Stainless braided flex lines are always "better" than rubber flex lines. The whole purpose of braided lines is to reduce the amount of expansion in the hose under pressure. Less expansion means greater pressure available to act on the caliper. Of course you can't always use braided flex lines in every situation because there are minimum bend radii that must not be exceeded. Braided lines are usually made of a Teflon tube that has its limits of flexibility before it kinks and collapses, and once it does that, it's toast.
i guess i just see all the posts where the braided lines leak over a couple of years and no problems with a rubber unless is pops or ruptures when you do a search it doesnt happen very often. i have had the car 18 years and plan on keeping it for a while more it is my first car when i turned 15.
i guess i just see all the posts where the braided lines leak over a couple of years and no problems with a rubber unless is pops or ruptures when you do a search it doesnt happen very often. i have had the car 18 years and plan on keeping it for a while more it is my first car when i turned 15.
My braided lines have been on mine since 1998. They have been through two brake system upgrades. Currently been on there with my 12" brakes since 2001. I have had no leaks yet... But I check them regularly.
-Dave
Adding:
Mine were custom sized for me, and they do not use Banjo fittings. They are not DOT approved. They are Aircraft grade with custom Teflon outer shields where needed, but mostly exposed SS braids. There are 8 of them on my car (the brake biasing valve is under the dash).
[This message has been edited by IFLYR22 (edited 07-07-2013).]
My recommendation is to use OEM-style rubber hoses unless you have a specific reason not to. See this archived thread for a good discussion of the issues.
I have SS braided lines on four vehicles at the moment and have not had any problems. The oldest system has had them for about six years and the remaining ones from five to four years without failures.
I understand the concern raised by Ogre and Marvin, though I wonder if this condition is a real or hypothetical one. I've been driving my 308 kit with stainless braided lines since 1996. The thought that the braids could break and wear into the Teflon inner tube never crossed my mind. In real world conditions, the suspension flexes very little, and lock-to-lock movement of the steering wheel doesn't flex the hoses beyond the elastic range of the individual steel strands making up the braid as long as the proper length is chosen. I suspect the biggest problem with stainless braided lines is that it may be harder to inspect the condition of them as compared to their rubber equivalents.
I just installed Russel DOT approved lines. They have no covering over the braid which I am not so sure about, they are brand new though, shipped to me directly from Russel. I installed mine with large radii bends, and in the rear I changed the angle of the bracket where the hardline hooks up to the hose so that it was not making a 180 degree bend, now it is more like a 140 degree bend and a big one. I used cushion clamps I bought from summit (also made by Russel) to hold the brake lines in place, front and rear. At full droop in the rear there is no chance of kinking, and up front I gave a little extra slack to compensate for turning the wheel. I am not worried about a failure from anything but sand getting into the braid. I may call Russel to ask about it.
Also my friend's Dad's Fiero has had ss hoses since the 80s on his 84, custom hoses though. The car has driven a touch past 100 000 miles, and was garaged for around 6 years until 2009, and has been garaged again since 2011 till the present. He has had no failures.
"Rubber" really isn't "rubber". OE style hoses have rubber inner liners and outer sheaths, but they have steel braid inside the rubber also.
Remember that brake line pressures in a panic stop can get to ~2,000 psi (well... maybe not with the Fiero booster, but in general...). There's no way that rubber on its own would hold that pressure.
This means that there's no advantage in "pedal feel" in going from a rubber line to a braided stainless line.
OE style lines can take more trauma before failing, survive more environmental exposure and more grit, wear and contamination than braided SS lines.
I have OE style lines on my car with LeBaron/Caddy front brakes and Pontiac 6000 HD fronts in the rear. My pedal is high and solid... Only thing I've ever driven that has better brake feel are my dad's '70's Jaguar XJ6's... and they have cast aluminum pedal boxes with compound leverage on the brake pedal as well as cast iron 4 piston calipers.
