engine INFINITI QX56 2004 Factory Service Manual

HEATER & COOLING UNIT ASSEMBLY
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Rear A/C
Removal and InstallationEJS002D5
FRONT HEATER AND COOLING UNIT ASSEMBLY
Removal
1. Discharge the refrigerant from the A/C system. Refer to ATC-162, "Discharging Refrigerant" .
2. Drain the coolant from the engine cooling system. Refer to MA-12, "
DRAINING ENGINE COOLANT" .
3. Remove the cowl top extension. Refer to EI-18, "
Removal and Installation" .
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1. Rear heater and cooling unit assembly 2. Rear A/C pipes 3. Rear A/C heater core pipes
4. Rear heater core hose 5. Rear blower motor 6. Underfloor rear A/C pipes
7. Underfloor rear heater core pipes A. Bolt torque specifications B. Leak checking order (l - r)
C. Tightening torque D. Wrench size E. O-ring size
⇐Front
NOTE: The O-ring size 8 is the high-side and the O-ring size 16 is the low-side.

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4. Remove the exhaust system. Refer to EX-3, "Removal and Installation" .
5. Disconnect the front heater hoses from the front heater core.
6. Disconnect the high/low pressure pipes from the front expansion valve.
7. Move the two front seats to the rearmost position on the seat track.
8. Remove the instrument panel and console panel. Refer to IP-10, "
INSTRUMENT PANEL ASSEMBLY" .
9. Remove the steering column. Refer to PS-10, "
Removal and Installation" .
10. Disconnect the instrument panel wire harness at the RH and LH in-line connector brackets, and the fuse
block (J/B) electrical connectors. Refer to PG-40, "
Harness Layout" .
11. Disconnect the steering member from each side of the vehicle body.
12. Remove the front heater and cooling unit assembly with it attached to the steering member, from the vehi-
cle.
CAUTION:
Use care not to damage the seats and interior trim panels when removing the front heater and
cooling unit assembly with it attached to the steering member.
13. Remove the front heater and cooling unit assembly from the steering member.
Installation
Installation is in the reverse order of removal.
CAUTION:

Replace the O-ring of the low-pressure pipe and high-pressure pipe with a new one, and apply
compressor oil to it when installing it.

After charging the refrigerant, check for leaks.
NOTE:

Fill the engine cooling system with the specified coolant mixture. Refer to MA-13, "REFILLING ENGINE
COOLANT" .

Recharge the A/C system. Refer to ATC-162, "Evacuating System and Charging Refrigerant" .
REAR HEATER AND COOLING UNIT ASSEMBLY
Removal
1. Discharge the refrigerant from the A/C system. Refer to ATC-162, "Discharging Refrigerant" .
2. Drain the coolant from the engine cooling system. Refer to MA-12, "
DRAINING ENGINE COOLANT" .
3. Disconnect the rear heater core hoses from the rear heater core.
4. Disconnect the rear A/C pipes from the rear expansion valve.
5. Remove the rear RH interior trim panel. Refer to EI-34,
"Removal and Installation" .
6. Disconnect the following electrical connectors:

Rear blower motor

Rear blower motor resistor

Rear air mix door motor
7. Disconnect the ducts from the rear heater and cooling unit
assembly.
8. Remove the rear heater and cooling unit assembly.
Installation
Installation is in the reverse order of removal.
CAUTION:

Replace the O-ring of the low-pressure pipe and high-pressure pipe with a new one, and apply
compressor oil to it when installing it.

After charging the refrigerant, check for leaks.
NOTE:

Fill the engine cooling system with the specified coolant mixture. Refer to MA-13, "REFILLING ENGINE
COOLANT" .

