OTTO Excavator Parts Tfr17 4Ze1 Cooling Water Bypass Pipe 8944740780 894474-0780 8-94474078-0 For Isuzu Durable 8-94474078-0 pipe fits OTTO Tfr17 & Isuzu 4Ze1. Resists mining dust/heat, pressure-stable. Ensures steady engine cooling for non-stop heavy work.