I understand the concern raised by Ogre and Marvin, though I wonder if this condition is a real or hypothetical one. I've been driving my 308 kit with stainless braided lines since 1996. The thought that the braids could break and wear into the Teflon inner tube never crossed my mind.
At this point I will disclose that I, too, have PTFE/stainless brake hoses (from Russell and Earl's) on my Formula ... but I have specific reasons, one of which is R&D. People who, like you, have cars with a substantially wider track than stock are also likely to need longer brake hoses than the OEM parts. The '88 rear brake hose arrangement I posted pictures of in this thread, using 15-inch Russell hoses, has been working flawlessly on my Formula since 2006. YMMV.
Good -- Installation with the suspension at normal ride height. Note the generous bend radius that distributes flexing along more than half of the hose length:
Acceptable -- Detail of hose bend at maximum suspension droop:
quote
I suspect the biggest problem with stainless braided lines is that it may be harder to inspect the condition of them as compared to their rubber equivalents.
I'm not a hose engineer, but I'm beginning to conclude that minimum-bend-radius violations are at the root of many braid-puncture failures in PTFE/stainess brake hoses. This can be due to poor design, simple disregard of minimum bend radius specifications, or a too-short hose getting pulled tight at full suspension droop ... e.g. when the cars is jacked off the ground. IMO, the Earl's PTFE/stainless hose kits that The Fiero Store used to sell were too short in the rear and could easily be bent tighter than the minimum bend radius specification for that hose material. The Earl's hoses lacked a protective outer jacket, so abrasive dirt and grit could get down into the stainless braid, and they also lacked strain relief provisions at the end fittings.
Unacceptable -- Detail of bend radius of TFS-supplied hose at maximum suspension droop. Note the lack of an outer jacket to protect the braid and lack of strain relief at the end fitting :
Inspecting PTFE/stainess hoses for braid fraying is relatively easy. Fold a shop rag a couple of times, and then lightly "wipe" the entire length of the hose with it. This is the inspection method commonly used in aircraft practice, and any external fraying of the braid will grab the rag. Don't try this without the shop rag, though, or you are likely to wind up with painful puncture wounds in your hand.
quote
Originally posted by zkhennings:
I just installed Russel DOT approved lines.
Rather than "DOT approved" we should be saying "DOT compliant." For those who don't already know, DOT does not "approve" anything. DOT writes the standards, and each manufacturer is then responsible for certifying that their own products are in compliance with those standards.
quote
Originally posted by Will:
OE style hoses have rubber inner liners and outer sheaths, but they have steel braid inside the rubber also.
Not necessarily. High-pressure hose will indeed incorporate some fiber reinforcement, but it's often rayon, polyester, aramid (Nomex, Kevlar, etc.), or PVA (polyvinyl alcohol-derived), either alone or in combination with steel braid.
[This message has been edited by Marvin McInnis (edited 07-08-2013).]
When doing a brake job (or changing hoses) many installers make the mistake of allowing the brake hoses to over-bend or twist. If this happens it will severely weaken the brake hose and service life. Just be cautious when installing the SS hoses and they should last a long time. I use the Russell SS braided DOT approved hoses and installed 5 sets with no failures to date.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Originally posted by Many: I use X brand DOT SS Hose.
DOT test is done by the Maker or lab they paid for. Not NHTSA or others .gov. (Covered is same post...)
FMVSS Tests are done on hose provided, meaning DOT rated is only applies to lines as sold by X brand. You put a bracket to support it? That config wasn't tested by X brand and may voids any warranty etc. If/when the bracket rubs a hole etc... You could have same problem as make your own hoses.
Many SS use Clear jacket cover to meet FMVSS rules. Many SS owners report problem w/ cover turning color, cracking, etc. in 1-3 years. Maybe they use Open design rims that let more UV light get at the lines. Once cover is cracked/done then dirt etc can attack the inner liner. Teflon is mostly chemical inert but easy fail for abrasion. Dirt salt etc can get thru the SS when wet [edit and then] dry out and become micro saws. Any cracking then throw it away fast.
