HDD 151 - Heavy Duty Diesel Engines Level II

1. Complete NATEF tasks related to Cylinder Head and Valve Train as listed below.
   1. Inspect cylinder head for cracks/damage; check mating surfaces for warpage; check condition of passages; inspect core/expansion and gallery plugs; determine needed action.
   2. Disassemble head and inspect valves, guides, seats, springs, retainers, rotators, locks, and seals; determine needed action. Listen for engine noises; determine needed action.
   3. Measure valve head height relative to deck and valve face-to-seat contact; determine needed action.
   4. Inspect injector sleeves and seals; measure injector tip or nozzle protrusion; determine needed action.
   5. Inspect valve train components; determine needed action.
   6. Reassemble cylinder head.
   7. Inspect, measure, and replace/reinstall overhead camshaft; measure/adjust end play and backlash.
   8. Inspect electronic wiring harness and brackets for wear, bending, cracks, and looseness; determine needed action.
   9. Adjust valve bridges (crossheads); adjust valve clearances and injector settings.
2. Complete NATEF tasks related to Engine Block as listed below.
   1. Perform crankcase pressure test; determine needed action.
   2. Install and align flywheel housing; inspect flywheel housing(s) to transmission housing/engine mating surface(s) and measure flywheel housing face and bore runout; determine needed action.
3. Complete NATEF tasks related to Cooling System as listed below.
   1. Test coolant temperature and check operation of temperature and level sensors, gauge, and/or sending unit; determine needed action.
   2. Inspect and reinstall/replace pulleys, tensioners and drive belts; adjust drive belts and check alignment.
   3. Inspect thermostat(s), by-passes, housing(s), and seals; replace as needed.
   4. Recover coolant, flush, and refill with recommended coolant/additive package; bleed cooling system.
   5. Inspect water pump and hoses; replace as needed.
4. Complete NATEF tasks related to Air Induction and Exhaust Systems as listed below.
   1. Perform air intake system restriction and leakage tests; determine needed action.
   2. Perform intake manifold pressure (boost) test; determine needed action.
   3. Check exhaust back pressure; determine needed action.
   4. Inspect turbocharger(s), wastegate, and piping systems; determine needed action.
   5. Inspect turbocharger(s) (variable ratio/geometry VGT), pneumatic, hydraulic, electronic controls, and actuators.
   6. Check air induction system: piping, hoses, clamps, and mounting; service or replace air filter as needed.
   7. Inspect, clean, and test charge air cooler assemblies; replace as needed.
   8. Inspect exhaust manifold, piping, mufflers, and mounting hardware; repair or replace as needed.
5. Complete NATEF tasks related to Engine Brakes as listed below.
   1. Inspect and adjust engine compression/exhaust brakes; determine needed action.
   2. Inspect, test, and adjust engine compression/exhaust brake control circuits, switches, and solenoids; determine needed action.
   3. Inspect engine compression/exhaust brake housing, valves, seals, lines, and fittings; determine needed action.