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Nissan Pathfinder (2010 year). Manual - part 436

HA-22

< FUNCTION DIAGNOSIS >

REFRIGERATION SYSTEM

Refrigerant Cycle

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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.

FREEZE PROTECTION

The compressor cycles on and off to maintain the evaporator temperature within a specified range. When the

evaporator coil temperature falls below a specified point, the intake sensor interrupts the compressor opera-

tion. When the evaporator coil temperature rises above the specification, the intake sensor allows compressor

operation.

Refrigerant System Protection

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REFRIGERANT PRESSURE SENSOR

The refrigerant system is protected against excessively high- 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.

WJIA1342E

2010 Pathfinder

REFRIGERATION SYSTEM

HA-23

< FUNCTION DIAGNOSIS >

The ECM de-energizes the A/C relay to disengage the magnetic compressor clutch when pressure on the high
pressure side detected by refrigerant pressure sensor is over about 2,746 kPa (28 kg/cm

, 398 psi), or below

about 120 kPa (1.22 kg/cm

, 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 increases to an abnormal level [more than 2,990 kPa (30.5 kg/
cm

, 433.6 psi)], the release port on the pressure relief valve automatically opens and releases refrigerant into

the atmosphere.

2010 Pathfinder

HA-24

< FUNCTION DIAGNOSIS >

OIL

OIL

Maintenance of Oil Quantity in Compressor

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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.

Oil name: NISSAN A/C System Oil Type S or equivalent

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)

2010 Pathfinder

REFRIGERATION SYSTEM

HA-25

< ON-VEHICLE MAINTENANCE >

ON-VEHICLE MAINTENANCE

REFRIGERATION SYSTEM

HFC-134a (R-134a) Service Procedure

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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 accidental 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

Shut-off valve

A/C service valve

Recovery/recycling equipment

WJIA1160E

WJIA1161E

2010 Pathfinder

HA-26

< ON-VEHICLE MAINTENANCE >

REFRIGERATION SYSTEM

Shut-off valve

A/C service valve

Recovery/recycling equipment

Refrigerant container (HFC-134a)

Refrigerant weight scale (J-39699)

Vacuum pump (J-39649)

Manifold gauge set with hoses and
couplers (J-39183-C)

HA-27, "Maintenance of Oil Quantity

in Compressor"

HA-29, "Checking of Refrigerant
Leaks"

HA-4, "Contaminated Refrigerant"

HA-29, "Checking of Refrigerant
Leaks"

HAC-21, "CONSULT-III Function
(HVAC)"

WJIA1923E

2010 Pathfinder

OIL

HA-27

< ON-VEHICLE MAINTENANCE >

OIL

Maintenance of Oil Quantity in Compressor

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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 Conditions

•

Engine speed: idling to 1,200 rpm

•

A/C switch: ON

•

Blower fan speed: HIGH

•

Temperature control: optional [set so intake air temperature is 25

to 30

C (77

to 86

F)]

•

Intake position: RECIRCULATION mode

•

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

2010 Pathfinder

HA-28

< ON-VEHICLE MAINTENANCE >

OIL

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. Confirm 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 recovery/recycling equipment. Measure oil discharged into the

recovery/recycling equipment.

5. Drain the oil from the “old” (removed) compressor 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 amount 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.

Do not add this 5 m (0.2 US fl oz, 0.2 Imp fl oz) of oil if only replacing the compressor.

New compressor

Old compressor

Recovery/recycling equipment

Measuring cup X

Measuring cup Y

New oil

Drain oil from the new compressor
into clean container

Record amount of oil recovered

Add an additional 5 m (0.2 US fl oz,
0.2 Imp fl oz) of new oil when replacing
liquid tank

Install new oil equal to recorded
amounts in measuring cups X plus Y

WJIA1716E

2010 Pathfinder

FLUORESCENT LEAK DETECTOR

HA-29

< ON-VEHICLE MAINTENANCE >

FLUORESCENT LEAK DETECTOR

Checking of Refrigerant Leaks

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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 electronic 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 leak detector probe slower and closer to the suspected leak area will

improve the chances of finding a leak.

Checking System for Leaks Using the Fluorescent Dye Leak Detector

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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). Illuminate 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 assembly 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 fluorescent 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 the 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 trigger 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 refrigerant leak detector (J-41995) to contact with any sub-

stance. This can also cause false readings and may damage the detector.

Dye Injection

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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

, 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 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.

2010 Pathfinder

Content .. 434 435 436 437 ..