INFINITI QX56 2008 Factory Service Manual

HA-16
< PREPARATION >
PREPARATION
Commercial Service Tool
INFOID:0000000001516640
—
(J-39699)
Refrigerant weight scale For measuring of refrigerant
Fitting size-Thread size
• 1/2”-16 ACME
—
(J-39649)
Vacuum pump
(Including the isolator valve) Capacity:
• Air displacement: 4 CFM
• Micron rating: 20 microns
• Oil capacity: 482 g (17 oz)
Fitting size-Thread size
• 1/2”-16 ACME
Tool number
(Kent-Moore No.)
Tool name
Description
S-NT200
S-NT203
Tool name
Description
(J-41810-NI)
Refrigerant identifier equipment (R-
134a) For checking refrigerant purity and
system contamination
Power tool Loosening bolts and nuts
RJIA0197E
PBIC0190E
Revision: March 2010 2008 QX56

REFRIGERATION SYSTEMHA-17
< FUNCTION DIAGNOSIS >
C
DE
F
G H
J
K L
M A
B
HA
N
O P
FUNCTION DIAGNOSIS
REFRIGERATION SYSTEM
Refrigerant CycleINFOID:0000000001516641
REFRIGERANT FLOW
The refrigerant flows in the standard pattern, that is, through the compressor, the condenser with liquid tank,
through the front and rear evaporators, and back to the compressor. The refrigerant evaporation through the
evaporator coils are controlled by front and rear externally equalized expansion valves, located inside the front
and rear evaporator cases.
Refrigerant System ProtectionINFOID:0000000001516642
REFRIGERANT PRESSURE SENSOR
The refrigerant system is protected against excessively hi gh or low pressures by the refrigerant pressure sen-
sor, located on the condenser. If the system pressure rises above or falls below the specifications, the refriger-
ant pressure sensor detects the pressure inside the refrigerant line and sends a voltage signal to the ECM.
The ECM de-energizes the A/C relay to disengage the magnetic compressor clutch when pressure on the high
pressure side detected by refrigerant pressu re sensor is over about 2,746 kPa (28 kg/cm
2, 398 psi), or below
about 120 kPa (1.22 kg/cm
2, 17.4 psi).
PRESSURE RELIEF VALVE
The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.
When the pressure of refrigerant in the system incr eases to an abnormal level [more than 2,990 kPa (30.5 kg/
Revision: March 2010 2008 QX56

HA-18
< FUNCTION DIAGNOSIS >
REFRIGERATION SYSTEM
cm2, 433.6 psi)], the release port on the pressure relief valve automatically opens and releases refrigerant into
the atmosphere.
WJIA1342E
Revision: March 2010 2008 QX56

OIL
HA-19
< FUNCTION DIAGNOSIS >
C
D E
F
G H
J
K L
M A
B
HA
N
O P
OIL
Maintenance of Oil in CompressorINFOID:0000000001516643
The oil in the compressor circulates through the system with the refrigerant. Add oil to compressor when
replacing any component or after a large refrigerant leakage has occurred. It is important to maintain the spec-
ified amount.
If oil quantity is not maintained properly , the following malfunctions may result:
• Lack of oil: May lead to a seized compressor
• Excessive oil: Inadequate cooling (thermal exchange interference)
Revision: March 2010 2008 QX56

HA-20
< ON-VEHICLE MAINTENANCE >
REFRIGERATION SYSTEM
ON-VEHICLE MAINTENANCE
REFRIGERATION SYSTEM
HFC-134a (R-134a) Service ProcedureINFOID:0000000001516644
SETTING OF SERVICE TOOLS AND EQUIPMENT
Discharging Refrigerant
WARNING:
Avoid breathing A/C refrigerant and oil vapor or mist. Exposure may irritate eyes, nose and throat.
Remove HFC-134a (R-134a) refrigerant from the A/C system using certified service equipment meeting
requirements of SAE J2210 HFC-134a (R-134a) recycling equipment or SAE J2201 HFC-134a (R-134a)
recovery equipment. If an accident al system discharge occurs, ventilate the work area before resum-
ing service. Additional health and safety information may be obtained from the refrigerant and oil man-
ufacturers.
Evacuating System and Charging Refrigerant
1. Shut-off valve 2. A/C service valve 3. Recovery/recycling equipment
WJIA0579E
WJIA0580E
Revision: March 2010 2008 QX56

