For 1990-2009 cars

### Removal Procedure

1. Remove the HVAC module. Refer to HVAC Module Assembly Replacement .
2. Remove the heater core. Refer to Heater Core Replacement .
3. Remove the heater/defroster slave valve linkage from the heater valve.
4. Remove the heater case cover shroud.
5. Remove the heater valve from the module case.
6. Inspect the defroster valve for damage.

### Installation Procedure

1. Install the heater valve to the module case.
2. Install the heater case cover shroud.

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.

3. Install the mode/defroster valve case cover screws.

Tighten
Tighten the cover screws to 1 N·m (9 lb in).

4. Install the heater/defroster slave valve linkage to the heater valve.
5. Install the heater core. Refer to Heater Core Replacement .
6. Install the HVAC module. Refer to HVAC Module Assembly Replacement .