Recharge the A/C system. Refer to ATC-162, "Evacuating System and Charging Refrigerant" .
LJIA0021E

HEATER CORE
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5. Remove the heater core.
NOTE:
If the in-cabin microfilters are contaminated from coolant leaking
from the heater core, replace the in-cabin microfilters with new
ones before installing the new heater core.
Installation
Installation is in the reverse order of removal.
REAR HEATER CORE
Removal
1. Partially drain the engine cooling system. Refer to MA-12, "DRAINING ENGINE COOLANT" .
2. Remove the rear RH interior trim panel. Refer to EI-34, "
Removal and Installation" .
3. Disconnect the rear heater hoses from the heater core.
4. Remove the rear heater core bracket.
5. Remove the heater core.
Installation
Installation is in the reverse order of removal.
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Removal and Installation for CompressorEJS002DJ
A/C Compressor Mounting
REMOVAL
1. Discharge the refrigerant. Refer to ATC-162, "HFC-134a (R-134a) Service Procedure" .
2. Remove the front right wheel and tire assembly. Refer to WT-6, "
Rotation" .
3. Remove the engine under cover and the splash shield using power tool.
4. Remove the engine air cleaner and air ducts. Refer to EM-14, "
REMOVAL" .
5. Remove the drive belt. Refer to EM-12, "
Removal" .
6. Disconnect the compressor electrical connector.
7. Disconnect the high-pressure flexible hose and low-pressure flexible hose from the compressor.
CAUTION:
Cap or wrap the joint of the hose with suitable material such as vinyl tape to avoid the entry of
contaminants.
8. Remove the compressor bolts and nut using power tools.
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2. Install the magnet coil harness clip using a screwdriver.
3. Install the pulley assembly using Tool and a wrench, then install
the snap ring using snap ring pliers.
4. Install the clutch disc on the compressor shaft, together with the
original shim(s). Press the clutch disc down by hand.
5. Install the clutch pulley bolt using Tool, to prevent the clutch disc
from turning and tighten the bolt to specification. Refer to AT C -
164, "Components" .
CAUTION:
After tightening the clutch pulley bolt, check that the clutch
pulley rotates smoothly.
6. Check the pulley clearance all the way around the clutch disc as
shown.
7. If the specified clearance is not obtained, replace the adjusting
spacer to readjust.
8. Connect the compressor electrical connector.
9. Install the drive belt. Refer to EM-13, "
Installation" .
10. Install the engine under cover and the splash shield.Tool number : — (J-38873-A)
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WHA184
Tool number : J-44614
WHA229
Clutch disc-to-pulley clearance : 0.3 - 0.6 mm
(0.012 - 0.024 in)
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BREAK-IN OPERATION
When replacing compressor clutch assembly, always conduct the break-in operation. This is done by engag-
ing and disengaging the clutch about 30 times. Break-in operation raises the level of transmitted torque.
Removal and Installation for Low-pressure Flexible HoseEJS002DL
REMOVAL
1. Remove the engine room cover using power tools.
2. Remove the engine air cleaner and air ducts. Refer to EM-14, "
REMOVAL" .
3. Remove the cowl top extension. Refer to EI-18, "
COWL TOP" .
4. Discharge the refrigerant. Refer to ATC-162, "
HFC-134a (R-134a) Service Procedure" .
CAUTION:
Cap or wrap the joint of the pipe with suitable material such as vinyl tape to avoid the entry of con-
taminants.
5. Remove the low-pressure flexible hose. Refer to ATC-164, "
Components" .
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-164, "
Components" .
CAUTION:

Replace the O-ring of the low-pressure flexible hose with a new one, then apply compressor oil to
it when installing it.

After charging refrigerant, check for leaks.
Removal and Installation for High-pressure Flexible HoseEJS002DM
REMOVAL
1. Remove the engine under cover.
2. Remove the engine air cleaner and air ducts. Refer to EM-14, "
REMOVAL" .
3. Discharge the refrigerant. Refer to ATC-162, "
HFC-134a (R-134a) Service Procedure" .
4. Remove the high-pressure flexible hose. Refer to ATC-164, "
Components" .
CAUTION:
Cap or wrap the joint of the hose with suitable material such as vinyl tape to avoid the entry of
contaminants.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-164, "
Components" .
CAUTION:

Replace the O-ring of the high-pressure flexible hose with a new one, then apply compressor oil to
it when installing it.

