Anyone agree with this?
quote 1:
Yeah...my one comment is stainless lines are mostly crap compared to the stock ones. There's no difference in feed, they don't fit as well and I don't believe they're nearly as durable as stock lines. I've been through many stainless lines. The Goodridges are probably the best but, even there, the fitments not nearly as good as stock.
anoter quote:
The ones Bimmerworld sells are tested to 3000 PSI and I suppose meet the 325 lb pull and water soak tests but, the stock BMW lines meet the same requirements. Maybe you have magic feet but, I can't tell the difference between stock and stainless. The stock lines HAVE internal braiding that's actually thicker than the braiding on any stainless lines I've taken apart (or in one case examined when an end fell off).
Quote:
S5.3.2 Expansion and burst strength
The maximum expansion of a hydraulic brake hose assembly at 1,000 psi and
1,500 psi shall not exceed the values specified in Table I (S6.1). The hydrau-
lic brake hose assembly shall then withstand water pressure of 4,000 psi
for 2 minutes without rupture, and shall not rupture at less than 5,000 psi
(S6.2).
http://www.access.gpo.gov/nara/cfr/w...cfr571_04.html
Basically what this says is that ALL dot lines have to meet the same minimum expansion tests. Which means the ads that suggest that stock lines are spongy and that the stainless lines are so much better, might just be bullshit.
Maybe there are good ones out there but, I've not seen any that fit as well as stock or felt any better.
Last edited by jcrist; 06-27-2010 at 09:10 PM.
whatchu got
I replaced my VERY old rubber lines with SS ones back about a year ago. I would agree they don't fit as well but I haven't had any issues with them (Goodridges) and I would say that pedal feel is possibly nominally improved. They look good under the car though, but thats not really worth too much.
-Ryan
1993 325is racing car type thing....
Nonsense. Shiny braking components give you +10 negative horsepower. They are like antistickers.
I noticed no measurable difference between the braided steel and the stock rubber. I replaced them because I was refreshing the braking system completely when I first got the car, they're cheap and the original lines were dead… so why not?
"I hate to advocate drugs, alcohol, violence or insanity to anyone, but they've always worked for me." - Hunter S. Thompson
Suspension Overhaul FAQ
I went with stainless steel brake lines when I had my 930, and now with my BMW. You can sqeeze OE brake lines. That was all I needed to know.
JCrist! I run. The SS lines because I am worried about the heat on the braking system melting the stock rubber ones! I feel that the SS lines give you a firmer feel after the brakes get warm! I would never run a stock rubber set! Ialso feel that the rubber ones could be damaged easier if you run something over! On a race car I feel you should always run SS lines!
Last edited by T Smith; 06-27-2010 at 11:04 PM.
i've seen two race cars with recent, high quality aftermarket SS brake hoses suffer catastrophic failure resulting in high speed offs (fortunately no injuries). yet i've never seen stock hose, regardless of age, fail. as for feel, the best brakes i've ever felt in my life were on my nsx (it had rotor problems but that's another issue) and it had stock 20yo brake hoses. obviously that's just one data point so take it with the usual grain of salt. but consider, how many e30 and e36 owners complain about a comparatively soft brake pedal despite the addition of SS hoses?
personally i am not convinced that SS brake lines are "better" than stock, either with improved durability or reduced elasticity. having worked as an automotive engineer for nearly ten years i'm very familiar with the huge amount of testing that goes into oem products, and that goes double for safety items. i'm not suggesting that oem parts are always better than aftermarket (the e36 water pump comes to mind) but the whole "SS brake hoses are better than stock ones" feels to me like an urban legend that persists just because it looks true.
Last edited by jtower; 06-27-2010 at 10:50 PM.
Last edited by Ranger1; 06-27-2010 at 11:27 PM.
Stock E36 M3 lines don't. I just cut some up tonight because I was wondering too. Under the outer layer is a thick section of fabric braid which covers an inner rubber line. S2000 lines have internal metal braid. It's right under the rubber coating. I haven't chopped up an NSX line to tell myself.I am not about to cut my brakelines apart to determine this, but I thought that stock rubber hoses have a metal braided line inside of them.