OE lines are tested with all parts... Support bracket, etc, included. UV light does attack "Rubber" lines but Allot slower.
I used OE rubber to restore my brakes.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
When doing a brake job (or changing hoses) many installers make the mistake of allowing the brake hoses to over-bend or twist. If this happens it will severely weaken the brake hose and service life. Just be cautious when installing the SS hoses and they should last a long time. I use the Russell SS braided DOT approved hoses and installed 5 sets with no failures to date.
Same idea... Kevlar's stronger than steel pound for pound; I don't think there's any pedal feel improvement from SS braided lines.
One thing to note about "DOT compliant" labelling on a product, is that it may or may not mean it is road legal. There are many different DOT regulations, and while something may be "DOT compliant," it may only be legal for off-road use, such as tinted license plate covers you see at AutoZone/PepBoys/etc…
Just because it's DOT compliant, doesn't mean it's meant for road use. The statement means the product meets some of the requirements set by DOT for that type of product, but it doesn't mean that all possible requirements are met for it to be legal for road use.
Here is the DOT regulation which the Russell hoses are stated to be in compliance with. You can read the test procedures outlined in S5.3 to see how the hoses are tested. You'll note that hydraulic brake hose does not have any radius testing requirements, as air brake hose does. And as noted in this thread, and the other thread that was referenced, exceeding the minimum radius requirements of the hose, seems to be the primary cause of failure. Abrasion is very rarely a cause of failure, and if it is a problem, it will likely cause a failure no matter if you're using OEM or SS hoses.
Same idea... Kevlar's stronger than steel pound for pound; I don't think there's any pedal feel improvement from SS braided lines.
I just installed SS lines and there is 100% a change in pedal feel. The pedal stops now, like it has hit a mechanical limit. It does not have the stiff spongy region at full brakes that every car I have ever driven has. I cannot get to max brakes and push them even a millimeter more.The teflon itself is stiffer than the rubber hose reinforced by fibers. When you are at the braking limit, it is easier to feel what is going on. I doubt there is a difference in feel during regular driving. Also the russell hoses are advertised on russell's site as 50 state road legal.
I think the general rule is to keep an eye on them and you will be ok.
I just installed SS lines and there is 100% a change in pedal feel. The pedal stops now, like it has hit a mechanical limit. It does not have the stiff spongy region at full brakes that every car I have ever driven has. I cannot get to max brakes and push them even a millimeter more.The teflon itself is stiffer than the rubber hose reinforced by fibers. When you are at the braking limit, it is easier to feel what is going on. I doubt there is a difference in feel during regular driving. Also the russell hoses are advertised on russell's site as 50 state road legal.
I think the general rule is to keep an eye on them and you will be ok.
Good point. Almost anything will provide better pedal feel than 25+ year old rubber hoses.
That said, in my limited experience PTFE/stainless brake hoses generally provide a "stiffer" and more linear pedal feel and are easier to modulate precisely than rubber hoses.
[This message has been edited by Marvin McInnis (edited 07-11-2013).]
Originally posted by Will: Then your OE hoses were worn out...
Had major problem... Could had air etc in the system too.
SS vs New or good Old OE, No difference in brake performance. 106 tests make sure of that.
And "swelling shut" OE hoses mostly means:
Bracket etc have rusted and pinch off flow.
Oil contamination got thru the jacket via cracks etc and swell close liner closed off flow. Brake Rubber Hates oil. Road oil on old, especially cracked, hoses WD40 etc on even new hoses can cause problem in near future. Wash w/ dish soap the oil fast when you hit them can help IF hose has No cracks. CV Grease when outer boot is bad? Not sure... Not everything hates plastic and brake rubber or much less aggressive.
My old hoses were fine (few years old) and my brakes were bled recently (like within the month) I know it does not increase performance because hoses don't affect the pressure in the line, but I like how they feel better because they feel different than rubber hoses. After driving my car for a bit the pads and everything have seated and I have a more normal amount of pedal travel, but near the limit where the brakes lock up it is easier to control in my opinion. Every car I have ever driven with rubber hoses always feels like the brakes can be pushed further once you are pushing on them as hard as you can if only you could push harder.