After charging refrigerant, check for leaks.
Removal and Installation for High-pressure PipeEJ S00 2DN
REMOVAL
1. Remove the cowl top extension. Refer to EI-18, "COWL TOP" .
2. Disconnect the battery negative cable.
3. Reposition the IPDM E/R aside.
4. Remove the front right wheel and tire assembly. Refer to WT-6, "
Rotation" .
5. Position aside the front floor insulator.
6. Discharge the refrigerant. Refer to ATC-162, "
HFC-134a (R-134a) Service Procedure" .
7. Remove the low pressure pipe. Refer to ATC-171, "
Removal and Installation for Low-pressure Pipe" .
8. Remove the high-pressure pipe. Refer to ATC-164, "
Components" .
CAUTION:
Cap or wrap the joint of the pipe with suitable material such as vinyl tape to avoid the entry of con-
taminants.

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INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-164, "
Components" .
CAUTION:

Replace the O-ring of the high-pressure pipe with a new one, then apply compressor oil to it when
installing it.

After charging refrigerant, check for leaks.
Removal and Installation for Low-pressure PipeEJ S00 2DO
REMOVAL
1. Discharge the refrigerant. Refer to ATC-162, "HFC-134a (R-134a) Service Procedure" .
2. Remove the cowl top and the cowl top extension. Refer to EI-18, "
COWL TOP" .
3. Remove the low-pressure pipe. Refer to ATC-164, "
Components" .
CAUTION:
Cap or wrap the joint of the pipes with suitable material such as vinyl tape to avoid the entry of
contaminants.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-164, "
Components" .
CAUTION:

Replace the O-ring of the high/low-pressure pipe with a new one, then apply compressor oil to it
when installing it.

After charging refrigerant, check for leaks.
Removal and Installation for Rear High- and Low-pressure A/C and Heater Core
Pipes
EJS0060M
REMOVAL
1. Discharge the refrigerant. Refer to ATC-162, "HFC-134a (R-134a) Service Procedure" .
2. Drain the coolant from the engine cooling system. Refer to CO-8, "
Changing Engine Coolant" .
3. Disconnect the underfloor rear heater hoses (1 and 2) from the
rear heater pipes underneath the vehicle.

⇐: Front
4. Remove the rear high- and low-pressure pipes bolt (A) to dis-
connect the rear high- and low-pressure pipes from the under-
floor rear high- and low-pressure pipes underneath the vehicle.
CAUTION:
Cap or wrap the joint of the pipes with suitable material
such as vinyl tape to avoid the entry of air.
5. Remove the rear high- and low-pressure pipes nuts (B) under-
neath the vehicle.
NOTE:
The remaining steps are performed inside the rear luggage area of the vehicle.
6. Remove the luggage side finisher lower RH. Refer to EI-39, "
LUGGAGE FLOOR TRIM" .
7. Disconnect the rear heater core hoses (1 and 2) from the rear
heater core (3).

⇐: Front
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8. Remove the rear high- and low-pressure pipes bracket bolt (A)
to release the bracket.

Rear blower motor (1)

⇐: Front
9. Remove the rear high- and low-pressure pipes bolt (A) to dis-
connect the rear high- and low-pressure pipes from the rear
expansion valve (1).

⇐: Front
CAUTION:
Cap or wrap the joint of the pipes with suitable material
such as vinyl tape to avoid the entry of air.
10. Disconnect the following electrical connectors:

Rear air mix door motor (1)

Rear blower motor resistor (2)

Rear blower motor (3)

⇐: Front
11. Disconnect the ducts from the rear heater and cooling unit assembly. Refer to ATC-157, "
Components" .
12. Remove the rear heater and cooling unit assembly.
CAUTION:
Cap or wrap the joint of the pipes with suitable material such as vinyl tape to avoid the entry of air.
13. Remove the rear high- and low-pressure A/C pipes.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-164, "
Components" .
CAUTION:

Replace the O-ring of the high/low-pressure pipe with a new one, then apply compressor oil to it
when installing it.

