Left front rubber line from frame to caliper came apart. 2000 Lincoln Navigator 4wd. The part on the caliper. Had about a three inch long metal line with double flare on the end coming out of the rubber part connected to the caliper. The other part connected to the frame had a sleeve on the end of the rubber line connected to the frame. Came apart coming up to stopped traffic on a bridge. Car came to rest between car in front of me and the guard rail. No damage to anything. I thought the read brakes should have stopped better. They slowed the car down to a coasting stop. I shoved the metal part back into the rubber sleeve and I cannot pull it apart. The only way that failure of the line coming apart is if the compression holding the two parts together was not sufficient .