I don't understand why this topic is argued a million times.
SS hoses don't expand like rubber hoses do. So obviously the braking feels differently at the point where a rubber line would start to expand where a teflon line won't. Same line pressure is achieved however so there is no difference in braking performance. This also means that during daily driving nobody is going to be able to tell the difference because you will never brake that hard.
They are however more prone to failure and cannot be bent or kinked or be in contact with anything they could rub on. They should also be checked often and kept clean. You run the risk of a hidden failure no matter what if dirt or sand or salt gets into the braid and saws away at the teflon.
People have had success with them, and there have also been failures.
Originally posted by zkhennings: This also means that during daily driving nobody is going to be able to tell the difference because you will never brake that hard.
Maybe it will surprise you just how horrible some people are at "driving" on the roads. Just last night, an idiot on a motorcycle made an almost 90 degree turn into a KFC from the far left lane, cutting off 2 lanes of traffic, immediately after turning left, from a 2-lane left turn light, right in front of me. This kind of crap happens all the time. People don't pay attention to other people on the road, where they're going, or what they're doing. I can't even count the number of times people will be slowing down for a red light, and just suddenly brake hard. I've even had a lady try to get me to hit the back of her SUV once, at a right-turn yield merger.
I should get a dash cam just to record this insanity.
Rubber hoses don't expand. They have non-elastic braided material, be it steel or kevlar, in the rubber.
The phenomenon you describe sounds more like maxing out the brake booster. FieroGuru has done some tests of pedal load vs. line pressure and found that at a max effort stop, line pressure levels out even as pedal load goes up. This is a function of the booster providing the max boost force it can provide.
[This message has been edited by Will (edited 07-11-2013).]
Here is a white paper on the science. Rubber hoses expand. I understand they have a strengthening weave but they still expand as the entire line assembly is more compliant than the teflon and braided sheath.
On another note, would there be any issues with coating my lines in plasti dip or other flexible coating since they have no coating on them already? I'm mainly thinking about heat issues in my head as brake fluid can get hot.
Originally posted by zkhennings: White Paper On another note, would there be any issues with coating my lines in plasti dip or other flexible coating since they have no coating on them already? I'm mainly thinking about heat issues in my head as brake fluid can get hot.
In a "White Paper" to sell you whatever? Most White Paper = TV Infomercial. WP for cars often mix enough valid point with vague or race only data to completely bogus info. I've read that and others. Reduced expansion benefit? Street or racing w/ normal cars, Most stopping is done at low line pressure 200-900PSI. 88 Fiero gets 1500(OE)-1700(Big booster)PSI on 106.2 # foot pressure. (See https://www.fiero.nl/forum/F...2/HTML/121747-2.html ) 84-87 maybe a bit more or less. 1500-1700psi is panic stop in most cars. 100 # foot pressure on the brake pedal is hard for most people. Carmakers purposely eliminate most of your leg muscles/force on the brake pedal. (You're not in a partial or full squat.) The pedal force mostly comes from your ankle.
New OE Type hoses (Should) meets SAE J1401 and that 1/8in hose uses 1/2 or less (@ 1000PSI is 0.13 cc/ft) than FMVSS106 Low Expansion Hose. (See table in S5.3.2 Expansion and burst strength @ 106 link above.) Goodyear make a Super Low Expansion @ 1000 psi 0.06 cc/ft Old (Factory) hose? After checking, even when New, OE hoses you might see SS advantage...
SS Spec's look good on paper but they still get problem too. I won't use them to replace OE because my post above... Needed brackets, some products that crack cover in 1-3 years, etc.
