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ATC-12
PRECAUTIONS
Revision: August 20072004 QX56
VACUUM PUMP
The lubricant contained inside the vacuum pump is not compatible
with the specified lubricant for HFC-134a (R-134a) A/C systems.
The vent side of the vacuum pump is exposed to atmospheric pres-
sure so the vacuum pump lubricant may migrate out of the pump into
the service hose. This is possible when the pump is switched off
after evacuation (vacuuming) and hose is connected to it.
To prevent this migration, use a manual valve situated near the
hose-to-pump connection, as follows.
Usually vacuum pumps have a manual isolator valve as part of
the pump. Close this valve to isolate the service hose from the
pump.
For pumps without an isolator, use a hose equipped with a man-
ual shut-off valve near the pump end. Close the valve to isolate
the hose from the pump.
If the hose has an automatic shut off valve, disconnect the hose
from the pump: as long as the hose is connected, the valve is
open and lubricating oil may migrate.
Some one-way valves open when vacuum is applied and close
under a no vacuum condition. Such valves may restrict the pump's
ability to pull a deep vacuum and are not recommended.
MANIFOLD GAUGE SET
Be certain that the gauge face indicates HFC-134a (R-134a or
134a). Make sure the gauge set has 1/2″-16 ACME threaded con-
nections for service hoses. Confirm the set has been used only with
refrigerant HFC-134a (R-134a) along with specified lubricant.
SERVICE HOSES
Be certain that the service hoses display the markings described
(colored hose with black stripe). All hoses must include positive shut-
off devices (either manual or automatic) near the end of the hoses
opposite the manifold gauge.
RHA270D
SHA5 33 D
RHA272D
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PRECAUTIONS
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SERVICE COUPLERS
Never attempt to connect HFC-134a (R-134a) service couplers to a
CFC-12 (R-12) A/C system. The HFC-134a (R-134a) couplers will
not properly connect to the CFC-12 (R-12) system. If an improper
connection is attempted, discharging and contamination may occur.
REFRIGERANT WEIGHT SCALE
Verify that no refrigerant other than HFC134a (R-134a) and specified
lubricants have been used with the scale. If the scale controls refrig-
erant flow electronically, the hose fitting must be 1/2”-16 ACME.
CHARGING CYLINDER
Using a charging cylinder is not recommended. Refrigerant may be vented into air from cylinder's top valve
when filling the cylinder with refrigerant. Also, the accuracy of the cylinder is generally less than that of an
electronic scale or of quality recycle/recharge equipment.
Wiring Diagrams and Trouble DiagnosisEJS002BO
When you read wiring diagrams, refer to the following:
GI-15, "How to Read Wiring Diagrams"
PG-4, "POWER SUPPLY ROUTING CIRCUIT"
When you perform trouble diagnosis, refer to the following:
GI-11, "How to Follow Trouble Diagnoses"
GI-27, "How to Perform Efficient Diagnosis for an Electrical Incident"
Shut-off valve rotation A/C service valve
Clockwise Open
Counterclockwise Close
RHA273D
RHA274D
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ATC-14
PREPARATION
Revision: August 20072004 QX56
PREPARATIONPFP:00002
Special Service ToolsEJS002BP
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
HFC-134a (R-134a) Service Tools and EquipmentEJS002BQ
Never mix HFC-134a refrigerant and/or its specified lubricant with CFC-12 (R-12) refrigerant and/or its lubri-
cant.
Separate and non-interchangeable service equipment must be used for handling each type of refrigerant/lubri-
cant.
Refrigerant container fittings, service hose fittings and service equipment fittings (equipment which handles
refrigerant and/or lubricant) are different between CFC-12 (R-12) and HFC-134a (R-134a). This is to avoid
mixed use of the refrigerants/lubricant.
Adapters that convert one size fitting to another must never be used refrigerant/lubricant contamination will
occur and compressor failure will result.
Tool number
(Kent-Moore No.)
Tool nameDescription
—
(J-38873-A)
Drive plate installerInstalling pulley and drive plate
KV99233130
(J-29884)
Pulley pullerRemoving pulley
WJIA0367E
LHA172
Tool number
(Kent-Moore No.)
