GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2009 🢒 G8 🢒 HVAC 🢒 Heating, Ventilation, and Air Conditioning 🢒 Air Conditioning Evaporator Thermal Expansion Valve Replacement

Removal Procedure

    Warning: Refer to Safety Glasses Warning in the Preface section.

  1. Remove the radiator air baffle and deflector. Refer to Radiator Air Upper Baffle and Deflector Replacement.
  2. Remove the engine cover. Refer to Engine Cover Replacement or Engine Cover Replacement.
  3. Recover the refrigerant Refer to Refrigerant Recovery and Recharging.

    4. Warning: Refer to Battery Disconnect Warning in the Preface section.

  4. Disconnect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection.
  5. Remove the air filter assembly. Refer to Air Cleaner Assembly Replacement or Air Cleaner Assembly Replacement.

    6. Object Number: 2040644 Size: SH
  6. Disconnect the vacuum hose (1) and the vacuum brake booster check valve (3) from the vacuum brake booster (2).
  7. Detach the vacuum hose (1) from the bulkhead mounted vacuum hose retaining bracket (4) and position aside.

    8. Object Number: 2034102 Size: SH
  8. Remove the remote battery positive post cover (1).

    9. Object Number: 2040647 Size: SH
  9. Remove the remote battery positive post to wiring harness retaining bolt (1).
  10. Remove the starter motor power cable (2) and position aside.

    11. Object Number: 1957871 Size: SH
  11. Remove the suction pipe upper to suction pipe lower retaining nut (1).

    12. Object Number: 1955641 Size: SH
  12. Remove the suction pipe/liquid pipe retaining clip to left front chassis rail retaining bolt (3).
  13. Detach the liquid pipe (1) from the suction pipe/liquid pipe retaining clip (2).

    14. Object Number: 1950845 Size: SH
  14. Disconnect the suction pipe upper (1) from suction pipe lower (2).

    15. Note: The sealing washer (3) is a single use item and must be discarded after use.

  15. Remove the sealing washer (3). Refer to Sealing Washer Replacement.

    16. Discard the sealing washer

    Note: Cover any opening of the A/C system with a suitable cap or tape immediately, to prevent absorption of moisture from the atmosphere.

  16. Cap or plug the suction pipe upper (1) and the suction pipe lower (2).

    17. Object Number: 2040649 Size: SH
  17. Remove the suction pipe/liquid pipe pad to TX valve retaining nut (1).

    18. Object Number: 2040651 Size: SH
  18. Disconnect the suction pipe/liquid pipe pad (3) from the TX valve (1).

    19. Note: The sealing washers (2) are a single use item and must be discarded after use.

  19. Remove the sealing washers (2). Refer to Sealing Washer Replacement.

    20. Discard the sealing washers

    Note: Cover any opening of the A/C system with a suitable cap or tape immediately, to prevent absorption of moisture from the atmosphere.

  20. Cap or plug the suction pipe (4) and liquid pipe (5).

    21. Object Number: 1950873 Size: SH

    Note: Using a suitable tool, unscrew the TX valve to evaporator pad retaining screws (1).

  21. Remove the TX valve to evaporator pad retaining screws (1).

    22. Object Number: 1955649 Size: SH

    Note: If required, reinstall the suction pipe/liquid pipe to TX valve retaining nut to assist in the removal of the TX valve.

    Note: Place the TX Valve in a plastic bag to avoid any contamination from air born dirt or moisture.

  22. Remove the TX valve (3) from the evaporator pad (1).

    23. Note: The sealing washers (2) are single use items and must be discarded after use.

  23. Remove the sealing washers (2) from the evaporator pad (1). Refer to Sealing Washer Replacement.

    24. Discard the sealing washers

    Note: Cover any opening of the A/C system with a suitable cap or tape immediately, to prevent absorption of moisture from the atmosphere.

  24. Cap or plug the evaporator pad (1) and the TX valve (3).

Installation Procedure

    Object Number: 1955649 Size: SH
  1. Remove the plugs or caps from the thermal expansion (TX) valve (3) and the evaporator pad (1).

    2. Note: DO NOT coat the NEW sealing washers (2) with oil, they must be fitted dry. The use of mineral oil will render the sealing washers (2) useless, as the sealing washers (2) WILL swell causing refrigerant to leak out.

  2. Install NEW sealing washers (2) to the evaporator pad (1). Refer to Sealing Washer Replacement.
  3. Connect the TX valve (3) to the evaporator pad (1).

    4. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 1950873 Size: SH
  4. Install TX valve to evaporator pad retaining screws (1) and tighten to 4 N·m (35 lb in).

    5. Object Number: 2040651 Size: SH
  5. Remove the plugs or caps from the suction pipe (4), liquid pipe (5) and the TX valve (1).

    6. Note: DO NOT coat the NEW sealing washers (2) with oil, they must be fitted dry. The use of mineral oil will render the sealing washers (2) useless, as the sealing washers (2) WILL swell causing refrigerant to leak out.

  6. Install NEW sealing washers (2). Refer to Sealing Washer Replacement.
  7. Position the suction pipe/liquid pipe pad (3) to the TX Valve (1).

    8. Object Number: 2040649 Size: SH
  8. Install the suction pipe/liquid pipe pad to TX valve retaining nut (1) and tighten to 22 N·m(16 lb ft).

    9. Object Number: 1957873 Size: SH
  9. Remove the plugs or caps to the suction pipe upper (1) and the suction pipe lower (2).

    10. Note: DO NOT coat the NEW sealing washer (3) with oil, they must be fitted dry. The use of mineral oil will render the sealing washer (3) useless, as the sealing washer (3) WILL swell causing refrigerant to leak out.

  10. Install a NEW sealing washer (3). Refer to Sealing Washer Replacement.
  11. Install the suction pipe upper (1) to the suction pipe lower (2).

    12. Object Number: 1955641 Size: SH
  12. Attach the liquid pipe (1) from the suction pipe/liquid pipe retaining clip (2).
  13. Install the suction pipe/liquid pipe retaining clip to left front chassis rail retaining bolt (3).

    14. Object Number: 1957875 Size: SH
  14. Install the suction pipe upper to suction pipe lower retaining nut (1) and tighten to 22 N·m( 16 lb ft).

    15. Object Number: 2034103 Size: SH
  15. Install the starter motor positive cable (2) to the remote battery positive post (3).
  16. Install the remote battery positive post to wiring harness retaining bolt (1) and tighten to 15 N·m (11 lb ft).

    17. Object Number: 2034102 Size: SH

    Note: Make sure the clips on the remote battery positive post cover (1) are engaged to avoid an induced rattle condition.

  17. Install the remote battery positive post cover (1).

    18. Object Number: 2040644 Size: SH
  18. Connect the vacuum hose (1) and the vacuum brake booster check valve (3) to the vacuum brake booster (2).
  19. Attach the vacuum hose (1) to the bulkhead mounted vacuum hose retaining bracket (5).
  20. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging.
  21. Install the radiator air baffle and deflector. Refer to Radiator Air Upper Baffle and Deflector Replacement.
  22. Install the air filter assembly. Refer to Air Cleaner Assembly Replacement or Air Cleaner Assembly Replacement.
  23. Install the engine cover. Refer to Engine Cover Replacement or Engine Cover Replacement.
  24. Connect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection.
  25. Leak test the thermal expansion valve pipe connections. Refer to Leak Testing.