Two big problem are: Too many companies make SS hoses and none of them makes OE type replacements. A set that fits Fiero can fit Many others and comes w/ universal banjos, no support brackets, etc. Good Warranty? Maybe but read the fine print. Many ways to void that. Adding a bracket can be one... This assume you lived thru a failure.
Many owners install SS hoses whatever they think will work... Often w/ bad results. 50 Fiero w/ SS lines likely has 50 ways to install them. If/when there is a problem then you often have no clue what is wrong. Bracket rub a hole can be a symptom or a root cause. Knowing which could save your etc life But most just reinstall w/ more guessing.
OE type are made to go one way w/o any guessing and newer J1401 hose are much better than factory hoses. (Hoses are labels w/ that.) J1401 has 5 layers... typical example: @ www.strongflex.com
Adding an overcoat yourself is a bad idea. Brake Fluid can eat paint, many plastic, etc... Heat? Heat could be an issue. Could cause Wicking. Can hide any problem.
(Edit to PIP the image. Old came from strongflex page)
[This message has been edited by theogre (edited 10-03-2023).]
For all the discussion about what can go wrong with stainless steel hoses, it still seems there are more causes for concern using rubber hoses.
Unless I'm missing something, the problems with both types of hoses are:
a. accidentally bending them under the minimum radius;
b. the possibility of having non-Fiero specific hose ends; and
c. may not be DOT approved
Problem unique to stainless steel braided hoses seem to be:
a. susceptible to having the strands eventually break and eat into the Teflon inner tube;
The problems unique with rubber hoses seem to be:
a. Susceptible to oil contamination;
b. Susceptible to UV breakdown;
c. susceptible to rusted fittings pinching off the hose; and
d. susceptible to abrasion damage
It seems to me that anyone with common sense can eliminate the common problems associated with all three simply by buying a properly manufactured hose and installing it correctly. That leaves the specific problems with each hose to consider. In my opinion, there seems to be more potential issues with the rubber hoses than with the braided hoses.
Originally posted by Bloozberry: Problem unique to stainless steel braided hoses seem to be:
a. susceptible to having the strands eventually break and eat into the Teflon inner tube;
Unless you have something such as a bracket that has rusted through or is a sharp steel thing, constantly rubbing against the braided line, I doubt this will be an issue. The wire strands are quite strong, and aren't likely to break themselves under normal usage, and if properly installed. Poorly fitted ends to the hose, improper length in install, minimum bend radius being compromised, improper angles of install that would cause twisting of the line, or rubbing against another hard/sharp object, are what will cause critical failure of the stainless lines.
Use hose of the right length, which has the clear plastic/rubber sheath where the hose goes into the fittings, and installed at the right angles and bend radii, and everything should be fine. The plastic/rubber sheath is like a grommet, and helps to give some protection to the braids under flexure, where they could rub against the edge of the fitting. If you keep the lines cleaned, and watch those sheaths for wear at the edge of the fitting, you'll know when to replace (or just rebuild) the lines. If it wears through, you're probably seeing too much flex/pull on the hoses at the fittings, and it could start wearing through the steel braid as well.
Here is a white paper on the science. Rubber hoses expand. I understand they have a strengthening weave but they still expand as the entire line assembly is more compliant than the teflon and braided sheath.
On another note, would there be any issues with coating my lines in plasti dip or other flexible coating since they have no coating on them already? I'm mainly thinking about heat issues in my head as brake fluid can get hot.
LOL. That paper is garbage. It cites NO test data. NONE. If the claims that paper makes are correct, it should be very simple to develop a pressure vs. volume data set from which dramatically different coefficients of volumetric expansion can be derived showing that the braided SS is dramatically superior to the OE rubber. This isn't presented with good reason... such data doesn't exist.
quote
Stainless Steel lines provide a number of benefits as compared to their OEM rubber overmolded counterparts. 1. The SS braid provides superior protection from flying roadway debris. 2. The SS braid and Teflon hose reduce expansion during pressurization. 3. They provide the race car look.
