GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  2. Remove the thermostat bypass pipe. Refer to Thermostat Bypass Pipes Replacement in Engine Cooling.

  3. Object Number: 395311  Size: SH
  4. Disconnect the inlet heater hose (1) from the inlet pipe (2).

  5. Object Number: 395308  Size: SH
  6. Disconnect the electrical harness from the inlet pipe bracket.

  7. Object Number: 395307  Size: SH
  8. Remove the heater inlet pipe nut.
  9. Remove the inlet pipe from the thermostat housing.
  10. Remove and discard the O-ring seal.

Installation Procedure


    Object Number: 395307  Size: SH
  1. Install a new O-ring seal on the inlet pipe.
  2. Install the inlet pipe to the thermostat housing.
  3. 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.

  4. Install the heater inlet pipe nut.
  5. Tighten
    Tighten the nut to 7 N·m (62 lb in).


    Object Number: 395308  Size: SH
  6. Connect the electrical harness to the inlet pipe bracket.

  7. Object Number: 395311  Size: SH
  8. Connect the inlet heater hose (1) to the inlet heater pipe (2).
  9. Install the thermostat bypass pipe. Refer to Thermostat Bypass Pipes Replacement in Engine Cooling.
  10. Refill the coolant. Refer to Cooling System Draining and Filling in Engine Cooling.