TM10-3930-660-34 g.   High Pressure Fuel Lines.  The high pressure fuel lines are designed and manufactured to deliver fuel at injection pressure to the injectors.  The high pressure pulses will cause the lines to expand and contract during the injection cycle.  The high pressure fuel lines are clamped and routed so that they do not contact each other or any other components. h.   Fuel Drain Manifold.  The fuel system is designed to use fuel to cool and lubricate the injection pump and injectors. Fuel is continually vented from the injection pump and a small amount of fuel leaks by the injector needle valve stem during injection.  This fuel is returned to the supply tank by the fuel drain manifold. Section II.  FUEL SYSTEM MAINTENANCE PROCEDURES. FUEL SYSTEM MAINTENANCE TASK SUMMARY TASK PAGE PARA. PROCEDURES NO. 4-3 Fuel Injector - Test/Replace 4-5 4-4 Fuel Injection Pump - Replace 4-9 4-5 Fuel Shutoff Valve - Replace 4-14 4-6 Turbocharger Assembly - Repair 4-16 4-7 Fuel/Hydraulic Tank - Replace/Repair 4-24 4-4