GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC Suburban - 2WD 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Air Conditioning Evaporator Core Replacement

Removal Procedure

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.
  2. Drain the engine coolant. Refer to Cooling System Draining and Filling .
  3. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging .
  4. Remove the instrument panel. Refer to Instrument Panel Compartment Replacement in Instrument Panel, Gauges and Console.
  5. Disconnect the electrical connectors, as necessary.
  6. Remove the floor air outlet. Refer to Floor Air Outlet Replacement in Heating and Ventilation (Non-A/C).
  7. On diesel engines only, remove the powertrain control module.
  8. Remove the hinge pillar trim panels. Refer to Body Hinge Pillar Trim Panel Replacement in Interior Trim.
  9. Remove the blower motor cover.

    10. Object Number: 258006 Size: SH
  10. Remove the blower motor (5). Refer to Blower Motor and Fan Replacement .
  11. Remove the steering column. Refer to the appropriate procedure from the following list:
    12. •  Steering Column Replacement in Steering Wheel and Column -- Standard
    •  Steering Column Replacement in Steering Wheel and Column -- Tilt
  12. Tilt back the instrument panel assembly. Refer to Actuator Replacement - Front and Rear Vertical.
  13. Remove the coolant recovery reservoir. Refer to Coolant Recovery Reservoir Replacement in Engine Cooling.
  14. Disconnect the heater hoses. Refer to Heater Hoses Replacement or Heater Hoses Replacement - Auxiliary in Heating and Ventilation (Non-A/C).
  15. Disconnect the evaporator tube. Refer to Evaporator Tube Replacement .
  16. Remove the accumulator. Refer to Air Conditioning Accumulator Replacement .

    17. Object Number: 258009 Size: SH
  17. Remove the screws (1, 4).
  18. Remove the nut (2).

    19. Object Number: 258006 Size: SH
  19. Remove the screw (2).
  20. Remove the module assembly (2).

    21. Ask an assistant for help in removing the module assembly, if necessary.

  21. Remove the seven screws in order to remove the cover plate (8) on the bottom of the evaporator case from the module assembly.
  22. Remove the heater core and the seal from the module assembly.
  23. Remove the four screws in order to remove the case cover (6) of the evaporator from the module assembly.
  24. Remove the evaporator core.

Installation Procedure
  1. Install the evaporator core.

    2. If the evaporator core is being replaced, add oil. Refer toRefrigerant Recovery and Recharging .


    Object Number: 258006 Size: SH
  2. Install the four screws that hold the case cover (6) of the evaporator to the module assembly.
  3. Install the heater core and the seal into the module assembly.
  4. Install the seven screws that hold the cover plate (8) on the bottom of the evaporator case to the module assembly.
  5. Install the module assembly (2).

    6. Ask an assistant for help in installing the module assembly, if necessary.

  6. Install the screw (1).

    7. Object Number: 258009 Size: SH
  7. Install the nut (2).
  8. Install the screws (1, 4).

    9. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  9. Tighten the following fasteners:

    10. Tighten

        • Tighten the module mounting screw to 11 N·m (97 lb in).
        • Tighten the nut (2) to 2.8 N·m (25 lb in).
        • Tighten the screws (1, 4) to 1.9 N·m (17 lb in).
  10. Install the accumulator. Refer to Air Conditioning Accumulator Replacement .
  11. Connect the evaporator tube. Refer to Evaporator Tube Replacement .
  12. Connect the heater hoses. Refer to Heater Hoses Replacement or Heater Hoses Replacement - Auxiliary in Heating and Ventilation (Non-A/C).
  13. Install the coolant recovery reservoir. Refer to Coolant Recovery Reservoir Replacement in Engine Cooling.
  14. Install the instrument panel. Refer to Instrument Panel Compartment Replacement in Instrument Panel, Gauges and Console.
  15. Install the steering column. Refer to the appropriate procedure from the following list:
    16. •  Steering Column Replacement in Steering Wheel and Column -- Standard
    •  Steering Column Replacement in Steering Wheel and Column -- Tilt

    Object Number: 258006 Size: SH
  16. Install the blower motor (5).
  17. Install the blower motor cover.
  18. Install the hinge pillar trim panels. Refer to Body Hinge Pillar Trim Panel Replacement in Interior Trim.
  19. Install the powertrain control module and the mounting tray.
  20. Install the floor air outlet. Refer to Floor Air Outlet Replacement in Heating and Ventilation (Non-A/C).
  21. Connect the electrical connectors, as necessary.
  22. Add the engine coolant.
  23. Connect the negative battery cable.
  24. Charge the system. Refer to Refrigerant Recovery and Recharging
  25. Inspect the system for leaks. Refer to Leak Testing .