Nissan Maxima Service and Repair Manual: Heater & cooling unit assembly

Exploded View

1. Wiring harness
2. Mode door motor
3. Upper floor connecting duct (LH)
4. Air mix door motor (driver side)
5. Heater core pipes cover
6. Heater core
7. In-cabin microfilter
8. Filter cover
9. Blower motor
10. Intake door motor
11. Blower unit
12. Upper floor connecting duct (RH)
13. Air mix door motor (passenger side)
14. Expansion valve
15. Evaporator
16. Heating and cooling unit assembly

NOTE: When removing components such as hoses, tubes/lines, etc., cap or plug openings to prevent fluid from spilling.

HEATER & COOLING UNIT ASSEMBLY

HEATER & COOLING UNIT ASSEMBLY : Removal and Installation

REMOVAL

CAUTION: Before servicing, turn the ignition switch off, disconnect both battery terminals and wait at least three minutes.

1. Discharge the refrigerant. Refer to HA-28, "Recycle Refrigerant".
2. Drain the engine coolant. Refer to CO-11, "Changing Engine Coolant".
3. Disconnect the battery negative and positive terminals.
4. Remove the front wiper drive assembly. Refer to WW-78, "FRONT WIPER ARMS : Removal and Installation".
5. Remove the strut tower bar. Refer to FSU-13, "Exploded View".
6. Disconnect the heater hoses from the heater core pipes.
7. Disconnect the high-pressure pipe and low-pressure pipe from the expansion valve. Refer to HA-42, "Exploded View". CAUTION: Cap or wrap the pipe joint with a suitable material such as vinyl tape to avoid the entry of air.
8. Remove the instrument panel assembly. Refer to IP-11, "Removal and Installation".
9. Remove the steering column assembly. Refer to ST-23, "Removal and Installation".
10. Disconnect the drain hose.
11. Remove the interior fuse block (J/B). Refer to PG-62, "Terminal Arrangement".
12. Remove the LH, RH and center connector ducts. Refer to VTL-11, "REAR FLOOR DUCTS : Removal and Installation".
13. Remove the steering member center stay.
14. Remove the heating and cooling unit assembly attached to the steering member as one assembly from the vehicle.
15. Remove the blower unit from the heating and cooling unit and steering member assembly.
16. Remove the heating and cooling unit from the steering member.

INSTALLATION

Installation is in the reverse order of removal.

HEATER CORE

HEATER CORE : Removal and Installation

REMOVAL

1. Remove the heating and cooling unit assembly. Refer to HA-47, "HEATER & COOLING UNIT ASSEMBLY : Removal and Installation".
2. Remove the heater core pipes cover. Refer to HA-47, "Exploded View".
3. Remove the heater core.

INSTALLATION

Installation is in the reverse order of removal.

CAUTION: Make sure that the aspirator hose is securely attached to the aspirator on the upper floor connecting duct LH.

EVAPORATOR

EVAPORATOR : Removal and Installation 

REMOVAL

1. Remove the heating and cooling unit assembly. Refer to HA-28, "Recycle Refrigerant".
2. Remove the upper floor connecting duct RH. Refer to HA-47, "Exploded View".
3. Remove the evaporator.
4. Remove the expansion valve from the evaporator.

• Remove the intake sensor.

CAUTION:

• Mark the mounting position of the intake sensor.

INSTALLATION

Installation is in the reverse order of removal.

CAUTION:

• Do not reuse O-rings.
• Apply A/C oil to the new O-rings for installation.
• After charging refrigerant, check for leaks.

EXPANSION VALVE

EXPANSION VALVE : Removal and Installation for Expansion Valve

REMOVAL

1. Discharge the refrigerant. Refer to HA-28, "Recycle Refrigerant".
2. Remove the hoodledge covers (LH/RH).
3. Remove the strut tower bar. Refer to FSU-13, "Exploded View".
4. Remove the cowl top grille. Refer to EXT-21, "Removal and Installation".
5. Remove the lower cowl top extension RH.
6. Disconnect the high-pressure pipe and low-pressure pipe from the expansion valve. CAUTION: Cap or wrap the joint of the pipe with suitable material such as vinyl tape to avoid the entry of air.
7. Remove the expansion valve.

INSTALLATION

Installation is in the reverse order of removal.

CAUTION:

• Do not reuse O-rings.
• Apply A/C oil to the new O-rings for installation.
• After charging refrigerant, check for leaks