GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2001 🢒 Regal (China) 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Two Stage Orifice Replacement

Removal Procedure
  1. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging in HVAC.
  2. Remove the air cleaner assembly. Refer to in Air Cleaner Assembly Replacement Engine Controls.
  3. Remove the vacuum brake booster. Refer to Power Vacuum Brake Booster Replacement in Hydraulic Brakes.
  4. Remove the liquid line/suction line bracket.

    5. Object Number: 476751 Size: SH
  5. Remove the two stage orifice harness retaining nut (1).
  6. Disconnect the electrical connector (2).

    7. Object Number: 476749 Size: SH
  7. Remove the evaporator line nut (1) at the two stage orifice.
  8. Remove the condenser line nut (2) at the two stage orifice.
  9. Remove the two stage orifice (3).
  10. Remove and discard the O-ring.

Installation Procedure

    Important: The new O-ring seals must be lubricated with mineral base 525 viscosity refrigerant oil.

  1. Install the new O-ring seals onto the condenser and evaporator lines. Refer to O-Ring Replacement in HVAC.

    2. Object Number: 476749 Size: SH
  2. Install the two stage orifice (3).
  3. Connect the condenser line nut (2) at the two stage orifice, hand tight .
  4. Connect the evaporator line nut (1) at the two stage orifice, hand tight.

    5. 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.

  5. Install the condenser line nut (2) at the two stage orifice.

    6. Tighten
    Tighten the condenser line nut to 27 N·m (20 lb ft).

  6. Install the evaporator line nut (1) at the two stage orifice.

    7. Tighten
    Tighten the evaporator line nut to 36 N·m (26 lb ft).


    Object Number: 476751 Size: SH
  7. Connect the electrical connector (2).
  8. Install the two stage orifice harness retaining nut (1).

    9. Tighten
    Tighten the two stage harness nut to 3.3 N·m (29 lb in).

  9. Install the liquid line/suction line bracket.
  10. Install the vacuum brake booster. Refer to Power Vacuum Brake Booster Replacement in Hydraulic Brakes.
  11. Install the air cleaner assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls.
  12. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging in HVAC.
  13. Leak test the filling(s) of the repaired or reinstalled component using J 39400 .