Tool nameDescription
HFC-134a (R-134a) refrigerant Container color: Light blue
Container marking: HFC-134a (R-
134a)
Fitting size: Thread size
large container 1/2"-16 ACME
KLH00-PAGS0
(—)
Nissan A/C System Oil Type DH-
PSType: Poly alkylene glycol oil (PAG),
type DH-PS
Application: HFC-134a (R-134a)
swash plate compressors (Nissan
only)
Lubricity: 40 m (1.4 US fl oz, 1.4 Imp
fl oz)
KV991J0130
(ACR2005-NI)
ACR A/C Service CenterRefrigerant recovery, recycling and re-
charging
S-NT196
S-NT197
WJIA0293E
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PREPARATION
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(J-41995)
Electronic refrigerant leak detectorPower supply:
DC 12V (battery terminal)
(J-43926)
Refrigerant dye leak detection kit
Kit includes:
(J-42220)
UV lamp and UV safety goggles
(J-41459)
Refrigerant dye injector
(J-41447)
HFC-134a (R-134a) Fluorescent
leak detection dye
(Box of 24, 1/4 ounce bottles)
(J-43872)
Refrigerant dye cleanerPower supply:
DC 12V (battery terminal)
(J-42220)
UV lamp and UV safety gogglesPower supply:
DC 12V (battery terminal)
For checking refrigerant leak when flu-
orescent dye is installed in A/C system.
Includes: UV lamp and UV safety gog-
gles
(J-41447)
HFC-134a (R-134a) Fluorescent
leak detection dye
(Box of 24, 1/4 ounce bottles)Application: For HFC-134a (R-134a)
PAG oil
Container: 1/4 ounce (7.4cc) bottle
(Includes self-adhesive dye identifica-
tion labels for affixing to vehicle after
charging system with dye.)
(J-41459)
HFC-134a (R-134a) Dye injector
Use with J-41447, 1/4 ounce bottleFor injecting 1/4 ounce of fluorescent
leak detection dye into A/C system.
(J-43872)
Refrigerant dye cleanerFor cleaning dye spills. Tool number
(Kent-Moore No.)
Tool nameDescription
AHA2 81 A
ZHA2 00 H
SHA438F
SHA439F
SHA440F
SHA441F
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ATC-16
PREPARATION
Revision: August 20072004 QX56
(J-39183-C)
Manifold gauge set (with hoses
and couplers)Identification:
The gauge face indicates R-134a.
Fitting size-Thread size
1/2"-16 ACME
Service hoses
High side hose
(J-39500-72B)
Low side hose
(J-39500-72R)
Utility hose
(J-39500-72Y)
Hose color:
Low side hose: Blue with black stripe
High side hose: Red with black stripe
Utility hose: Yellow with black stripe
or green with black stripe
Hose fitting to gauge:
1/2"-16 ACME
Service couplers
High side coupler
(J-39500-20A)
Low side coupler
(J-39500-24A)
Hose fitting to service hose:
M14 x 1.5 fitting is optional or perma-
nently attached.
(J-39699)
Refrigerant weight scaleFor 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 nameDescription
RJIA0196E
S-NT201
S-NT202
S-NT200
S-NT203
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PREPARATION
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Commercial Service ToolsEJS002BR
Tool nameDescription
(J-41810-NI)
Refrigerant identifier equipment-
(R-134a)For checking refrigerant purity and
system contamination
Power toolLoosening bolts and nuts
(J-44614)
Clutch disc holding toolClutch disc holding tool
RJIA0197E
PBIC0190E
WHA230
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ATC-18
REFRIGERATION SYSTEM
Revision: August 20072004 QX56
REFRIGERATION SYSTEMPFP:KA990
Refrigerant CycleEJS002BS
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 ProtectionEJS002BT
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.
The ECM deenergizes 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
2 , 398 psi), or below
about 120 kPa (1.22 kg/cm
2 , 17.4 psi).
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REFRIGERATION SYSTEM
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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
2 , 433.6 psi)], the release port on the pressure relief valve automatically opens and releases refrigerant
into the atmosphere.
WJIA1342E