Posted: March 12 2005 at 11:19am | IP Logged

What is the value of having stainless steel lines.

I know they are stiffer and make them feel better.

Posted: March 12 2005 at 2:57pm | IP Logged

Stainless lines are a very minor improvement, and one you may not even notice, in reality. The idea is that the rubber lines that come stock on most all cars expand due to the pressure within the braking system, and therefore there is a very slight delay to reach a given braking pressure (measured at the calipers) compared to stainless lines. The reality is the expansion is extremely minor, so you probably wouldn't notice the difference.

The disadvantage is that stainless lines are teflon inside, which is very fragile. The stainless braid is there in part to protect the teflon, but the reality is the stainless braid doesn't take concussive or pinching abuse as well as stock rubber lines - so stainless lines are easier to damage. If the line gets pinched in your suspension movement or gets hit with a flying stone in say a two-wheel off situation, it can hole the line and you can completely lose your braking ability. I've been there and it's exciting to say the least.

So that's pretty much it. There are pros and cons to both.

Posted: March 23 2005 at 9:50am | IP Logged

 John,

 As far as what I have seen the only teflon on stainless steel brake lines is on the outside, to prevent the steel braid from sawing into components that the line may rub against as the suspension travels up and down. The brake lines and the clutch line I have on my car, as well as all the stainless steel hydraulic lines I've worked with on hydraulic presses and machinery, were all constructed in the same manner; a rubber hose with a stainless steel sleeve over it, and either a PVC or a teflon coat over the SS sleeve. The rubber line on the inside is roughly the same inner diameter as the stock rubber lines on the car, but the outer diameter is indeed smaller since a steel mesh goes over it. Nonetheless, all the DOT approved ones have to pass a hydrostatic test @3500PSI and I have seen some tested at 5000PSI.
 I'm not saying that all brake lines are made like that, but given that the force on the walls of a cylinder goes up with the square of the radius, if you made a line with nothing but the steel braid and a thin inner tube made of Teflon, the inner diameter would be very large, the forces on its walls would be enourmous, and I would not be surprized to see it burst.

 As far as weather it is noticeable or not... I did brake lines, pads and rotors all at once, and I did notice a huge difference, but I couldn't say for sure that it was just because of the lines.

Posted: March 27 2005 at 3:18pm | IP Logged

I've never seen stainless brake lines with rubber inside them. Goodridge, the largest manufacturer of stainless brake lines says this:

GOODRIDGE BRAKELINE KITS

Goodridge stainless steel brake hose kits are available to suit most models of car or bike, whatever the make. Kits feature the finest quality hose, consisting of a PTFE inner with a stainless steel outerbraid. This eliminates the spongy pedal feel under arduous conditions, giving greater braking efficiency or clutch operation, as well as providing superior resistance to abrasion and corrosion. These kits, therefore, not only provide the reliability and safety demanded, but offer brilliant good looks that improve the appearance of any installation. Most brake kit specifications are on file but any additional information is always appreciated."

PTFE =  PolyTetraFluoroEthylene, a fluorocarbon-based polymer. The Teflon brand of PTFE is manufactured by DuPont.