2007 INFINITI QX56 cooling

ATC-164
< SERVICE INFORMATION >
REFRIGERANT LINES
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 hi gh-pressure pipe with new ones.
Apply compressor oil to the O- rings when installing them.
Removal and Installation for Rear EvaporatorINFOID:0000000003533304
Rear Heater and Cooling Unit Assembly
REMOVAL
1. Remove the rear heater and cooling unit assembly from the vehicle. Refer\
to ATC-133, "Removal and
Installation".
2. Remove the rear blower motor.
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 LINESATC-165
< SERVICE INFORMATION >
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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 -
148, "Removal and Installation".
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 ne w ones. Apply compressor oil to the O-rings when
installing them.
• After charging refrigerant, check for leaks.
Removal and Installation for Front Expansion ValveINFOID:0000000003533305
REMOVAL
1. Discharge the refrigerant. Refer to ATC-150, "HFC-134a (R-134a) Service Procedure".
2. Remove the front evaporator. Refer to ATC-163, "
Removal and Installation for Front Evaporator".
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 re frigerant 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 ValveINFOID:0000000003533306
REMOVAL
1. Discharge the refrigerant. Refer to ATC-150, "HFC-134a (R-134a) Service Procedure".
2. Remove the luggage side lower finisher RH. Refer to EI-39
.
3. Disconnect the A/C refrigerant pi pes from the expansion valve.
CAUTION:
Cap or wrap the A/C refrigerant pipe ends with a suitable material such as vinyl tape to avoid the
entry of air and contaminants.
4. Remove 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-152, "
Component".

ATC-168
< SERVICE INFORMATION >
REFRIGERANT LINES
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 t here 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-150, "
HFC-134a (R-
134a) Service Procedure".
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/evacuat e and recharge the system with the specified
amount of refrigerant. Refer to ATC-150, "
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-152, "
Component".
Clean the component to be checked and carefully move the electronic refrigerant leak detector probe
completely around the following connections and components.
• Check the compressor shaft seal
• 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 screwed tightly on the ser-
vice 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 l east 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.
NOTE:
Keep the probe inserted for at least 10 seconds. Use c aution not to contaminate the probe tip with water
or dirt that may be in the drain hose.
5. If a leak is detected, verify at least once by blow ing compressed air into the area of the suspected leak,
then repeat the leak check.
6. Do not stop when one leak is found. Continue to c heck for additional leaks at all system components and
connections.
7. If no leaks are found, perform steps 8 - 11.
8. Start the engine.
9. Set the heater A/C controls as follows: NOTE:
For the automatic system, turn OF F the automatic controls and set the heater A/C controls manually.
a. A/C switch to ON
SHA708EA

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CONTENTS
ENGINE COOLING SYSTEM
SERVICE INFORMATION ............................2
PRECAUTIONS ...................................................2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ...................................................................
2
Precaution for Liquid Gasket .....................................2
PREPARATION ...................................................4
Special Service Tool .................................................4
Commercial Service Tool ..........................................4
OVERHEATING CAUSE ANALYSIS ..................6
Troubleshooting Chart ...............................................6
COOLING SYSTEM ............................................8
Cooling Circuit ...........................................................8
Schematic .................................................................8
ENGINE COOLANT ............................................9
Inspection ..................................................................9
Changing Engine Coolant .........................................9
RADIATOR ........................................................13
Removal and Installation .........................................13
Checking Radiator ...................................................15
ENGINE COOLING FAN ...................................16
Removal and Installation (Crankshaft Driven
Type) .......................................................................
16
Removal and Installation (Motor Driven Type) ........17
WATER PUMP ..................................................18
Removal and Installation .........................................18
THERMOSTAT AND WATER PIPING ..............20
Removal and Installation .........................................20
SERVICE DATA AND SPECIFICATIONS
(SDS) .................................................................
22
Standard and Limit ..................................................22