After charging refrigerant, check for leaks.
Removal and Installation for Underfloor Rear High- and Low-pressure A/C and
Heater Core Pipes
EJS0060N
REMOVAL
1. Drain the coolant from the engine cooling system. Refer to CO-8, "Changing Engine Coolant" .
2. Disconnect the battery negative terminal.
3. Disconnect the generator harness.
4. Discharge the refrigerant. Refer to ATC-162, "
HFC-134a (R-134a) Service Procedure" .
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2. Pour one bottle 7.4 cc (1/4 ounce) of the HFC-134a (R-134a) fluorescent leak detection dye (J-41447) into
the HFC-134a (R-134a) dye injector (J-41459).
CAUTION:
If repairing the A/C system or replacing a component, pour the HFC-134a (R-134a) fluorescent leak
detection dye (J-41447) directly into the open system connection and proceed with the service
procedures.
3. Connect the refrigerant dye injector (J-41459) to the low-pressure service valve.
4. Start the engine and switch the A/C system ON.
5. When the A/C system is operating (compressor running), inject one bottle 7.4 cc (1/4 ounce) of HFC-134a
(R-134a) fluorescent leak detection dye (J-41447) through the low-pressure service valve using HFC-
134a (R-134a) dye injector (J-41459). Refer to the manufacturer's operating instructions.
6. With the engine still running, disconnect the HFC-134a (R-134a) dye injector (J-41459) from the low-pres-
sure service valve.
7. Operate the A/C system for a minimum of 20 minutes to mix the HFC-134a (R-134a) fluorescent leak
detection dye (J-41447) with the A/C system oil. Depending on the leak size, operating conditions and
location of the leak, it may take from minutes to days for the HFC-134a (R-134a) fluorescent leak detec-
tion dye to penetrate an A/C system leak and become visible.
Electronic Refrigerant Leak DetectorEJS002DY
PRECAUTIONS FOR HANDLING LEAK DETECTOR
NOTE:
When performing a refrigerant leak check, use a electronic refrigerant leak detector (J-41995) or equivalent.
Ensure that the electronic refrigerant leak detector (J-41995) is calibrated and set properly according to the
manufacturer's operating instructions.
The electronic refrigerant leak detector (J-41995) is a delicate
device. To use the leak detector properly, read the manufacturer's
operating instructions and perform any specified maintenance.
1. Position the probe approximately 5 mm (3/16 in) away from the
point to be checked as shown.
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2. When checking for leaks, circle each fitting completely with the
probe as shown.
3. Move the probe along each component at a speed of approxi-
mately 25 - 50 mm (1 - 2 in)/second as shown.
CHECKING PROCEDURE
NOTE:
To prevent inaccurate or false readings, make sure there is no refrigerant vapor, shop chemicals, or cigarette
smoke in the vicinity of the vehicle. Perform the leak test in a calm area (low air/wind movement) so that the
leaking refrigerant is not dispersed.
1. Turn the engine OFF.
2. Connect the manifold gauge set (J-39183-C) to the A/C service ports. Refer to ATC-162, "
SETTING OF
SERVICE TOOLS AND EQUIPMENT" .
3. Check if the A/C refrigerant pressure is at least 345 kPa (3.52 kg/cm
2 , 50 psi) above a temperature of
16°C (61°F). If less than specification, recover/evacuate and recharge the system with the specified
amount of refrigerant. Refer to ATC-162, "
HFC-134a (R-134a) Service Procedure" .
NOTE:
At temperatures below 16°C (61°F), leaks may not be detected since the system may not reach 345 kPa
(3.52 kg/cm
2 , 50 psi) pressure.
4. Perform the leak test from the high-pressure side (front A/C compressor discharge “a” to evaporator inlet
“f”, or rear piping connection “l”) to the low-pressure side (front A/C evaporator drain hose “g” to shaft seal
“k”, and rear A/C evaporator drain hose “o” to piping connection “r”). Refer to ATC-164, "
Components" .
Clean the component to be checked and carefully move the electronic refrigerant leak detector probe
completely around the following connections and components.

Compressor

Check the high and low-pressure pipe and hose fittings, relief valve, and compressor shaft seal

Check the liquid tank

Check the refrigerant pressure sensor

Check all around the service valves. Check that the service valve caps are tightly screwed on to the
service valves (to prevent leaks).
NOTE:
After removing manifold gauge set (J-39183-C) from the service valves, wipe any residue from the ser-
vice valves to prevent any false readings by the electronic refrigerant leak detector (J-41995).

Evaporator
With engine OFF, turn blower fan on “High” for at least 15 seconds to dissipate any refrigerant trace in
the heater and cooling unit assembly. Wait a minimum of 10 minutes accumulation time (refer to the
manufacturer's recommended procedure for actual wait time) before inserting the electronic refrigerant
leak detector probe into the heater and cooling unit assembly drain hose.
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