cooling INFINITI QX56 2004 Factory Workshop Manual

DUCTS AND GRILLES
ATC-157
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Revision: August 20072004 QX56
DUCTS AND GRILLESPFP:27860
ComponentsEJS002DF
Ducts - Front Heater and Cooling Unit Assembly
WJIA0956E

ATC-158
DUCTS AND GRILLES
Revision: August 20072004 QX56
Ducts - Rear Heater and Cooling Unit Assembly
1. Defroster nozzle 2. LH side demister duct 3. LH ventilator duct
4. RH side demister duct 5. RH ventilator duct 6. Center ventilator duct
7. Front heater and cooling unit assembly 8. Floor duct 9. Clips
10. Heat duct
LJIA0142E
1. Rear floor duct 2. Rear heater and cooling unit assembly 3. Rear lower overhead duct
4. Rear upper overhead duct

REFRIGERANT LINES
ATC-165
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Revision: August 20072004 QX56
Rear A/C
NOTE:
Refer to AT C - 7 , "
Precautions for Refrigerant Connection" .
1. High-pressure service valve 2. Grommet 3. High-pressure pipe
4. Refrigerant pressure sensor 5. Condenser 6. Compressor shaft seal
7. High-pressure flexible hose 8. Low-pressure flexible hose 9. Low-pressure service valve
10. Low-pressure pipe 11. Expansion valve (front) 12. Drain hose
WJIA2315E
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.

REFRIGERANT LINES
ATC-171
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Revision: August 20072004 QX56
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
WJIA2310E
WJIA2311E

ATC-172
REFRIGERANT LINES
Revision: August 20072004 QX56
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" .
WJIA2312E
WJIA2313E
WJIA2314E

REFRIGERANT LINES
ATC-175
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Revision: August 20072004 QX56
Removal and Installation for Front EvaporatorEJS002DR
Front Heater and Cooling Unit Assembly
REMOVAL
1. Remove the front heater core. Refer to ATC-148, "FRONT HEATER CORE" .
LJIA0138E
1. Heater core cover 2. Heater core pipe bracket 3. Heater core
4. Upper bracket 5. Upper heater and cooling unit case 6. A/C evaporator
7. Lower heater and cooling unit case 8. Blower motor 9. Variable blower control

ATC-176
REFRIGERANT LINES
Revision: August 20072004 QX56
2. Remove the defroster mode door arm.
3. Separate the heater core and cooling unit case.
4. Remove the evaporator.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Replace the O-rings on the low-pressure flexible hose and the high-pressure pipe with new ones.
Apply compressor oil to the O-rings before installing them.
Removal and Installation for Rear EvaporatorEJS002DS
Rear Heater and Cooling Unit Assembly
LJIA0135E
1. Front cover 2. Evaporator and heater core case 3. Evaporator
4. Side cover 5. Heater core 6. Rear blower motor
7. Blower motor case 8. Rear blower motor resistor

REFRIGERANT LINES
ATC-177
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Revision: August 20072004 QX56
REMOVAL
1. Remove the rear heater and cooling unit assembly from the vehicle. Refer to ATC-146, "REAR HEATER
AND COOLING UNIT ASSEMBLY" .
2. Remove the rear blower motor.
3. Remove the rear blower speed resistor.
4. Remove the rear air mix door motor.
5. Remove the rear duct and blend door assembly. Refer to AT C -
160, "DEFROSTER NOZZLE" .
6. Disassemble the rear heater and cooling unit assembly to
remove the evaporator.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:

Replace the O-rings on the rear A/C pipes with new ones. Apply compressor oil to the O-rings
before installing them.

After charging refrigerant, check for leaks.
Removal and Installation for Front Expansion ValveEJS002DT
REMOVAL
1. Discharge the refrigerant. Refer to ATC-162, "HFC-134a (R-134a) Service Procedure" .
2. Remove the front heater and cooling unit assembly. Refer to ATC-145, "
FRONT HEATER AND COOLING
UNIT ASSEMBLY" .
3. Remove the cooler grommet.
4. Remove the expansion valve.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:

Replace the O-rings on the A/C refrigerant pipes with new ones, then apply compressor oil to them
when installing them.

After charging refrigerant, check for leaks.
Removal and Installation for Rear Expansion ValveEJS002DU
REMOVAL
1. Discharge the refrigerant. Refer to ATC-162, "HFC-134a (R-134a) Service Procedure" .
2. Remove the rear RH interior side trim panel. Refer to EI-34, "
Removal and Installation" .
3. Disconnect the A/C refrigerant pipes from the expansion valve.
LJIA0021E
WJIA0582E
Expansion valve bolts : 4 N·m (0.41 kg-m, 35 in-lb)
A/C refrigerant pipe to expansion valve bolt : Refer to ATC-164, "
Compo-
nents" .

ATC-180
REFRIGERANT LINES
Revision: August 20072004 QX56
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.
SHA7 06 E
SHA708EA

CO-1
ENGINE COOLING SYSTEM
B ENGINE
CONTENTS
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SECTION CO
A
CO
Revision: August 20072004 QX56 PRECAUTIONS .......................................................... 2
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 2
PREPARATION ........................................................... 3
Special Service Tools ............................................... 3
Commercial Service Tools ........................................ 3
OVERHEATING CAUSE ANALYSIS .......................... 4
Troubleshooting Chart .............................................. 4
COOLING SYSTEM .................................................... 6
Cooling Circuit .......................................................... 6
System Drawing ....................................................... 7
ENGINE COOLANT .................................................... 8
Inspection ................................................................. 8
LEVEL CHECK ..................................................... 8
CHECKING COOLING SYSTEM FOR LEAKS ..... 8
CHECKING RESERVOIR CAP ............................. 8
CHECKING RADIATOR CAP ................................ 8
Changing Engine Coolant ........................................ 8
DRAINING ENGINE COOLANT ........................... 8
REFILLING ENGINE COOLANT .......................... 9
FLUSHING COOLING SYSTEM ........................... 9
RADIATOR ................................................................ 10
Removal and Installation ........................................ 10
REMOVAL ........................................................... 10
INSTALLATION ................................................... 12
INSPECTION AFTER INSTALLATION ............... 12
Checking Radiator .................................................. 12ENGINE COOLING FAN ........................................... 13
Removal and Installation (Crankshaft Driven Type) ... 13
REMOVAL ........................................................... 13
INSPECTION AFTER REMOVAL ....................... 13
INSTALLATION ................................................... 13
INSPECTION AFTER INSTALLATION ................ 13
Removal and Installation (Motor Driven Type) ....... 14
REMOVAL ........................................................... 14
INSTALLATION ................................................... 14
WATER PUMP .......................................................... 15
Removal and Installation ........................................ 15
REMOVAL ........................................................... 15
INSPECTION AFTER REMOVAL ....................... 15
INSTALLATION ................................................... 15
INSPECTION AFTER INSTALLATION ................ 16
THERMOSTAT AND WATER PIPING ...................... 17
Removal and Installation ........................................ 17
REMOVAL ........................................................... 17
INSPECTION AFTER REMOVAL ....................... 18
INSTALLATION ................................................... 18
INSPECTION AFTER INSTALLATION ................ 18
SERVICE DATA AND SPECIFICATIONS (SDS) ...... 19
Standard and Limit .................................................. 19
ENGINE COOLANT CAPACITY (APPROXI-
MATE) .................................................................. 19
THERMOSTAT .................................................... 19
RADIATOR .......................................................... 19