Nissan Sentra Service Manual: Heating and cooling unit assembly

Exploded view

With air conditioning

1. Defroster seal
2. Center ventilator seal
3. Upper distribution module
4. Side ventilator seal (LH)
5. Blower motor
6. Blower unit
7. Intake door motor
8. Power transistor
9. Power transistor wiring harness
10. Front floor duct (lh)
11. Vent and defroster linkage
12. Mode door motor
13. Heater core
14. Heater core pipes grommet
15. Heating and cooling unit
16. In-cabin microfilter
17. In-cabin microfilter cover
18. Air mix door motor (lh) (automatic a/c only)
19. Vent and defroster linkage
20. Front floor duct (rh)
21. Air mix door motor (RH)
22. Expansion valve
23. Evaporator
24. Aspirator (automatic a/c only)
25. Vent and defroster linkage
26. Side ventilator seal (rh)

Without air conditioning

1. Defroster seal
2. Center ventilator seal
3. Upper distribution module
4. Side ventilator seal (lh)
5. Blower motor
6. Blower unit
7. Intake door motor
8. Power transistor
9. Power transistor wiring harness
10. Front floor duct (LH)
11. Vent and defroster linkage
12. Mode door motor
13. Heater core
14. Heater core pipes grommet
15. Heating and cooling unit
16. In-cabin microfilter
17. In-cabin microfilter cover
18. Front floor duct (RH)
19. Air mix door motor
20. Vent and defroster linkage
21. Side ventilator seal (RH)

Heating and cooling unit assembly

Heating and cooling unit assembly : removal and installation

NOTE:

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

REMOVAL

1. Discharge the refrigerant. Refer to HA-23, "Recycle Refrigerant".
2. Drain the cooling system. Refer to CO-12, "Changing Engine Coolant".
3. Remove the instrument panel assembly. Refer to IP-14, "Removal and Installation".
4. Remove the steering column. Refer to ST-12, "Removal and Installation".
5. Remove the center console. Refer to IP-17, "Removal and Installation".
6. Remove the wiper drive assembly. Refer to WW-62, "Removal and Installation".
7. Remove the steering member bolt (A).

(1): Windshield glass

NOTE:

The steering member bolt (A) can be found near the drivers side cowl area in the engine compartment.

8. Remove the push nut (A) from the expansion valve insulator (1) and reposition.

9. Remove the bolt (A) that retains the low-pressure flexible hose and high-pressure pipe to 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.

10. Disconnect the low-pressure pipe and high-pressure pipe from the expansion valve.
11. Disconnect the heater hoses from the heater core pipes.
12. Remove the remaining steering member bolts.
13. Disconnect the harness connectors from the heating and cooling unit assembly and steering member.
14. Remove the heating and cooling unit assembly and steering member as an assembly from the vehicle.
15. Separate the heating and cooling unit assembly from the steering member.

INSTALLATION

Installation is in the reverse order of removal.

CAUTION:

• Do not reuse O-rings.

• Apply A/C oil to new O-rings for installation.

• After charging refrigerant, check for leaks. Refer to HA-21, "Leak Test".

Heater core

Heater core : removal and installation

REMOVAL

The heater core is not serviced separately and must be replaced with the heating and cooling unit assembly.

Refer to HA-43, "HEATING AND COOLING UNIT ASSEMBLY : Removal and Installation".

Evaporator

Evaporator : removal and installation

REMOVAL

The evaporator is not serviced separately and must be replaced with the heating and cooling unit assembly.

Refer to HA-45, "EVAPORATOR : Removal and Installation".

Expansion valve

Expansion valve : removal and installation

REMOVAL

1. Discharge the refrigerant. Refer to HA-23, "Recycle Refrigerant".
2. Remove the push nut (A) from the expansion valve insulator (1) and reposition.

3. Remove the bolt (A) that retains the low-pressure flexible hose and high-pressure pipe to the expansion valve.

4. Disconnect the low-pressure pipe and high-pressure pipe from the expansion valve.
5. Remove the expansion valve bolts.
6. 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 expansion valve O-rings for installation.

• After charging refrigerant, check for leaks. Refer to HA-21, "Leak Test".

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