Infiniti Q45. Manual - part 141

REFRIGERANT LINES

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ATC

Removal and Installation of Evaporator

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REMOVAL

1.

Remove heater & cooling unit assembly. Refer to 

ATC-135, "HEATER & COOLING UNIT ASSEMBLY"

 .

2.

Remove cooler grommet, expansion valve cover, expansion valve. Refer to 

ATC-159, "Removal and

Installation of Expansion Valve"

 .

3.

Remove air mix door motor (driver side) and mode door motor (driver side) with bracket attached. Refer to

ATC-141, "AIR MIX DOOR MOTOR"

  and 

ATC-140, "MODE DOOR MOTOR"

 .

4.

Remove evaporator cover.

5.

Slide evaporator, and then remove it from heater & cooling unit
assembly.

6.

Remove intake sensor from evaporator, and then remove evap-
orator.

INSTALLATION

Installation is basically the reverse order of removal.

CAUTION:

●

Replace O-rings of low-pressure flexible hose and high-pressure pipe with new ones, and then
apply compressor oil to it when installing it.

●

Mark mounting position of intake sensor bracket prior to removal so that the reinstalled sensor
can be located in the same position.

●

When recharging refrigerant, check for leaks.

Removal and Installation of Expansion Valve

NJS0009S

REMOVAL

1.

Remove engine cover and air cleaner cover, using power tools. Refer to 

EM-13, "ENGINE ROOM

COVER"

 .

2.

Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.

3.

Drain coolant from cooling system and disconnect heater hoses.
Refer to 

CO-8, "Changing Engine Coolant"

 .

4.

Disconnect low-pressure flexible hose and high-pressure pipe
from evaporator.

CAUTION:

Cap or wrap the joint of low-pressure flexible hose and
high-pressure pipe with a suitable material such as a vinyl
tape to avoid the entry of air.

5.

Remove mounting screw, and then remove expansion valve
cover.

6.

Remove mounting bolts, and then remove expansion valve.

SJIA1310E

RJIA0318E

RJIA0334E

ATC-160

REFRIGERANT LINES

INSTALLATION

Installation is basically the reverse order of removal.

CAUTION:

●

Replace O-rings of evaporator with new ones, and then apply compressor oil to it when installing
it.

●

When recharging refrigerant, check for leaks.

REFRIGERANT LINES

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ATC

Checking for Refrigerant Leaks

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Perform a visual inspection of all refrigeration parts, fittings, hoses and components for signs of A/C lubricant
leakage, damage and corrosion. A/C lubricant leakage may indicate an area of refrigerant leakage. Allow
extra inspection time in these areas when using either an electronic refrigerant leak detector or fluorescent
dye leak detector (SST: J-42220).
If dye is observed, confirm the leak with an electronic refrigerant leak detector. It is possible a prior leak 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 leak detector, move the probe along the suspected
leak area at 1 to 2 inches per second and no further than 1/4 inch from the component.

CAUTION:

Moving the electronic 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 Leak Detector

NJS0009U

1.

Check A/C system for leaks using the UV lamp and safety goggles (SST: 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 evaporator drain open-
ing indicates an evaporator core assembly (tubes, core or expansion valve) leak.

2.

If the suspected area is difficult to see, use an adjustable mirror or wipe the area with a clean shop rag or
cloth, with the UV lamp for dye residue.

3.

After the leak is repaired, remove any residual dye using dye cleaner (SST: J-43872) to prevent future
misdiagnosis.

4.

Perform a system performance check and verify the leak repair with an approved electronic refrigerant
leak detector.

NOTE:
Other gases in the work area or substances on the A/C components, for example, anti-freeze, windshield
washer fluid, solvents and lubricants, 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 detector to contact with any substance. This can also cause false readings
and may damage the detector.

Dye Injection

NJS0009V

(This procedure is only necessary when recharging the system or when the compressor has seized and was
replaced.)

1.

Check 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 (1/4 ounce / 7.4 cc) of the A/C refrigerant dye into the injector tool (SST: J-41459).

3.

Connect the injector tool to the A/C low-pressure side service valve.

4.

Start engine and switch A/C ON.

5.

When the A/C operating (compressor running), inject one bottle (1/4 ounce / 7.4 cc) of fluorescent dye
through the low-pressure service valve using dye injector tool (SST: J-41459) (refer to the manufacture’s
operating instructions).

6.

With the engine still running, disconnect the injector tool from the service valve.

CAUTION:

Be careful the A/C system or replacing a component, pour the dye directly into the open system
connection and proceed with the service procedures.

7.

Operate the A/C system for a minimum of 20 minutes to mix the dye with the system oil. Depending on the
leak size, operating conditions and location of the leak, it may take from minutes to days for the dye to
penetrate a leak and become visible.

8.

Attach a blue label as necessary.

ATC-162

REFRIGERANT LINES

Electronic Refrigerant Leak Detector

NJS0009W

PRECAUTIONS FOR HANDLING LEAK DETECTOR

When performing a refrigerant leak check, use an A/C electrical leak
detector (SST) or equivalent. Ensure that the instrument is calibrated
and set properly as per the operating instructions.
The leak detector is a delicate device. In order to use the leak detec-
tor properly, read the operating instructions and perform any speci-
fied maintenance.

1.

Position probe approximately 5 mm (3/16 in) away from point to
be checked.

2.

When testing, circle each fitting completely with probe.

3.

Move probe along component approximately 25 to 50 mm (1 to
2 in)/sec.

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SHA706E

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