#1 is a lie outright #3 is idiotic
#2 is false for the reasons the paper cites. Rubber hoses are JUST LIKE BRAIDED SS. BOTH have an inner liner that seals the fluid and is impervious to chemical attack by it. BOTH have a braided overwrap of a high tensile fiber. However, the OE lines have additional layers of rubber to protect the braid road hazards, grit, corrosion. The outer layer is impervious to chemical attack by oils and other engine bay chemicals which could degrade the inner layer.
For all the discussion about what can go wrong with stainless steel hoses, it still seems there are more causes for concern using rubber hoses.
Unless I'm missing something, the problems with both types of hoses are:
a. accidentally bending them under the minimum radius;
-OE style rubber lines have smaller minimum bend radius than teflon and due to greater flexibility of inner liner, are not nearly as degraded per bending event as teflon/SS. -Using stock replacement OE fit lines with appropriate brackets eliminates bend radius concerns. -Intelligent brake upgrades still use OE hoses. I'm using OE hoses and outlined my brake configuration above.
quote
Originally posted by Bloozberry: b. the possibility of having non-Fiero specific hose ends; and
c. may not be DOT approved
Neither of these are a problem with OE fit hoses.
quote
Originally posted by Bloozberry: Problem unique to stainless steel braided hoses seem to be:
a. susceptible to having the strands eventually break and eat into the Teflon inner tube;
And more significant bend radius restrictions. ONE incident of undercutting the minimum bend radius can compromise a teflon/SS hose.
quote
Originally posted by Bloozberry: The problems unique with rubber hoses seem to be:
a. Susceptible to oil contamination;
No. The OE rubber skin resists oil and engine compartment fluids.
quote
Originally posted by Bloozberry: b. Susceptible to UV breakdown;
Not really sure, but your brake hoses don't see much daylight. How long does it take a tire to dry rot? Extend that period of time significantly for a brake hose due to lower exposure.
quote
Originally posted by Bloozberry: c. susceptible to rusted fittings pinching off the hose; and
This is not a credible failure mode, in my opinion.
quote
Originally posted by Bloozberry: d. susceptible to abrasion damage
Anything is susceptible to abrasion damage. OE lines are less susceptible to it because of the exterior rubber layer protecting the braid.
quote
Originally posted by Bloozberry: It seems to me that anyone with common sense can eliminate the common problems associated with all three simply by buying a properly manufactured hose and installing it correctly.
Bingo.
quote
Originally posted by Bloozberry: That leaves the specific problems with each hose to consider. In my opinion, there seems to be more potential issues with the rubber hoses than with the braided hoses.
What I meant was that when measured simply against the pros and cons discussed in this thread up to my last post, there seem to be more reasons not to use rubber lines than stainless braided ones.
My rubber hoses rubbed against my new tires for all of two minutes and it took off ALL the rubber down to the inner braid. That would not happen with SS hoses. I can snap a picture if you don't believe me. I drove all of 1 mile to make sure the new wheels and tires weren't rubbing anything, and I was hearing a rubbing sound so I drove straight home and when I got home, the line was against the wheel and it destroyed the outer rubber.
Will - Rubber hoses expand more! It is a fact, they have a rubber inner before the braid, that rubber can compress, and the braid doesn't stop as much expansion as the SS sheath and pretty much incompressible teflon line. Here is actual test data showing rubber line expansion vs SS. Now of course this is not a ton of difference, but it results in a noticeable difference in pedal feel. And this is just exterior expansion, the interior diameter can expand more than the exterior because the rubber within the braid can compress too. And they tested brand new rubber hoses! Where have you ever read or seen that the rubber lines expand as much as the SS lines?
[This message has been edited by zkhennings (edited 07-12-2013).]
Originally posted by zkhennings: My rubber hoses rubbed against my new tires for all of two minutes and it took off ALL the rubber down to the inner braid. That would not happen with SS hoses.
Right, they'd take the rubber straight off the tire instead.
