Thoughts on stainless steel brake lines

[moribundman]

What are your thoughts on the reliability of stainless steel lines (vinyl-coated) and the ability to gauge when they need to be replaced.

Cost:

- set of ss brake lines for front: $59
- set of OEM rubber brake lines for front: $20

Rubber lines appear to last about 9 years in my climate. Surely ss lines will last longer since the internal (rubber?) hose is not exposed to the elements, but how to check the ss lines for internal deterioration?

 

[Kestas]

I don't believe any brake line - plain steel or stainless steel - suffers from any horrible corrosion from the inside. Internal corrosion is usually limited to where the seals are located (calipers, wheel cylinders, and master cylinder) because of water diffusion past the seal.

Come to think of it, I'm not sure I understand your question. What do you mean by "ss lines will last longer since the internal (rubber?) hose is not exposed to the elements"?

 

[moribundman]

Well, my 9 year old OEM rubber (no metal apart from screw connectors) brake lines show some hairline cracks where the brake lines bend. It's time to replace them. If I go with OEM rubber brake lines, any future deterioration will show. I'm inclined to get stainless steel lines, because they make for improved pedal feel, but my concern is that I can't see the condition of the brake hose under the stainless steel wrapping. I assume it's a rubber hose with teflon liner.

When I mentioned exposure to the elements, I was referring to the rubber brake line being shielded by the stainless steel braiding and the vinyl coating. Let me compare it to vacuum tubing. OEM Audi vacuum tubing has a cloth cover, which makes it impossible to notice small tears and cracks in the tubing.

 

[bheinz57]

I believe SS lines are worth the extra penny. They will provide less flex of the brake fluid when braking, providing a frimer pedal somewhat. And they allegedly do last a bit longer than rubber only hoses.

The regular old rubber lines are subject to wear from the outside in a lot easier than the SS vinly coated versions.

If you can afford the extra buck, SS lines are worth it in my opinion.

Brian

 

[Kestas]

Okay, I misunderstood. I thought you were talking about ss tubing for brake lines.

I think you've correctly assessed the pros and cons of using ss braided rubber brake lines.

It's up to you whether the improved brake pedal response is worth the lack of inspection for deterioration and cost.

 

[moribundman]

Well, let's say the ss lines will last at least as long as the rubber lines. That would be at least nine years. The car will be 18 years old then. Hmm...

 

[labman]

I would imagine a big factor in the life of the SS braid over Teflon would be the care removing calipers. Drop them too many times and you could kink the hoses. Otherwise, ?????????

 

[moribundman]

Yeah, dropping a 4 pound caliper would probably break or at least damage any brake hose. That's why I suspend the caliper with a thick wire from one of the upper control arms.

 

[Big Jim]

As long as you don't kink them, stainless steel brake lines seem to hold up indefinitely. They do swell less under pressure so brake pedal feel is improved.

Most stainless steel lines are not DOT approved. To be DOT approved, the ends must not be removable. Most stainless steel lines do have ends that can be removed and replaced without replacing the entire line. You will need to decide if that is an issue for you or not.

Stainless steel lines tend to be abrasive and can wear on parts that they rub against, such as struts or other suspension parts. Since they usually have a smaller outside diameter, they may not fit the factory retainers very well, so make sure that something is done to hold them in place, such as tie them up with nylon ties.

Personally, I don't see much need for them outside of racing applications. I can't remember the last time I had to replace a rubber brake hose on a car I've owned, and I keep my cars for a long time. When it is time to replace them, I might think about it though.

Most of the ones I've seen for sale run around $100.00 a pair or a little more.

 

[Pablo]

Mine have lasted stinking forever on my Volvo. I abuse my....er car.....regularly.

 

[Master ACiD]

ok, here be the low down on stainless lines versus normal rubber lines.

stainless lines, which you should only consider if they are dot approved, can get dirt trapped between the braids, which rubs away at the actual line underneath the braid. for this reason you will want vinyl coated lines that are dirt proof. if they are not, you could probably heat shrink them, i dont know for sure as i never tried. just thought of that one actually.

i have stainless on my car and the improvement of stainless brand lines versus new rubber lines is incredible. the petal feels much more firm, almost as if the rubber lines had some air in them which i couldnt get out.

stainless is worth it in my book, but dont kid youreself if you think stainless is going to make you stop quicker. stopping distance, as far as brake lines are concerned, is a function of pressure. if rubber lines can give enough pressure to skid a tyre without the line rupturing, than they are certainly "good enough" for youre current setup.
upgrading to stainless lines wont make you stop quicker. although some argue that stainless braid lines give you far more control over petal modulation so that you can maintain the brakes at the peak threshold where the tyres are constantly on the verge of locking up.

i dont know how ans would factor into the threshold, but if youre stockers are cracking, its time to replace them anyways, might as well go for stainless braid if you have to do the job anyways.

