Brake Lines and Hoses
Automotive braking systems use double-walled steel tubing as their standard OEM brake line. Brake lines and flexible brake hoses transmit fluid pressure from the master cylinder to the wheel braking units. The line consists of two steel tubes welded together at the seams and coated with tin or alloy to prevent corrosion. The ends are flared to match its companion seat. The flares will be either ISO or double.
It's always best to replace a rusted or damaged line with a preformed line designed for the vehicle. Never use compression fittings on brake lines. There are tools available to bend the lines and create the flared fittings when originals are not available. Brake lines fasten to the chassis or frame with fasteners to reduce vibration and a horseshoe clip where it meets the flexible hose.
Brake hoses are used between the wheels, axles, and the frame. They allow for movement as the front wheels pivot, or the rear axle moves over bumps in the road. These hoses can become brittle and cracked in time, causing them to leak.