Infiniti FX35, FX50 (S51). Manual - part 1135

HEATER & COOLING UNIT ASSEMBLY

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HEATER & COOLING UNIT ASSEMBLY

HEATER & COOLING UNIT ASSEMBLY : Removal and Installation

INFOID:0000000005249920

REMOVAL

1.

Set the temperature at 18.0

°

C (60

°

F).

2.

Disconnect the battery cable from the negative terminal.

3.

Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.

4.

Drain engine coolant from cooling system. Refer to 

CO-8, "Draining"

.

5.

Remove cowl top cover. Refer to 

EXT-22, "Exploded View"

.

6.

Remove engine cover. Refer to 

EM-27, "Exploded View"

.

7.

Disconnect one-touch joint between low-pressure pipe 1 (1) and
low-pressure pipe 2 (2) with disconnector (SST: 9253089916)
(A).

CAUTION:

Cap or wrap the joint of the A/C piping with suitable mate-
rial such as vinyl tape to avoid the entry of air.

8.

Disconnect one-touch joint between high-pressure pipe 1 (4)
and high-pressure pipe 2 (3) with disconnector (SST:
9253089908).

CAUTION:

Cap or wrap the joint of the A/C piping with suitable mate-
rial such as vinyl tape to avoid the entry of air.

9.

Remove clamps (A), and then disconnect heater hoses (1).

10. Remove instrument panel assembly. Refer to 

IP-11, "Exploded View"

.

11. Remove defroster nozzle and adaptor duct. Refer to 

VTL-11, "Exploded View"

.

12. Remove blower unit. Refer to 

HA-57, "Exploded View"

.

13. Remove mounting nuts (A), and then remove instrument stay (left) (1) and instrument stay (right) (2).

14. Disconnect drain hose from heater & cooling unit assembly.

49.

Foot door (right)

50.

J-nut

51. Max. cool door lever

52.

Defroster door lever

53.

Defroster door link

54. Max. cool door link

55.

Intake sensor

56.

Intake sensor bracket

57. Air mix door motor (passenger side)

58.

Air mix door adapter

59.

Heater & cooling unit case (right)

60. Max. cool door (right)

61.

Max. cool door (left)

62.

Air mix door (Slide door)

Refer to 

GI-4, "Components"

 for symbols in the figure.

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< REMOVAL AND INSTALLATION >

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HEATER & COOLING UNIT ASSEMBLY

15. Remove mounting bolts (A) from steering member (1).

16. Remove mounting bolts (A) from steering member (1).

17. Remove ground bolts (B) from steering member.
18. Remove steering column mounting nuts (C) and bolts (D). Refer to 

ST-18, "WITHOUT ELECTRIC

MOTOR : Exploded View"

 (WITHOUT ELECTRIC MOTOR) or 

ST-21, "WITH ELECTRIC MOTOR :

Exploded View"

 (WITH ELECTRIC MOTOR).

19. Remove harness connector and clips of vehicle harness from steering member.

20. Remove mounting bolts (A) from steering member (1).

21. Remove steering member mounting bolt (B).
22. Remove steering member, and then remove heater & cooling unit assembly.

INSTALLATION

Installation is basically the reverse order of removal.

CAUTION:

• Replace O-rings with new ones. Then apply compressor oil to them when installing.
• Female-side piping connection is thin and easy to deform. Slowly insert the male-side piping

straight in axial direction.

• Insert piping securely until a clicks is heard.
• After piping connection is completed, pull male-side piping by hand to make sure that connection

does not come loose.

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HEATER & COOLING UNIT ASSEMBLY

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• Check for leakages when recharging refrigerant.
NOTE:
• Refer to 

CO-9, "Refilling"

 when filling radiator with engine coolant.

• Recharge the refrigerant.

HEATER CORE

HEATER CORE : Removal and Installation

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REMOVAL

1.

Remove heater & cooling unit assembly. Refer to 

HA-51, "Exploded View"

.

2.

Remove mounting screws (A), and then remove heater pipe
cover (1).

3.

Remove mounting screws (B), and then remove foot duct (left)
(2).

4.

Slide heater core (3) to leftward (as shown in the figure).

INSTALLATION

Installation is basically the reverse order of removal.
NOTE:
Refer to 

CO-9, "Refilling"

 when filling radiator with engine coolant.

EVAPORATOR

EVAPORATOR : Removal and Installation

INFOID:0000000005249922

REMOVAL

1.

Remove low-pressure pipe 1 and high-pressure pipe 2.

2.

Slide evaporator (1) from heater & cooling unit assembly.

3.

Remove intake sensor (2) from evaporator, and then remove
evaporator.

4.

Remove mounting bolts (A), and then remove expansion valve
(1).

CAUTION:

Cap or wrap the joint of evaporator and expansion valve
with suitable material such as vinyl tape to avoid the entry
of air.

INSTALLATION

Installation is basically the reverse order of removal.

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< REMOVAL AND INSTALLATION >

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HEATER & COOLING UNIT ASSEMBLY

CAUTION:

• Replace O-rings with new ones. Then apply compressor oil to them when installing.
• Female-side piping connection is thin and easy to deform. Slowly insert the male-side piping

straight in axial direction.

• Insert piping securely until a click is heard.
• After piping connection is completed, pull male-side piping by hand to make sure that connection

does not come loose.

• O-rings differ from low-pressure flexible hose (high-pressure pipe 1) and low-pressure pipe 1 (high-

pressure pipe 2).

• Mark the mounting position of intake sensor bracket prior to removal so that the reinstalled sensor

can be located in the same position.

• Check for leakages when recharging refrigerant.

EXPANSION VALVE

EXPANSION VALVE : Removal and Installation

INFOID:0000000005249923

REMOVAL

1.

Remove low-pressure pipe 1 and high-pressure pipe 2. Refer to 

HA-40, "Exploded View"

.

2.

Remove mounting bolts (A), and then remove expansion valve
(1).

CAUTION:

Cap or wrap the joint of evaporator and expansion valve
with suitable material such as vinyl tape to avoid the entry
of air.

INSTALLATION

Installation is basically the reverse order of removal.

CAUTION:

• Replace O-rings with new ones. Then apply compressor oil to them when installing.
• O-rings are different from low-pressure pipe 1 (high-pressure pipe 1) and low-pressure pipe 2 (high-

pressure pipe 2).

• Check for leakages when recharging refrigerant.

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