What Are “DOT-approved” SS Lines?
[AWN] A few people have asked me to explain the difference between “DOT-approved” and non-approved stainless-steel brake lines. This explanation is pretty long, but I think it’ll explain everything so I won’t ever have to post another message on the subject… I’ll just refer anyone who asks to the Porschelist searchable archives. First, a quick explanation of what stainless-steel brake lines ARE: The brake lines we’re talking about are the flexible ones that connect between the hard lines (i.e., the inflexible tubing) in the car and the brake calipers on the wheels. They’ve traditionally been made from rubber tubing, with steel or aluminum connectors crimped onto their ends. Nearly all passenger cars are shipped with rubber brake lines, and they hardly ever fail. “Stainless-steel” lines are made of Teflon tubing, not rubber. Teflon has a number of advantages over rubber; the chief ones are that it doesn’t expand under pressure and it doesn’t deteriorate with age. It also resists high