REFRIGERATION SYSTEMHA-21
< ON-VEHICLE MAINTENANCE >
C
DE
F
G H
J
K L
M A
B
HA
N
O P
1. Shut-off valve 2. A/C service valve3. Recovery/recycling equipment
4. Refrigerant container (HFC-134a) 5. Weight scale (J-39650) 6. Evacuating vacuum pump (J-39699)
7. Manifold gauge set (J-39183)
*1 HA-22, "
Maintenance of Oil Quantity
in Compressor"
*3HAC-113, "Performance Chart"*5 HA-4, "Contaminated Refrigerant"
*2HAC-109, "Component Function
Check"
*4HAC-110, "Diagnostic Work Flow"
WJIA1923E
Revision: March 2010 2008 QX56

HA-22
< ON-VEHICLE MAINTENANCE >
OIL
OIL
Maintenance of Oil Quantity in CompressorINFOID:0000000001516645
The oil in the compressor circulates through the system with the refrigerant. Add oil to compressor when
replacing any component or after a large refrigerant leakage has occurred. It is important to maintain the spec-
ified amount.
If oil quantity is not maintained properly, the following malfunctions may result:
• Lack of oil: May lead to a seized compressor
• Excessive oil: Inadequate cooling (thermal exchange interference)
OIL
Name: NISSAN A/C System Oil Type S or equivalent
CHECKING AND ADJUSTING
CAUTION:
If excessive oil leakage is noted, do not perform the oil return operation.
Start the engine and set the following conditions:
Test Condition
• Engine speed: Idling to 1,200 rpm
• A/C switch: On
• Blower fan speed: MAX position
• Temp. control: Optional [Set so that intake air temperature is 25 ° to 30 ° C (77 ° to 86 °F)]
• Intake position: Recirculation ( )
• Perform oil return operation for about ten minutes
Adjust the oil quantity according to the following table.
Oil Adjusting Procedure for Components Replacement Except Compressor
After replacing any of the following major components, add the correct amount of oil to the system.
Amount of Oil to be Added
• *1: If refrigerant leak is small, no addition of oil is needed.
Oil Adjustment Procedure for Compressor Replacement
Part replaced Oil to be added to system
Remarks
Amount of oil
m (US fl oz, Imp fl oz)
Front evaporator 75 (2.5, 2.6)—
Rear evaporator 75 (2.5, 2.6)—
Condenser 75 (2.5, 2.6)—
Liquid tank 5 (0.2, 0.2)Add if compressor is not replaced.
In case of refrigerant leak 30 (1.0, 1.1)
Large leak
— Small leak *1
Revision: March 2010 2008 QX56

OIL
HA-23
< ON-VEHICLE MAINTENANCE >
C
D E
F
G H
J
K L
M A
B
HA
N
O P
1. Before connecting recovery/recycling equipment to vehicle, check recovery/recycling equipment gauges.
No refrigerant pressure should be displayed. If NG, recover refrigerant from equipment lines.
2. Connect recovery/recycling equipment to vehicle. Confir m refrigerant purity in supply tank using recovery/
recycling equipment and refrigerant identifier. If NG, refer to HA-4, "
Contaminated Refrigerant".
3. Confirm refrigerant purity in vehicle A/C system using recovery/recycling equipment and refrigerant identi-
fier. If NG, refer to HA-4, "
Contaminated Refrigerant".
4. Discharge refrigerant into the refrigerant recove ry/recycling equipment. Measure oil discharged into the
recovery/recycling equipment.
5. Drain the oil from the “old” (removed) compress or into a graduated container and recover the amount of
oil drained.
6. Drain the oil from the “new” compressor into a separate, clean container.
7. Measure an amount of new oil installed equal to am ount drained from “old” compressor. Add this oil to
“new” compressor through the suction port opening.
8. Measure an amount of new oil equal to the amount recovered during discharging. Add this oil to “new” compressor through the suction port opening.
9. If the liquid tank also needs to be replaced, add an additional 5 m (0.2 US fl oz, 0.2 Imp fl oz) of oil at this time.
CAUTION:
Do not add this 5 m (0.2 US fl oz, 0.2 Imp fl oz) of oil if only replacing the compressor.
1. New compressor2. Old compressor3. Recovery/recycling equipment
4. Measuring cup X 5. Measuring cup Y6. New oil
A. Drain oil from the new compressor into clean container B. Record amount of oil recovered C.
Add an additional 5 m (0.2 US fl oz,
0.2 Imp fl oz) of new oil when replacing
liquid tank
D. Install new oil equal to recorded amounts in measuring cups X plus Y
WJIA1716E
Revision: March 2010 2008 QX56

