1990 Pontiac 6000 What is the long rear rubber brake line c

I have a 1990 Pontiac 6000 LE (4 cylinder). A few days ago I took my son to school and the brake pedal went to the floor. I got out and found a leak in a long rubber brake line near the rear driver side tire (under the frame, not in the wheelwell). My question is, does anyone know what the part is called? I have been to a few auto parts stores and no one has the same part or knows what it is. The line appears to originate in the block and travels back and over to the passenger side rear tire first. Not sure if it is entirely rubber or rubber coated steel line. Thanks, Paul