If a brake line fails, is all brake lost?

Debating if stainless steel lines are worth the cost. Does anyone have experience with brake line failure? Do you lose all braking or only braking in one caliper?

you lose braking on that whole circuit, it usually feels like you have about 10-20% of your normal braking power. not fun, but it'll get you home if you drive like a grandma and be mindful of your stopping distances

On single circuit systems you lose it all(pre ~1967 cars), on a tradition split system(most solid axle rear cars) you lose either the front or rear, on cross split(most modern cars) you lose two opposing corners, which will try to rotate the car if one circuit blows under hard braking. Either split system will only have brakes at the very bottom of the pedal travel, and if it doesn't use a partitioned master, you only have a few stops before you pump all the fluid on the ground. If you have rear drums or cable actuated rear disk calipers you will have a ok amount of stopping power through the parking brake no matter what.

If you want to stress test the system, with the vehicle parked and idling, slam on the brakes hard as you can to simulate a panic stop, any dangerously rusted lines, failing hoses, or screwed up cylinder seals will blow with you safely in the driveway.

The best lines are the copper-nickle type (Cunifer/Nicopp), stronger than steel and easier to work with, and will never rust out. I've never heard of stainless brake lines, I'd think any stainLESS alloy that will hold up to salt would not be strong enough for the hydraulic pressure spikes.

I've had brake line failures happen twice, in a '64 Chevy pickup and a '75 Subaru. It sucked really bad both times. Both vehicles would have qualified for piece of E36 M3 status before each incident though.

GOOD brake lines are worth it, no matter what they are made of.

When you say stainless steel lines I assume you are talking about the flexible lines to the calipers. Unfortunately there is some real crap stainless lines out there. Not all stainless braided lines are the same.

I personally buy from a local hydraulic shop where I know the guys that work there. They make excellent quality hoses that are dot approved, best quality, and cheaper than any oem hose. That plus they make custom AC and power steering hoses with any fittings, curves, or anything I want.

And yeah, brake failures suck. I have stupidly driven junkers home with marginal brakes more than once.

The two line failure that I had were rusty steel lines.

I would be hesitant to use stainless hardlines. Stainless only works in the presence of oxygen to create a protective oxidized coating In an anaerobic environment (such as brake fluid) there is a chance that the coating might never form and what you think are good solid lines (they will look good on the outside) could be rotting away from the inside

As for myself.. I have run braided stainless lines with no problems.. except for a couple of blown brake cylinders over the years

I can tell you that the factory hard lines on a Miata are a very different metal than the mild steel you get at the auto parts store. It's painted and really, really hard to flare. I've never really seen them rust, so I think it's got some sort of stainless properties.

people have been running stainless brake hardlines for as long as i've been playing with cars (25 or so years), an i've never heard of them rotting away or exploding.. in fact, the only issue i've ever heard of with them is that the hardness of the metal makes it a real pain to get the flare to seal right when first installed... but once that's taken care of, they are good forever..

but i think stainless hardlines are a waste of money unless you want to polish them up and have some bling... it took 30+ years of normal driving and neglect to cause most stock steel hard lines to get to the point of blowing out, and it's doubtful that anything with that problem is going to be seeing too many winters full of road salt to eat them from the outside and decades without the fluid being flushed to eat them from the inside..

the only issue with the flex lines is the cost and availability of bolt on lines for a given application. Russel makes some nice ones for some applications that are even DOT legal, if that matters to you..

I will never use steel lines again.

OEM replacement lines are about $130. Stainless lines from an aftermarket supplier are usually $180. No brainer.

I had custom SS lines CNC bent for a project that included a 78 Buick master cylinder, a Wilwood prop valve, 73 C30 front calipers, 98 P30 rear drums, all in a 66 Bonneville for under $300.

Inline Tube and Classic Tube are two companies that make top notch SS brake lines. They CNC bend for a ton of applications, or they can send you lines to your specs.

I've experienced two different brake line failures, both due to rusted lines. Once all your brake fluid runs out onto the ground, which won't take long, your car has just about zero stopping ability except for the emergency brake.

I blew the RF rubber line on my 99 Passat. It wasn't long before the entire contents of the MC was on the ground and I had nothing but the e-brake.

I've had 4 brake line failures. All from rusty lines. "Youngest" was an 8 year old 3rd gen Taurus in the rust belt.

I have been using Teflon coated steel lines up here in the rust belt with great results. there are a weird green color. Bends like steel and does not rust. I got a 25 foot coil of it and replaced all the hard lines in my 94 mustang with it for less than $50

I just looked it up and it is not Teflon it is PVF coated. It is made by AGS. most part stores have it in the back. A roll lists for about $25.

Interesting. SAAB had a split diagonal system back in the '60's and much of the lines were inside the car.

My 66 Caddy has a split diagonal system. The Miata is front/rear. The Land Rover is a single line.

Guess which one has had a failure?

I've lost them in a Taurus and an $10, both due to rust and rot.

The Taurus was "good" I guess, I had to panic stop when someone pulled out of their driveway without looking. I made the stop, but blew the line on drivers rear. Some quick work with vice grips, and I was able to get it safely to my buddies to fix it.

The S10 sucked. It had this problem where the throttle would stick occasionally, and also a problem with the push button 4wd where to get into 4 high, you had to go into 4 lo and then high. Well the right combination of stuck throttle, slick surprise mud, and needing to soft into 4wd broke the line that went over the gas tank, so I never saw a puddle anywhere to know why my brakes sucked. Luckily, the piece of E36 M3 was due for a trip to the shop, so I only drove it around for a day like that. 

I like the copper nickel when I need to fix soaking, but honestly here in the rust belt, blown brake lines mean I'm getting a new car. 

Keith Tanner said:

My 66 Caddy has a split diagonal system. The Miata is front/rear. The Land Rover is a single line.

Guess which one has had a failure?

Weird. My 90 rover had dual lines to every wheel. 

Unless you have a GMT400 and lose the rear brakes, sometimes you won’t even notice. 

Even on a split system, you can potentially lose everything.   Had a serious butt-puckering moment in my '67 Bronco a long time back when I blew out a line going to a rear wheel cylinder and everything went out.  Thankfully I still had SOME emergency brake action, though not much, and was able to find an uphill spot I could get to without hitting anybody.

-Hans

Lost the line to the right front on our Astro eight hours from home after picking up our rescue dog in Jersey. The convenience store truck stop had everything I needed to get home: brake fluid, check; vise grips,  check; zip ties,  check. I cut back the line,  folded it over on itself,  and pinched it shut with the vise grips. Zip tied up in place and drove home on one front and two rear brakes. NP!  The real pain was replacing the line. From the ABS pump along the front chassis leg to the driver side of the radiator,  under the radiator, and back up the the passenger side. That sucked. 

Zombie thread, canoe deleted