HA-24
< ON-VEHICLE MAINTENANCE >
FLUORESCENT LEAK DETECTOR
FLUORESCENT LEAK DETECTOR
Checking of Refrigerant LeaksINFOID:0000000001516646
PRELIMINARY CHECK
Perform a visual inspection of all refrigeration parts, fittings, hoses and components for signs of A/C oil leak-
age, damage, and corrosion. Any A/C oil leakage may indicate an area of refrigerant leakage. Allow extra
inspection time in these areas when using either an el ectronic refrigerant leak detector (J-41995) or fluores-
cent dye leak detector (J-42220).
If any dye is observed using a fluorescent dye leak detector (J-42220), confirm the leak using a electronic
refrigerant leak detector (J-41995). It is possible that the dye is from a prior leak that was repaired and not
properly cleaned.
When searching for leaks, do not stop when one leak is found but continue to check for additional leaks at all
system components and connections.
When searching for refrigerant leaks using an electronic refrigerant leak detector (J-41995), move the probe
along the suspected leak area at 25 - 50 mm (1 - 2 in) per second and no further than 6 mm (1/4 in) from the
component.
CAUTION:
Moving the electronic refrigerant l eak detector probe slower and closer to the suspected leak area will
improve the chances of finding a leak.
Checking System for L eaks Using the Fluorescent Dye Leak DetectorINFOID:0000000001516647
1. Check the A/C system for leaks using the fluorescent dye leak detector and safety goggles (J-42220) in a
low sunlight area (area without windows preferable). Il luminate all components, fittings and lines. The dye
will appear as a bright green/yellow area at the point of leakage. Fluorescent dye observed at the evapo-
rator drain opening indicates an evaporator core asse mbly leak (tubes, core or expansion valve).
2. If the suspected area is difficult to see, use an adjustable mirror or wipe the area with a clean shop rag or cloth, then inspect the shop rag or cloth with the fl uorescent dye leak detector (J-42220) for dye residue.
3. After the leak is repaired, remove any residual dye using refrigerant dye cleaner (J-43872) to prevent
future misdiagnosis.
4. Perform a system performance check and then verify t he leak repair using a electronic refrigerant leak
detector (J-41995).
NOTE:
• Other gases in the work area or substances on the A/C components, for example, anti-freeze, wind-
shield washer fluid, solvents and oils, may falsely tri gger the leak detector. Make sure the surfaces to be
checked are clean.
• Clean with a dry cloth or blow off with shop air.
• Do not allow the sensor tip of the electronic refri gerant leak detector (J-41995) to contact with any sub-
stance. This can also cause false readings and may damage the detector.
Dye InjectionINFOID:0000000001516648
NOTE:
This procedure is only necessary when recharging the system or when the compressor has seized and must
be replaced.
1. Check the A/C system static (at rest) pressure . Pressure must be at least 345 kPa (3.52 kg/cm
2 , 50 psi).
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 co mponent, 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.
Revision: March 2010 2008 QX56

FLUORESCENT LEAK DETECTORHA-25
< ON-VEHICLE MAINTENANCE >
C
DE
F
G H
J
K L
M A
B
HA
N
O P
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 minut es 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.
Revision: March 2010 2008 QX56