My rubber hoses rubbed against my new tires for all of two minutes and it took off ALL the rubber down to the inner braid. That would not happen with SS hoses. I can snap a picture if you don't believe me. I drove all of 1 mile to make sure the new wheels and tires weren't rubbing anything, and I was hearing a rubbing sound so I drove straight home and when I got home, the line was against the wheel and it destroyed the outer rubber.
Even with the outer layer of rubber worn through, the OE style hose was still safer than the SS/Teflon hose, as the OE hose still had two layers of braid to wear through.
I'm not sure that's even relevant, as constant wear against a tire isn't part of the design environment for either technology. There was obviously a serious problem with component locations if it was held against the tire that forcefully.
quote
Originally posted by zkhennings: Will - Rubber hoses expand more! It is a fact, they have a rubber inner before the braid, that rubber can compress, and the braid doesn't stop as much expansion as the SS sheath and pretty much incompressible teflon line. Here is actual test data showing rubber line expansion vs SS. Now of course this is not a ton of difference, but it results in a noticeable difference in pedal feel. And this is just exterior expansion, the interior diameter can expand more than the exterior because the rubber within the braid can compress too. And they tested brand new rubber hoses! Where have you ever read or seen that the rubber lines expand as much as the SS lines?
At least you're figuring out how to post test data now.
Don't forget this quote:
quote
the margin is extremely small
However, reading on I find some meaningful numbers:
quote
When testing volumetric expansion, Goodridge found that standard OE-type rubber brake hose expanded by 0.136 cc/ft at 1,000 psi, 0.150 cc/ft at 1,500 psi, and 0.290 cc/ft at 2,900 psi, whereas the company's PTFE braided stainless hoses expanded by only 0.0002932 cc/ft at 4,000 psi.
Can you realistically feel half a cc difference in brake line volume--spread across all four hoses--in a max effort stop? No. I would expect the stock Fiero aluminum calipers flex a lot more than that.
Edit: I had the stock Fiero clutch line, which is teflon/SS, wear through and spring a leak. It was from nothing more than prolonged contact with the transmission case... which is aluminum. Really, .020" (or whatever) SS wire is not very tough. As steels go, stainless has a fairly low yield strength.
[This message has been edited by Will (edited 07-12-2013).]
As stated there is internal compression as well so that outer diameter change is not the full amount of volume change of the hose. You can feel a difference, why do many racecars use SS hoses if there is no change in the way the car brakes/feels? I understand it is not like magic, it is not like the difference is night and day, but it is easy to tell that there is a difference.
Problem unique to stainless steel braided hoses seem to be:
a. susceptible to having the strands eventually break and eat into the Teflon inner tube;
You might add the susceptibility of the PTFE (Teflon) inner liner to collapse/crimp failure when bent too sharply. PTFE tubing behaves much like semi-rigid metal tubing in this regard. In contrast, most commercial rubbers are highly flexible throughout the range of normal ambient operating temperatures. Yes, rubber hose will also collapse when bent sharply, but will seldom crimp permanently, and it will normally recover its original shape and strength when allowed to relax.
quote
Originally posted by zkhennings:
... why do many racecars use SS hoses if there is no change in the way the car brakes/feels?
One reason: Brakes of racing vehicles usually operate at much higher temperatures than on street vehicles. The mechanical properties of most rubber compounds degrade rapidly with increasing temperature, but PTFE (Teflon) tolerates high temperatures well. In fact, Teflon was first developed during WW-II for the Manhattan Project, for use in thermal and/or chemical environments where rubber hoses and seals could not survive ... e.g. handling hot uranium hexafluoride.
Second, competitive race cars live in an environment where differences on the order of tenths of a percent can mean the difference between winning and losing. Most such differences are likely to be both imperceptible and insignificant in a street-driven vehicle.
In addition, serious race cars are subject to careful inspection before and after each race ... both by their own crews and by the sanctioning body's scrutineers. Any brake hose showing evidence of wear or damage is immediately replaced. Street vehicles often go years between brake hose inspections or replacements.
