My Stainless Brake Line Failed Tonight

[flyboyx]

also, there is less expansion with a stainless line. the brakes will be firmer.

[slammin.e28]

also, there is less expansion with a stainless line. the brakes will be firmer.

This is what I always liked about them. Nice, firm brakes. Feelsgoodman.

[ak-]

We're arguing something that isn't entirely relevant to OP's post - his line broke at the fitting.

My guess is being over torqued. These fittings don't seal at the thread as a lot of you guys know and maybe it was mistakenly over tightened and treated like a nut and bolt.

[reelizmpro]

Are you saying stock lines don't have reinforcement? Have you read the thread I linked to where they cut them open? The OE lines have huge reinforcement and several walls of rubber. They also must pass a 5000 psi burst test after being soaked in water for 70 hours. Let's not pretend that a SS braided line is better than that.

Your lines have an exposed mesh that grabs dirt and grime and grinds it into the teflon. From Stoptech's website:

"Under certain conditions, dirt and other abrasive contaminants can find their way between the SS braid and the Teflon inner hose. Over time these contaminants can be ground into the Teflon line to the point that a leak can develop. Naturally, a leak in the brake system is never a good thing."

In the end, what benefit do your SS lines provide over stock, rubber ones that are just as reinforced?

You can like them better for subjective reasons, or think they look better, but does that make them objectively "better"?

I don't think so. And I believe that the risks associated with them are not worth it when it comes to what is the most important system on your car.

I didn't say stock lines don't have any reinforcement. Yet they still can and do rupture. Rubber when exposed to heat cycles, twisting and bending back without extra external protection can fail. Not so much on E30's but on the E39 there's an intermediate hose that is known to fail causing loss of brake pressure. First you state, no one is running 5, 10 year old lines and I blew that out of the water. Then you quote the abrasion theory and I blew that out of the water. This is first hand experience, not just shit I read on the internet. I do believe they are better otherwise they wouldn't sell so many sets. I can't imagine them making lines that aren't as good or better than OEM. They even make SS braided clutch lines now. The consensus is rubber, even reinforced rubber is still vulnerable to everything I mentioned above and there are better alternatives. For decades many racers have reported less thermal expansion with SS braided lines vs stock rubber.

As pointed out, this thread isn't about a ruptured or leaking line but a damaged fitting.

[Cephas]

also, there is less expansion with a stainless line. the brakes will be firmer.

This is what I always liked about them. Nice, firm brakes. Feelsgoodman.

Yikes. So my rubber brake lines are expanding to the point that I should be able to feel it?

This has been talked about many, many times on other forums. The perceived improvement in pedal feel is the direct result of flushing a braking system that needed to be flushed 15 years prior. The rubber lines are burst tested at 5000 PSI...they are not flexing when you are braking.

Again, from the Stoptech website:

"Any time that an object is subjected to internal pressure, it expands. The amount of expansion will be proportional to the amount of pressure present and the rigidity of the holding structure. In the case of brake hoses, we are subjecting Teflon to internal pressures as high as 3000PSI. Because the Teflon is relatively flexible (which makes it ideal for the job in one regard), it will expand under these conditions. This expansion creates additional fluid volume in the hydraulic circuit which is felt by the driver as a soft or mushy pedal.

Rubber overmolding does little to reduce expansion under pressure, as rubber is also a relatively flexible material. A woven braid of Stainless Steel, however, can greatly increase the rigidity of the hose under pressure while still allowing adequate flexibility for wheel end movement. In many cases, this reduced expansion can be felt by the driver as a firmer or more responsive brake pedal."



Do you know what is inside of a stock OE line? Reinforcement braiding. It is not expanding any more or less than a braided SS line.

[Cephas]

Yet they still can and do rupture. Rubber when exposed to heat cycles, twisting and bending back without extra external protection can fail. Not so much on E30's but on the E39 there's an intermediate hose that is known to fail causing loss of brake pressure. First you state, no one is running 5, 10 year old lines and I blew that out of the water. Then you quote the abrasion theory and I blew that out of the water. This is first hand experience, not just shit I read on the internet. I do believe they are better otherwise they wouldn't sell so many sets. I can't imagine them making lines that aren't as good or better than OEM. They even make SS braided clutch lines now. The consensus is rubber, even reinforced rubber is still vulnerable to everything I mentioned above and there are better alternatives.

As pointed out, this thread isn't about a ruptured or leaking line but a damaged fitting.

At the end of the day, a website for a company that wants people to believe in SS lines is what I'm using as my reference point and they are the ones that say that abrasion can be an issue, so much so that they say they should be inspected more frequently. At the end of the day, would you argue the point with stop tech?

I'm glad you've had success with your lines. Others, as in this thread and the linked one, have not. Something to take into consideration.


ARTFOODBMW - sorry about your line and glad that you weren't hurt!