There was a guy killed at Summit when his stock brake line failed 2-3 years ago. I know another guy who's Stoptech line failed on the front of his car and he went off turn one and totalled his car at Summit main again (that's where I normally track) My problem with aftermarket SS lines is mainly fitment. Numerous times, I've seen where there was simply too much slack in the lines or the grommet didn't fit and the line was hit by the wheel weight and cut or cut by rubbing on the wheel. I've also had the ends pop off on a set some years ago. It was a store brand (not goodridge or stoptech) but, still it was eye opening. I could have been on track when it happened.
DOT requirements are 5000 PSI burst pressure, 325 lb pull test in the line to make sure the ends don't come off. They have to soak in water 70 hours and still meet the 5000 PSI test. They have to be chucked into a machine and whipped back and forth many times without the end failing. All the SS lines I've seen/installed seem flimsy compared to the stock lines.
I'm simply of the opinion, from looking at the lines, that the stock lines are a better quality than any aftermarket line I've looked at. I can't feel the difference between stock and stainless when I brake, on the street or on the track so, other than as a blingy thing, I don't see any reason to run SS lines.
I believe if you track, you probably ought to be replacing your lines every couple years. Seeing brake lines fail on track has sort of spooked me.
http://www.access.gpo.gov/nara/cfr/w...cfr571_04.htmlS5.3.2 Expansion and burst strength
The maximum expansion of a hydraulic brake hose assembly at 1,000 psi and
1,500 psi shall not exceed the values specified in Table I (S6.1). The hydrau-
lic brake hose assembly shall then withstand water pressure of 4,000 psi
for 2 minutes without rupture, and shall not rupture at less than 5,000 psi
(S6.2).
This is the information I dug up on DOT requirements. All lines are required to meet certain expansion limits under pressure. I don't actually know though if these are the most current requirements.
Last edited by MasterKwan; 06-27-2010 at 11:31 PM.
We had a guy go off at Blackhawk Farms Raceway (pretty hard track for brakes) when one of his stainless, non-DOT approved mind you, lines pulled out of the fitting!! Totalled the car. His new car has braided, but these are DOT approved from a different manufacturer.
All my cars that go on track or that have been driven aggressively have had braided steel lines installed. They seem to make a bigger difference when replacing older lines.
Feff
Heat plus pressure. Rubber lines flex 66% more than most stainless. MasterKwan, you can soak them in water all you want but the DOT tests don't include the heat generated by race driving. Its beyond wrong to compare a race ready stainless line to a rubber own and this thread will bear that out.
JTower, I'm disappointed.
whatchu got
you will be much less likely to damage any brake line by not allowing the weight of the caliper to be supported by the line. many brake jobbers do this and you can see the pull stress on the ends is not straight. it looks more like a prying motion. i think as long as stock lines don't look deteriorated from age, keep them. if it's time to change, i like the stoptech products. they feel good, route correctly and are DOT legal. my experience with ST lines is only on e36's with and without dig brakes.
David Ortiz
Re. steel fibers vs. other fibers. There's nothing inherently superior re. weaves of stainless steel. There's lots of non-metallics that have higher tensile strengths then steel. The design of the weave counts for a lot. My point is that we can't look so much at what the brake line is made of, nor how it's made. The only thing that really counts is test data.
But getting unbiased and comparable test data might be tricky.
I don't know why the brake lines would get all that hot. They get a lot of air flow and have a helova lot of surface area for a small volume. Only time they should get really hot when someone doesn't do a cooldown and then parks.
Last edited by Ranger1; 06-28-2010 at 09:53 AM.
You know, you make these claims but, don't back them up with any kind of proof whatsoever. So far all you've done is say "they've GOT to be better". Maybe you're right but, do you have any kind of testing to back it up? Having a DOT number just means they're at least as good as stock lines. Not better.Heat plus pressure. Rubber lines flex 66% more than most stainless.
