We replaced all four hoses, front and rear and that corrected the problem. Although the brake pedal is not as high as the mechanic wanted it, the brakes do respond and the brake pedal no longer drops to the floor. My mechanic did not replace these hoses earlier becasue he beleived that if the hoses were expanding then he would be able to see the expansion. However, a long term Honda mechanic suggested to him that since the hoses are double lined that it was probable that the interior lining of the hose that was wearing away and causing the expansion. Thnaks for the tip. It put us back on track.