GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2000 🢒 Montana 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Air Conditioning Evaporator Core Replacement

Removal Procedure
  1. Remove the heater A/C module. Refer to HVAC Module Assembly Replacement .
  2. Release the heater A/C module vacuum harness from both of the harness retainers on the module case.

    3. Object Number: 400653 Size: SH
  3. Remove the air inlet housing.
  4. Remove the heater/defrost valve vacuum actuator from the blower module. Refer to Defroster Valve Actuator Replacement in HVAC System -- Manual.
  5. Remove the heater A/C module retaining screws.

    6. Object Number: 295357 Size: SH
  6. Release the retaining tab (1) and separate the upper and lower module halves.

    7. Object Number: 296249 Size: SH
  7. Remove the heater A/C module seal that is between the upper and lower modules.

    8. Start to remove the module case primary (blower motor side of case) seal (2) from the lower module case at the position shown (1).


    Object Number: 295362 Size: SH
  8. Remove the evaporator core.

    9. Object Number: 144107 Size: SH
  9. Remove and discard the evaporator core lower seals.

    10. Object Number: 144104 Size: SH
  10. Remove and discard the evaporator core upper seal.

    11. Object Number: 144106 Size: SH
  11. Remove and discard the evaporator core side seal.

    12. Object Number: 144102 Size: SH
  12. Remove and discard the evaporator core water core filter.

Installation Procedure

    Object Number: 144102 Size: SH
  1. Install a new water core filter to the new evaporator core.

    2. Object Number: 144106 Size: SH
  2. Install a new side seal to the evaporator core. Line the evaporator core side seal up with the corners of the evaporator core.

    3. Object Number: 144104 Size: SH
  3. Install a new upper seal to the evaporator core.

    4. Object Number: 144107 Size: SH
  4. Install two new lower seals to the evaporator core.

    5. Locate the seals at the outer corners (or edges) of the evaporator core.


    Object Number: 296253 Size: SH
  5. Install new case seals to the lower module case.

    6. Start to install the lower case seal (2) to the lower case from the position shown (1).


    Object Number: 295362 Size: SH
  6. Install the evaporator core into the lower module case.

    7. Important: Inspect the condition of the retaining tab on the upper module case prior to installing to the lower module case. If the retaining tab is broken or damaged, install an external retaining clip (P/N 52458793, or equivalent).


    Object Number: 295357 Size: SH
  7. Align and install the upper module case to the lower module case.

    8. Align and secure the retaining tab (1) on the upper module case to the retaining slot on the lower module case

    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.

  8. Install the heater A/C module retaining screws.

    9. Tighten
    Tighten the screws to 1.5 N·m (13 lb in).

  9. Install the heater/defrost vacuum actuator valve. Refer to Defroster Valve Actuator Replacement in HVAC System -- Manual.

    10. Object Number: 400653 Size: SH
  10. Install the air inlet housing.
  11. Install the air inlet retaining screws.

    12. Tighten
    Tighten the screws to 1.5 N·m (13 lb in).

  12. Install the heater A/C module vacuum harness to the harness retainers on the module case.
  13. Install the heater A/C module. Refer to HVAC Module Assembly Replacement .