I'd like to see the testing you've apparently seen that shows the temp problems with stock lines? The stock lines are Rubber outer, thick cloth braided liner and rubber inner (probably not REALLY rubber). The cloth is what makes them pressure resistant. So, it's not like you can claim the rubber getting soft makes them expand. I have a hard time believing you've had an OEM line in one hand and a stainless in the other and said "well this SS line looks much better made".
stock rubber lines arent just floppy rubber. Most are reinforced w/ aramid yarns, kevlar and/or metal. You cant compare a 15 year old rubber line to a new one. A new one, alongside a SS line should have similar performance.
People replace 15 year old equipment w/ new SS lines and all of a sudden are like OMG!!!!! WHAT A HUGE DIFFERENCE!!!!!!
I've wondered the same thing, I raced on stock lines (20 year old lines) for quite some time and eventually upgraded to stainless. The feel didn't improve at all and if anything I thought the stainless were more likely to get kinked and worn over time. Interesting thread.
Simon
Spec E30 #116
I never felt any difference going from old OE lines to SS lines, just the fact that I "thought" SS lines were better is why I buy them.
Exactly right and that was the likely cause of my SS line shearing off the caliper last fall in VIR T1.
I have no data and am aware of no testing on this subject, so in cases like this I defer to the people who know the most. What do race teams run? We know Bimmerworld uses SS lines. What about Turner, Fall Line, etc? Instead of playing armchair engineer, I will go with what these folks do.
I run SS on my car, but not because they are "stiffer" or have burst strength numbers or whatever useless DOT stamping and marketing is put on them.
SS lines are way cheaper than new OEM rubber ones and the sheath does offer some level of protection. Some SS lines are also smaller in diameter which helps w/ feel.
Stainless steel lines should be better than stock. The teflon hose withstands pressure and temperature far better than rubber hoses for sure, that's why it's used so extensively on aircraft. The stainless steel braid isn't to help it withstand pressure, the teflon hose does that very well already, it's for abraision resistance. As far as the materials go, stainless lines are far better than rubber. I think the problem with stainless steel lines is the quality of manufacturing and lack of good fitment. If the ends are not properly attached, the hose can come out. You'll never find a teflon hose where the hose failed (except for external abraision), it's always at the fitting.
I've had several stainless lines fail as well. In once instance, the line got caught up over the rear axle output shaft on my M Coupe and wore through. I'm not sure if the stainless line was longer than stock and hence was able to get up there. Or, possibley because I was at Lowes Motor Speedway (a NASCAR track) with steeply banked turns, I wonder if the suspension compressed more than usual alowing it to get caught up there and it would have happened with OEM just the same.
I've also had two lines pull apart at the fitting on separate ocaisions. That's a manufacuring defect for sure, especially since they were both made by the same company and that company has since changed the design of their lines, hopefully correcting the problem.
This could be the law of numbers. Perhaps there are much fewer race cars running OEM brake lines.
-Page
This is my fitment complaint in a nutshell. You can make the SS lines fit but, you can't assume they'll route the same as the OEM lines. You have to install them, compare the routing and the mounts and then make sure they'll stay in place and that the amount of slack is correct. I always find I have to either adjust the SS lines and/or add additional strapping to make sure they stay routed properly.I've had several stainless lines fail as well. In once instance, the line got caught up over the rear axle output shaft on my M Coupe and wore through. I'm not sure if the stainless line was longer than stock and hence was able to get up there.
I have SS lines on my M3 so, I'm not just talking theoretical. The ends aren't as beefy, the fitment isn't as good. They were cheap though. I had to add a strap to the front lines because the grommet that holds them to the strut is simply the wrong size. I'll probably be switching back to OEM in 2-3 years when I replace these lines again.
You know, you could say the same thing about the balljoint boot on the LCA and tie rod but, mine doesn't melt because I still have my backing plate. Still on cars I've tracked that didn't have backing plates, I never melted the tie rod boots, balljoint boot or rubber brake lines. I have heard stories of it happening though.Radiant heat transfer from the ~1,000* rotor a few inches from the hose.
It depends on the quality of the OEM rubber lines.
Go look at a Porsche 993 Cup race car. Rubber lines. Most people with 993 race cars just run the OEM rubber lines. They don't fail. I'm not sure about 996 race cars but I wouldn't be surprised to see rubber in there too.
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