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Heavy Duty Diesel Heating, Ventilation, & Air Conditiioning

HDD 207

Heavy Duty Diesel Heating, Ventilation, & Air Conditiioning

HDD 207

Course Description

Prerequisites: Prerequisites: HDD 202 and HDD 206 both with a grade of "C" (2.

0) or better. Corequisites: HDD 203W, HDD 209W, and HDD 210. Introduces and practices the service of heavy duty diesel vehicle heating, ventilation, and air conditioning (HVAC) systems. Practices NATEF tasks related to HVAC systems of heavy duty diesel vehicle. (60-30)

Outcomes and Objectives

Complete general HVAC system diagnosis and related NATEF tasks as listed below.

Objectives:

  • Verify the need for service or repair of HVAC systems based on unusual operating noises; determine needed action.
  • Verify the need for service or repair of HVAC systems based on unusual visual, smell, and touch conditions; determine needed action.
  • Identify system type and components (cycling clutch orifice tube – CCOT, expansion valve) and conduct performance test(s) on HVAC systems; determine needed action.
  • Retrieve diagnostic codes; determine needed action.

Complete NATEF tasks related to A/C System and Components as listed below.

Objectives:

  • A/C System - General
  • Compressor and Clutch
  • Evaporator, Condenser, and Related Components

Complete NATEF tasks related to Heating and Engine Cooling Systems as listed below.

Objectives:

  • Identify causes of outlet air temperature control problems in the HVAC system; determine needed action.
  • Identify window fogging problems; determine needed action.
  • Perform engine cooling system tests for leaks, protection level, contamination, coolant level, coolant type, temperature, and conditioner concentration; determine needed action.
  • Inspect engine cooling and heating system hoses, lines, and clamps; determine needed action.
  • Inspect and test radiator, pressure cap, and coolant recovery system (surge tank); determine needed action.
  • Inspect water pump; determine needed action.
  • Inspect and test thermostats, by-passes, housings, and seals; determine needed repairs.
  • Recover, flush, and refill with recommended coolant/additive package; bleed cooling system.
  • Inspect thermostatic cooling fan system (hydraulic, pneumatic, and electronic) and fan shroud; replace as needed.
  • Inspect and test heating system coolant control valve(s) and manual shut- off valves; determine needed action.
  • Inspect and flush heater core; determine needed action.

Complete NATEF tasks related to Operating Systems and Related Controls as listed below.

Objectives:

  • Electrical
  • Air/Mechanical

Complete NATEF tasks related to Refrigerante Recovery, Recycling, and Handling as listed below. These NATEF tasks should be accomplished in accordance with appropriate EPA regulations and SAE "J" standards.

Objectives:

  • Maintain and verify correct operation of certified equipment.
  • Identify and recover A/C system refrigerant.
  • Recycle or properly dispose of refrigerant.
  • Handle, label, and store refrigerant.
  • Test recycled refrigerant for non-condensable gases.