The most common brake lines on a Chevy Malibu are
double-walled steel lines. While the exact diameter and routing might vary slightly depending on the model year and specific trim level, steel brake lines are the standard across nearly all Malibu generations.
You won't typically find rubber or other materials for the main braking system lines. Rubber hoses are used for flexible connections near the wheels (the brake hoses), but the rigid lines running through the chassis are almost always steel.
