SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSCHEVROLET2001CHEVY EXPRESS G2500, VAN CARGO EXTENDED, 5.7 R, L31/KL8REPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 737 (HEATING, VENTILATION AND AIR CONDITIONING)REPAIR INSTRUCTIONSHVAC MODULE ASSEMBLY REPLACEMENTINSTALLATION PROCEDURE
2001 Chevrolet Chevy Express G2500, Van Cargo Extended, 5.7 R, L31/KL8

Installation Procedure

2001 Chevrolet Chevy Express G2500, Van Cargo Extended, 5.7 R, L31/KL8SECTION Installation Procedure
WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
    Fig 1: HVAC Module Air Inlet, Drain & Plumbing Seals
    GM179036Courtesy of GENERAL MOTORS CORP.
  1. Install new air inlet, drain and plumbing seals to the HVAC module.
    2. Fig 2: Dashmat, Module Drain Seal, Hvac Module & LH Retaining Bolt
    GM296213Courtesy of GENERAL MOTORS CORP.
  2. Carefully install the HVAC module to the vehicle in the following SEQUENCE.
      IMPORTANT: Ensure that the cut-outs on the dash mat are properly aligned so that the air inlet, drain, and plumbing seals are seated directly against the cowl and not the dashmat.
    1. Inspect the dashmat (1) for proper alignment to the cowl. Align if necessary.

      The opening in the dashmat for the HVAC module drain should be aligned so that the drain opening in the cowl is approximately centered in the dash mat opening; allowing ample room for the module drain seal (2) to fully seat against the cowl.

    2. ALIGN the heater core joint fitting, the condenser joint fitting, the HVAC module drain and the HVAC module studs to the corresponding openings on the cowl.
    3. INSERT the LH stud into the cowl FIRST, then the module drain, then the RH stud.
    4. Install the HVAC module LH retaining bolt to the I/P upper support beam module net locating hole (3).
      5. NOTE: Refer to Fastener Notice in Cautions and Notices.
    5. Install the HVAC module RH retaining bolt to the I/P upper support beam.

      Tighten:  Tighten the bolts to 10 N.m (89 lb in).

      6. IMPORTANT: To prevent possible water leaks or wind/road noise from entering the vehicle passenger compartment, DO NOT reuse the old HVAC module retaining and sealing nuts.
    6. Install the HVAC module new retaining and sealing nuts.
    7. Tighten the HVAC module retaining and sealing nuts.

      Tighten:  Tighten the nuts to 10 N.m (89 lb in).

    3. Fig 3: Windshield Defroster Duct & Screws
    GM95643Courtesy of GENERAL MOTORS CORP.
  3. Install and align the windshield defroster duct to the HVAC module opening and the I/P upper support beam.
  4. Install the windshield defroster duct LH retaining screw (net locating hole).
  5. Install the windshield defroster duct RH retaining screw.

    Tighten:  Tighten the screws to 10 N.m (89 lb in).

    6. Fig 4: Vacuum Electric Solenoid & Electrical Connector
    GM295337Courtesy of GENERAL MOTORS CORP.
  6. Connect the electrical connector to the vacuum electric solenoid.
    7. Fig 5: HVAC Module Vacuum Harness & I/P Harness Vacuum Supply Line
    GM297262Courtesy of GENERAL MOTORS CORP.
  7. Connect the I/P harness vacuum supply line (1) to the HVAC module vacuum harness (2).
    8. Fig 6: Blower Motor Control Module & Electrical Connector
    GM295319Courtesy of GENERAL MOTORS CORP.
  8. Install the blower motor. Refer to Blower Motor Replacement .
  9. Connect the electrical connector to the blower motor control module.
    10. Fig 7: Rear RH Floor Air Outlet Duct
    GM95654Courtesy of GENERAL MOTORS CORP.
  10. Position and align the RH floor air outlet duct - rear to the HVAC module, then push firmly and evenly to secure the duct.
    11. Fig 8: RH Side Driveline Tunnel & Carpet Air Outlet Duct
    GM297307Courtesy of GENERAL MOTORS CORP.
  11. Secure the carpet air outlet duct to the RH floor air outlet duct - rear.

    Use a rotating motion to secure the carpet air outlet duct to the floor air outlet duct - rear.

  12. Position the front floor carpet to the RH side of the driveline tunnel.
    13. Fig 9: RH Floor Air Outlet Duct & Screws
    GM95647Courtesy of GENERAL MOTORS CORP.
  13. Install the RH floor air outlet duct to the HVAC module.
  14. Install the RH floor air outlet duct retaining screws.

    Tighten:  Tighten the screws to 1.6 N.m (14 lb in).