 

[moribundman]

Yes, the ss lines I have in mind are DOT approved and vinyl-coated. Yes, I know the stopping distance won't be shorter and it's about pedal feel. I think I mentioned that.

And no, on my car the ss lines won't rub. They are custom-made to fit the vehicle perfectly.

ss brake lines

 

[jaj]

mori

I've got a car that sees some track time every year in the summer, and for that I use a "big brake kit" and stainless lines. In the winter I switch the whole setup back to the stock factory rubber lines and OEM calipers and rotors.

The way I see it, the factory put tons of time and energy into making sure the OEM parts will perform under any situation and weather condition they could possibly see, and do so for years, even decades. The high performance parts give a boost in performance, but since nothing comes for free, there must be a trade-off, and since I don't know what it is, I go for the low risk alternative.

SS brake lines are adapted from racing, and they do improve pedal feel and control. The manufacturers recommend they be inspected regularly for damage or wear. Even if they fit perfectly, they can still rub on something and develop a weak spot. One of the other M5 crowd lost his brakes at 130MPH at the end of a long straight when a stainless line burst at a worn spot. This technology comes with a risk.

If you want to install new brake lines and forget about them, then put new OEM lines in. If you can inspect them at least once a year, without fail, then stainless is ok. But they're not OEM replacements - they are specialized items and they aren't for everyone.

By the way - DOT doesn't approve brake lines. They prescribe manufacturing processes and test procedures but they don't test anything or approve anything - the component manufacturers certify that their product meet DOT specs. Since there is no watchdog or oversight, you're taking their claims entirely on trust!

The brakes and lines I use are made by Stoptech in California. They make Audi brake kits and SS lines, and the lines are certified to DOT specs, and 100% tested at 4500PSI. It's good stuff.

Cheers
JJ

 

[OdinsRage]

the brake lines in my 04 VW golf look plain rubber but apparently the inside is kevlar re-inforced or something, pretty expensive and almost indestructible

 

[moribundman]

jaj, DOT approval is via self-certfication? Yikes.

The SS lines I have in mind are from ECS. They "should" be of good quality.

I spend at least an hour under my car once a month. I generally do notice wear and tear of components way in advance before there are any issues.


OdinsRage, I'll cut my old brake line and let you know if there's an internal kevlar, teflon or nylon liner.

 

[crew219]

mori . . . . ECS lines are merely "precise" lines. ECS just sells them and slaps their name on them. That being said, they can usually be had @ www.germanautoparts.com for a good bit cheaper than ECS.


Dave

 

[moribundman]

crew, would you say the germanauoparts/ECS lines are worth the extra $40, or would you stick with OEM lines?

 

[crew219]

Honestly, I didn't notice a difference. The OEM lines had a nylon braid on the inside and I don't think that they flexed substantially more than SS lines.

I'd go by cost of the parts. I'd probably spend the extra $40 on better brake pads or new brake bushings. I assume this is for your 12v 2.8L? These do a lot more than the SS lines IMO.

http://www.tyrolsport.com/audiperformance.htm

Dave

 

[moribundman]

Sounds like I can save myself the extra expense and just go with the OEM lines instead.

 

[unDummy]

Stainless braided 'hoses' are worth it. Just make sure you buy the DOT approved ones. If dirt is an issue where you live, then dip the hoses in tool dip or use a lenth of heat shrink tubing to "seal" the braid from the dust/dirt.

I've never changed a hose for maintenance until there was a failure(8 or so hose failures in 16 years and was able to stop each car with brake pedal each time). So, my brake hoses are never inspected. When one fails, all get replaced.
I won't worry about "inspecting braiding hoses". If there is wear after many years of use, they'll leak instead of bursting. For safety sake, you could replace the braided hose every 10 years if you keep the car that many more years.

Now that I think about it, all of my brake hose failures had OEM hoses that were about 8-9 years old when they failed.

If cost is an issue and you need to replace your hoses, replace ALL of them and don't bother choosing. I'd rather see you replace all OEM hoses with new ones instead of just replacing the fronts with braided hoses.

Reference FMVSS 106 for brake hose testing. I do not believe that it is 'independent'. I'm under the impression that the actual hose must be submitted to DOT or someplace approved by DOT for testing.