably won't be an issue either way.

Tobin
KORE3

[EFI69Cam]

On a stock car with rubber subframe mounts the body would move with respect to the frame so a factory put those there to provide flex. They also keep the brake lines from breaking in an accident and possibly causing a fire. I kept them on my car.

[CarlC]

Stainless lines only require a single flare.

[69importkilla]

Thanks, SS is what I'm running now

Ok then I guess I just have to find a way to make them look "better".

[wmhjr]

A couple things.

Modern cars do not have those loops any longer. I've seen and done plenty of older cars without those loops and I'm still waiting to see the very first one that has an issue. Look at where the deflection of brake lines in the system really happens. Back at the rear end when it articulates - which is why there's a flex line. Front brakes - which is why there are flex lines. The hard line deflection is most likely to happen in the center of the body in a perimeter frame or a unibody car without a chassis under it. Those coils up front do nothing to assist with those. Obviously YMMV, and you should exercise caution in planning how to route your lines, but I would never put those loops back in. Never have, never will.

Also, using stainless line does not eliminate the preference for a double flare. Double flares are the correct way - though they are harder and will likely require a hydraulic flaring tool.

Just my 2 cents.

[EFI69Cam]

A couple things.

Modern cars do not have those loops any longer. I've seen and done plenty of older cars without those loops and I'm still waiting to see the very first one that has an issue. Look at where the deflection of brake lines in the system really happens. Back at the rear end when it articulates - which is why there's a flex line. Front brakes - which is why there are flex lines. The hard line deflection is most likely to happen in the center of the body in a perimeter frame or a unibody car without a chassis under it. Those coils up front do nothing to assist with those. Obviously YMMV, and you should exercise caution in planning how to route your lines, but I would never put those loops back in. Never have, never will.

Also, using stainless line does not eliminate the preference for a double flare. Double flares are the correct way - though they are harder and will likely require a hydraulic flaring tool.

Just my 2 cents.


That could be true about the deflection in normal driving, but in a collision all bets are off as to whether or not parts are going to stay in their relative positions or not. Being trapped in a car is bad enough, worse if its on fire and anything that can mitigate that risk to me is worth it.

Also I seem to recall that my 2003 Suburban has loops, maybe the decision is made based on body on frame vs. unibody design?

Just my 2 cents.

[prostreet69camaro]

I agree ,,double flare but a real pain to do with SS.

[novaderrik]

A couple things.

Modern cars do not have those loops any longer. I've seen and done plenty of older cars without those loops and I'm still waiting to see the very first one that has an issue. Look at where the deflection of brake lines in the system really happens. Back at the rear end when it articulates - which is why there's a flex line. Front brakes - which is why there are flex lines. The hard line deflection is most likely to happen in the center of the body in a perimeter frame or a unibody car without a chassis under it. Those coils up front do nothing to assist with those. Obviously YMMV, and you should exercise caution in planning how to route your lines, but I would never put those loops back in. Never have, never will.

Also, using stainless line does not eliminate the preference for a double flare. Double flares are the correct way - though they are harder and will likely require a hydraulic flaring tool.

Just my 2 cents.

how many modern cars have a full frame with soft rubber bushings between it and the body?
they put those loops in for a reason- if they could save a few pennies per car by leaving them out, they probably would have.
i've found that the loops make it easier to hook the lines up if you change the master cylinder, and they allow you to remove the master from the brake booster and flip it out of the way to remove the booster without cracking open the system.

[wmhjr]

That could be true about the deflection in normal driving, but in a collision all bets are off as to whether or not parts are going to stay in their relative positions or not. Being trapped in a car is bad enough, worse if its on fire and anything that can mitigate that risk to me is worth it.

Also I seem to recall that my 2003 Suburban has loops, maybe the decision is made based on body on frame vs. unibody design?

Just my 2 cents.


My 2000 silverado and my 2004 Dodge Ram, as well as my 2008 Mercedes have no loops. The first two are body on frame. The last is unibody. As for a collision, I seriously doubt that those loops would be the one thing that would prevent a fire in the event of a collision, but that's just me.

[wmhjr]

how many modern cars have a full frame with soft rubber bushings between it and the body?
they put those loops in for a reason- if they could save a few pennies per car by leaving them out, they probably would have.
i've found that the loops make it easier to hook the lines up if you change the master cylinder, and they allow you to remove the master from the brake booster and flip it out of the way to remove the booster without cracking open the system.

Lots of them. Like I said, many MANY new vehicles including trucks which are body on frame with bushings between the two no longer have those loops. Believe me, I'm VERY familiar for example with the braking systems of the 99+ GM trucks. If you're familiar with my (now gone) POS Silverado, you know that I had to replace every single line in the vehicle. There was never, ever a single loop in that brake system from the day it was built at the GM plant on.

Like I said, I don't care if people put them in or not. But I have yet in 35 yrs seen a single problem resulting from removing them, and many new vehicles no longer have them.

BTW, remember that the big 3 also put those loops in unibody cars. So we shouldn't be just basing our opinions on perimeter frame cars.

[CarlC]

Also, using stainless line does not eliminate the preference for a double flare. Double flares are the correct way - though they are harder and will likely require a hydraulic flaring tool.

Can you please explain the need for a double flare on a stainless tube?

[wmhjr]

Can you please explain the need for a double flare on a stainless tube?

I'm not sure what you're asking. Why would you believe that by using stainless you would need a different flare? Personally, I think the stainless=single flare idea was started because it's friggin difficult to double flare stainless, and because many people used thick wall stainless. Take a look at stainless lines you buy pre-made. Are they single or double flare? They're double flare. 45deg double flare. 37deg single flare is AN. My understanding is that the correct way to do stainless hard brake lines is thin wall, seamless stainless, double flare 45deg.

Mastercool has made tons of money off of people doing stainless lines that double flare.

[silver69camaro]

Double flares are needed on 45 degree flares, regardless of material, to prevent cracking by the nut galling the tube material. If you think about it, the sealing surface is not the same tube wall as the nut surfance (same with bubble flares). These are technically a one-time use flare, as the flare is permanently deformed as the nut is tightened. Each re-fit will require more deformation and torque for a proper seal.

And again, technically, a 37 degree flare does not need a double flare because of the seperate nut and sleeve. The sleeve seperates the galling action on the tube wall to the sealing wall.

It's been a long time since I had to research that stuff, so somebody correct me if I'm wrong. And I'll admit I use double flares on 37 degree stuff, only because I have a tool that can do it nicely.