Bret 944

Correct me if I'm wrong, but all 944's came with rubber brake lines, correct? When doing my rear brakes on my '88 last weekend, I noticed that my rear lines were metal, I guess steel. It kind of made it harder to change the pads, because steel doesn't quite have the flexibility of rubber, but it's a nice upgrade otherwise. Nice to know one of the PO's upgraded something.

Bret

ELLSSUU

On the rear there are hard lines going into the caliper which lead to the soft lines mounted much further in the car. Ofcourse, someone could have changed your softlines with metal braided lines but they're still flexible. If you're talking about the thin lines to the calipers then you're probably looking at the wrong ones.

Bryans951

actually if you follow the line up a little while it turns to rubber for about 10inches then goes back to steel.

IceShark

Yes, Porsche apparently wanted steel hard lines for a little ways to act as a heat sink and shed hard braking heat better.

Ag951

Having steel everywhere but the flex part also keeps the brake from fading as much when it gets warm. Those solid steel lines won't expand like rubber will.
My SS brakelines are more flexible than the 17 year old rubber that was on there.
If you compete in your car, the SS brakelines are a very good mod idea.

Sam Lin

What's the difference between the DOT-legal SS lines and the non-DOT-legal, except $10-15? I haven't found an answer anywhere, it's really bugging me (not that it matters, I ordered a DOT set).

Thanks!
Sam

Ag951

DOT legal means its legal on US roads.

led

But is there any material difference between DOT and non-DOT?

Sam Lin

Sorry for being unclear, led's question is what I was asking also - any physical build differences?

Sam

jason952

and I have heard that smart folks replace SS lines at a certain interval, what should I use?

Jason

W88951

I am not certain if there is any material difference between DOT leagal and not DOT legal brake SS brake lines. Probably the biggest difference are the costs involved in certifing the lines. I know that the SS brake lines on my RX-7 are not DOT approved, but when I bought them 7 years ago, nobody made DOT approved SS lines.

As far as the solid lines go in the original post, those are factory. The rubber lines are further under the rear suspenion where it actually moves. Replacing them is probably a good idea, but not necessary unless you know the lines are bad.

led

FWIW, I've read and have been told by a friend or two that the braided lines eliminate some of the "sponginess" of the brake pedal.

IceShark

Luis, that is because the stainless braided lines, at least the good ones, have a teflon inner lining or similar stiff material that can take the fluid, heat and pressure. The stainless braid is for looks and *maybe* the odd encounter with a road debris. That is about it. No Value to speak of.

Most of these components are self (the OEM) certified anyway to DOT so being DOT certed is not exactly a proof of fitness.

Ag951

There is a huge benefit to SS brake lines!
It's not for looks, and it's not because I'm worried about debris cutting the line.
I have them because they don't expand when you put pressure on the brake pedal. When you squeeze the brake, the fluid follows the path of least resistance. The solid steel lines are obviously not going to expand under human induced pressure, so it's between the rubber lines and the pistons. Some of the pressure goes to forcing the pistons out, but some of it is absorbed by expanding the rubber lines. As the rubber heats (from lots of braking) it begins to expand even easier, making the brake spongier.

If you never drive your car on a track, SS lines are less useful. But I doubt any serious track driver or autocrosser here uses rubber lines.

Sam Lin

You'd be surprised how many racers say SS lines are a waste of money and are useless. The benefit in pedal feel usually comes from the good bleeding the brake system gets after the line swap.

Sam