    15. Fig 10: RH Temperature Actuator & Electrical Connector
    GM295333Courtesy of GENERAL MOTORS CORP.
  15. Connect the electrical connector to the RH temperature actuator.
  16. Connect the sunload sensor electrical connector.
    17. Fig 11: RH Side Window Defogger & Lower Outlet Duct
    GM95658Courtesy of GENERAL MOTORS CORP.
  17. Install the passenger SIR bracket and the passenger knee bolster bracket. Refer to Bracket Replacement - Knee Bolster (Passenger) or Bracket Replacement - Knee Bolster (Driver) or Bracket Replacement - Knee Bolster (Driver Outer) in Instrument Panel, Gages and Console.
  18. Install the RH side window defogger outlet duct - lower.
    1. Use a twisting motion to secure the defogger outlet duct - lower to the defogger outlet duct - upper, then to the windshield defroster duct.
    2. Install the defogger outlet duct - lower retaining tabs to the passenger SIR bracket.
    19. Fig 12: Rear LH Floor Air Outlet Duct
    GM95652Courtesy of GENERAL MOTORS CORP.
  19. Position and align the LH floor air outlet duct - rear to the HVAC module, then push firmly and evenly to secure the duct.
    20. Fig 13: LH Floor Air Outlet Duct & Retaining Screws
    GM95646Courtesy of GENERAL MOTORS CORP.
  20. Install the LH floor air outlet duct to the HVAC module.
  21. Install the LH floor air outlet duct retaining screws.

    Tighten:  Tighten the screws to 1.6 N.m (14 lb in).

  22. Install the I/P center support bracket and the ignition switch housing bracket. Refer to Bracket Replacement - Instrument Panel (I/P) Center Support in Instrument Panel, Gages and Console.
    23. Fig 14: Locating Actuator Connector
    GM295297Courtesy of GENERAL MOTORS CORP.
  23. Connect the electrical connector to the LH temperature actuator.
  24. Connect the DRL sensor electrical connector, if equipped.
    25. Fig 15: DRL Sensor Electrical Connector
    GM95644Courtesy of GENERAL MOTORS CORP.
  25. Install the inside air temperature sensor aspirator duct muffler.

    Use a twisting motion to secure the duct muffler.

    26. Fig 16: Inside Air Temperature Sensor Aspirator Duct
    GM95661Courtesy of GENERAL MOTORS CORP.
  26. Install the inside air temperature sensor aspirator duct.
    1. Use a twisting motion to secure the duct to the duct muffler.
    2. Install the duct retaining tab to the ignition switch housing bracket.
    27. Fig 17: LH Side Window Defogger & Lower Outlet Duct
    GM95655Courtesy of GENERAL MOTORS CORP.
  27. Install the LH side window defogger outlet duct - lower.
    1. Use a twisting motion to secure the defogger outlet duct - lower to the defogger outlet duct - upper, then to the windshield defroster duct.
    2. Install the push-in retainer.
  28. Install the I/P upper trim pad. Refer to Trim Pad Replacement - Instrument Panel (I/P) Upper in Instrument Panel, Gages and Console.
    29. Fig 18: HVAC Module Drain Tube
    GM296218Courtesy of GENERAL MOTORS CORP.
  29. Install the HVAC module drain tube to the module.
    • Ensure that the drain tube is fully seated to the HVAC module.
    • Align the drain tube to contact the cowl as shown (1).
  30. Remove the cap or tape from the accumulator hose, evaporator tube - rear and the evaporator.
  31. Install a new O-ring. Refer to O-Ring Replacement .
    32. Fig 19: Accumulator Hose, Evaporator & Bolt
    GM621748Courtesy of GENERAL MOTORS CORP.
  32. Install the accumulator hose and evaporator tube - rear to the evaporator.
  33. Install the accumulator hose to evaporator retaining bolt.

    Tighten:  Tighten the bolt to 16 N.m (12 lb ft).

    34. Fig 20: Heater Core, Retaining Bolt & Heater Pipe
    GM621745Courtesy of GENERAL MOTORS CORP.
  34. Remove the cap or plug from the heater pipe assembly and the heater core.
  35. Install new sealing washers. Refer to Sealing Washer Replacement .
  36. Connect the heater pipe assembly to the heater core.
  37. Install the heater pipe assembly retaining bolt.

    Tighten:  Tighten the bolt to 16 N.m (12 lb ft).

  38. Install the RH air injection pipe.
  39. Install the RH air injection pipe to RH cylinder head bolts.

    Tighten:  Tighten the bolts to 20 N.m (15 lb ft).

    40. Fig 21: RH Air Injection Check Valve To RH/LH Cylinder Head & Bolts
    GM63229Courtesy of GENERAL MOTORS CORP.
  40. Install the RH air injection check valve to LH cylinder head bolt.

    Tighten:  Tighten the bolt to 20 N.m (15 lb ft).

  41. Connect the hose and hose clamp to the RH air injection check valve.
    42. Fig 22: Heater Pipe Bracket & Cowl
    GM621749Courtesy of GENERAL MOTORS CORP.
  42. Install the heater pipe bracket into position.
  43. Install the heater pipe bracket retaining nut.

    Tighten:  Tighten the nut to 10 N.m (89 lb in).

  44. Install the intake manifold. Refer to Intake Manifold Replacement in Engine Mechanical 5.7-L.
  45. Install the battery heat shield. Refer to Battery Heat Shield Replacement in Engine Electrical.
  46. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .
  47. Leak test the fittings of the component using J 39400-A  . See Special Tools and Equipment .
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.