[reelizmpro]

Finally some numbers. Can we put this baby to bed?

[SkiFree]

We're arguing something that isn't entirely relevant to OP's post - his line broke at the fitting.

My guess is being over torqued. These fittings don't seal at the thread as a lot of you guys know and maybe it was mistakenly over tightened and treated like a nut and bolt.

This x2. This fitting was over-torqued plain and simple.
------------------------------------------

And just as a data point Cephas, I work around a couple 911 GT3R's, and a half dozen GT4Clubsports (among other cars). The stainless PFC lines they use are NOT replaced "more than every oil change". They are inspected, yes, but they are changed once a season or as the hours max out (whichever comes first).

You mention "associated risks" of aftermarket stainless lines, but the reality is that there is an equal amount of associated risk with most plain-old aftermarket rubber-lines. There are OEM-quality lines and equally-good-quality SS lines (like Spiegler/Brembo/PFC).

When comparing equal-quality stainless and rubber lines, the advantage of the stainless is road-debris protection and it does a better job of fighting swelling when the line heats up (I've seen race data showing EXACTLY this. It does reach the point of making a difference on a canyon-carving E30). But, I agree, for most street-driven e30's the point is moot. In the end, buy quality.

[Matt-B]

I bought SS brake lines for my e36.


I guess it was nice knowing you guys.






whats worse, buying an F30, or gambling your life on SS lines.
Discuss

[reelizmpro]

OK, you seem more invested in "blowing me out of the water" than having a conversation about potential issues.

At the end of the day, a website for a company that wants people to believe in SS lines is what I'm using as my reference point and they are the ones that say that abrasion can be an issue, so much so that they say they should be inspected more frequently. At the end of the day, would you argue the point with stop tech?

I'm glad you've had success with your lines. Others, as in this thread and the linked one, have not. Something to take into consideration.


ARTFOODBMW - sorry about your line and glad that you weren't hurt!

You made two general statements that are flat out wrong. If I were an aftermarket brake company like Stoptech, I'd tell you the same thing to sell more lines or pass on liability. Now they can say, hey we disclosed potential issues and lines should be inspected often, whatever happens is now on the customer. You have to look at where they are coming from.

[jeffnhiscars]

We had a 2004,5,6 (don't remember) Peugeot 206 convertible in Mexico that had a rear rubber brake line fail in under 2 years and 10,000 kilometers.

Manmade things fail.

Saying "Peugeot" loses,95% of this crowd...said as someone who owned a 59'Peugeot 203 :)

We're arguing something that isn't entirely relevant to OP's post - his line broke at the fitting.

My guess is being over torqued. These fittings don't seal at the thread as a lot of you guys know and maybe it was mistakenly over tightened and treated like a nut and bolt.

Exactly !! This is not a "line failure" but rather a metal fracture. that hose did not separate from the ferrule or blow out so,has nothing to do with SS or rubber or a hose made from moose droppings.

I hate to quote jlevie cause we all know he doesn't know shit from shinola, but he doesn't use SS brake lines cause they have a habit of coming apart....not that that's what happened here but since everyone is talking about that, I'll be the fly in the ointment (geez I'm dating myself. lol stop now)

[LJ851]

My understanding about stainless braided brake lines is that they don't generally give an external, visual indication that the line is about to fail. They just fail.

Rubber lines generally give external,visual signs of distress before they fail which some people feel more comfortable with.

All of this has nothing to do with OPs post with a clearly deformed and broken metal fitting.

[Das Delfin]

If these lines were made as cheap as possible (being aftermarket), the fitting could be made from an inferior metal and be more susceptible to shearing/fatigue.. Wish we knew the wholesale cost compared to other SS lines

[AwakenNoMore]

I had a stock line fail on me a few years back, installed these exact lines in their place. No complaints or worries here. I don't see how this could happen without something physically yanking them out.

[TobyB]

Ever seen a 5 year old stainless line on a car?

err...yes... now that I think about it, the 2002 race car's were new in 2004...

...and I did those on the Datsun roadster in about... 1995...

In practice, a teflon- braided hose does deflect a bit less under pressure than a rubber hose.
It can also be good to much higher ultimate burst pressures that don't matter at all
(an E30 makes 2000 psi with a brute using both feet on the pedal- wheels lock at less than 1000, with street pads and tires)
Yes, I've done an apples- to- apples fresh fluid and fresh hoses test, on a 2002.
It also doesn't rot and seal up after 20 or 30 years, like the 2002 version does.
I bet we're about due for a round of that here in E30 world.

Does it matter on a street car? Not much.
Are you going to die if you do it?
Probably not. But maybe. You might also die
from a cheaply- made rubber knock- off, too.
There is some merit to buying the factory hoses-
IF those aren't made cheaply in China by a 3rd party,
then sold to "BMW Tradition" or whatever they're
calling themselves now...

t
not worried.