CO-4
< SERVICE INFORMATION >
PREPARATION
PREPARATION
Special Service ToolINFOID:0000000003531564
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolINFOID:0000000003531565
Tool number
(Kent-Moore No.)
Tool nameDescription
K V 1 0 1111 0 0
(J-37228)
Seal cutterRemoving steel oil pan and rear timing chain
case
WS39930000
(—)
Tube pressurePressing the tube of liquid gasket
EG17650301
(J-33984-A)
Radiator cap tester adapterAdapting radiator cap tester to radiator cap
and radiator filler neck
a: 28 (1.10) dia.
b: 31.4 (1.236) dia.
c: 41.3 (1.626) dia.
Unit: mm (in)
KV991J0070
(J-45695)
Coolant refill toolFor refilling engine cooling system
KV991J0010
(J-23688)
Engine coolant refractometerChecking concentration of ethylene glycol in
engine coolant
NT046
S-NT052
S-NT564
LMA053
WBIA0539E

CO-6
< SERVICE INFORMATION >
OVERHEATING CAUSE ANALYSIS
OVERHEATING CAUSE ANALYSIS
Troubleshooting ChartINFOID:0000000003531566
Symptom Check items
Cooling sys-
tem parts
malfunctionPoor heat transferWater pump malfunction Worn or loose drive belt
— Thermostat stuck closed —
Damaged finsDust contamination or pa-
per clogging
Physical damage
Clogged radiator cooling
tubeExcess foreign material
(rust, dirt, sand, etc.)
Water cut valve malfunctionExcess foreign material
(rust, dirt, sand, etc.), phys-
ical damage
Reduced air flowCooling fan does not oper-
ate
Fan assembly — High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud — — —
Improper engine coolant
mixture ratio———
Poor engine coolant quality — Engine coolant density —
Insufficient engine coolantEngine coolant leaksCooling hoseLoose clamp
Cracked hose
Water pump Poor sealing
Radiator capLoose
Poor sealing
RadiatorO-ring for damage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tankExhaust gas leaks into cool-
ing systemCylinder head deterioration
Cylinder head gasket deteri-
oration

CO-8
< SERVICE INFORMATION >
COOLING SYSTEM
COOLING SYSTEM
Cooling CircuitINFOID:0000000003531567
SchematicINFOID:0000000003531568
WBIA0404E
WBIA0463E

ENGINE COOLANT
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ENGINE COOLANT
InspectionINFOID:0000000003531569
LEVEL CHECK
• Check if the engine coolant reservoir tank level is within MIN to
MAX level when engine is cool.
• Adjust engine coolant level as necessary.
CHECKING COOLING SYSTEM FOR LEAKS
WARNING:
Never remove the radiator or reservoir cap when the engine is hot. Serious burns could occur from
high-pressure engine coolant escaping from the radiator or reservoir.
• To check for leakage, apply pressure to the cooling system at the
reservoir filler neck using suitable tool and Tool.
CAUTION:
Higher pressure than specified may cause radiator damage.
NOTE:
In case that engine coolant decreases, replenish cooling system
with engine coolant.
• If any concerns are found, repair or replace damaged parts.
CHECKING RESERVOIR CAP
• Check reservoir cap relief pressure using suitable tool and Tool.
NOTE:
Apply engine coolant to the cap seal.
• Replace the reservoir cap if there is any damage in the negative-
pressure valve, or if the open-valve pressure is outside of the limit.
CHECKING RADIATOR CAP
Inspect the radiator cap.
NOTE:
Thoroughly wipe out the radiator filler neck to remove any waxy residue or foreign material.
• Replace the cap if the metal plunger cannot be seen around the edge of the black rubber gasket.
• Replace the cap if deposits of waxy residue or other foreign material are on the black rubber gasket or the
metal retainer.
Changing Engine CoolantINFOID:0000000003531570
WARNING:
• To avoid being scalded, never change the coolant when the engine is hot.
SMA412B
Tool number : EG17650301 (J-33984-A)
Leakage test pressure : 137 kPa (1.4 kg/cm, 20 psi)
WBIA0612E
Tool number : EG17650301 (J-33984-A)
Standard
: 95 - 125 kPa (0.97 - 1.28 kg/cm
2, 14 - 18 psi)
WBIA0611E