[This message has been edited by Marvin McInnis (edited 07-13-2013).]
For all the discussion about what can go wrong with stainless steel hoses, it still seems there are more causes for concern using rubber hoses. No...
Unless I'm missing something, Yes and some are in wrong categories. A few highlights...
Problem unique to stainless steel braided hoses seem to be: a. accidentally bending them under the minimum radius. Very easy when use as drop-in replacement for Factory hoses. b. the possibility of having non-Fiero/OE specific hose ends.
Most OE replacement come w/ correct ends. Some/Many SS uses correct end on body/frame connection but use a Universal banjo on caliper.
The shape on OE caliper end acts like a lock washer... Square end hits the shoulder on the caliper. (Most cars use this feature or similar to it.)
SS w/ universal banjo can work/vibrate loose over time or even pulling hose can loosen the banjo, Especially used in Al calipers and low Torque spec on banjo bolts. c. may not be DOT approved
You live in Canada so may or may not matter.
Hard to impossible to find OE "Rubber" hose assemblies w/o DOT compliant.
[Edit]Again, DOT/NHTSA doesn't approve anything.
The problems unique with rubber hoses seem to be: a. Susceptible to oil/chemical contamination causing liner to swell; old/factory? yes. New/good Old hose could "wick" contamination thru pours in jacket... b.Most Old rubber does Expand more even when new. J1401 hose have much less Expansion then Factory and more resistance to oil/chemical/etc attacks. --------- All, J1401 hose is a "new" item. [Edit ->] SAE Published the standard in 1999 and updated since. Most Products show up ~2005 and up. Likely You can find parts w/o J1401 hose but don't buy them. (Raybestos PG Plus and others use J1401 hose.) Google: sae j1401
"Goodridge Report," Mentioned in the WP above, here http://www.gotyournose.com/...ainless_v_rubber.pdf Goodridge makes SS hoses... IE another WP trying to make case against J1401 to help their own sales numbers. Burst/Working Pressure Conclusion? Again, Most Street cars use ~1800PSI max, normal Working pressure 200-900PSI... Whip Test Conclusion? Sample size 5 hoses for OE and means nothing. Hose Life Expectancy? Complete
quote
Rubber Hose - 3 years or 60,000 miles Note - This is the average quoted life expectancy, We have not carried out any testing to verify this data.
[This message has been edited by theogre (edited 04-16-2019).]
As stated there is internal compression as well so that outer diameter change is not the full amount of volume change of the hose. You can feel a difference, why do many racecars use SS hoses if there is no change in the way the car brakes/feels? I understand it is not like magic, it is not like the difference is night and day, but it is easy to tell that there is a difference.
quote
Originally posted by Marvin McInnis:
One reason: Brakes of racing vehicles usually operate at much higher temperatures than on street vehicles. The mechanical properties of most rubber compounds degrade rapidly with increasing temperature, but PTFE (Teflon) tolerates high temperatures well. In fact, Teflon was first developed during WW-II for the Manhattan Project, for use in thermal and/or chemical environments where rubber hoses and seals could not survive ... e.g. handling hot uranium hexafluoride.
Second, competitive race cars live in an environment where differences on the order of tenths of a percent can mean the difference between winning and losing. Most such differences are likely to be both imperceptible and insignificant in a street-driven vehicle.
In addition, serious race cars are subject to careful inspection before and after each race ... both by their own crews and by the sanctioning body's scrutineers. Any brake hose showing evidence of wear or damage is immediately replaced. Street vehicles often go years between brake hose inspections or replacements.
All of the above AND: Most pro-level race cars use non-standard calipers, rotor diameters, and may change out every other component in the brake system. In the cases of many dirt trackers, the entire car is whipped up from things the racer/team had lying around or found in a junkyard.
THERE ARE NO OE style hoses made for these non-standard configurations.
In other words, racers have no choice but to use custom braided stainless lines.
[This message has been edited by Will (edited 07-29-2019).]
.jpg)
.jpg)
@ 
