the "heater hose" # 64 21 1 370 807. After the recall this is split by the pressure deverter, part # (hold on I need to fire up the ETK) Drat I can not find the part number. Just cut it in two, to match the old ones. Also, the part added due to the recall, the pressure deverter, needs a line, around 2 1/2' long and two clamps. I recall it is the same size as the thin expantion tank hose. When I did mine, my pressure deverter was badly coroded on the two flanges that took the heater hose. Have a spare if your's is original. Mine needed replacing.