PRECAUTIONS
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Revision: 2006 November2007 350Z
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 to the manifold gauge.
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. However, if an
improper connection is attempted, discharging and contamination
may occur.
REFRIGERANT WEIGHT SCALE
Verify that no refrigerant other than HFC-134a (R-134a) and speci-
fied lubricants have been used with the scale. If the scale controls
refrigerant 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
electrical scale or of quality recycle/recharge equipment.
RHA272D
Shut-off valve rotation A/C service valve
Clockwise Open
Counterclockwise Close
RHA273D
RHA274D
ATC-86
TROUBLE DIAGNOSIS
Revision: 2006 November2007 350Z
TROUBLE DIAGNOSIS FOR UNUSUAL PRESSURE
Whenever system’s high and/or low side pressure(s) is/are unusual, diagnose using a manifold gauge. The
marker above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the
standard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air tempera-
ture-to-operating pressure table).
Both High- and Low-pressure Sides are Too High
High-pressure Side is Too High and Low-pressure Side is Too Low
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too high.The pressure returns to normal
soon after water is splashed on
condenser.Excessive refrigerant charge
in refrigeration cycle.Reduce refrigerant until speci-
fied pressure is obtained.
Air suction by cooling fan is
insufficient.Insufficient condenser cooling
performance.
↓
1. Condenser fins are clogged.
2. Improper fan rotation of
cooling fan.
Clean condenser.
Check and repair cooling
fan as necessary.
Low-pressure pipe is not
cold.
When compressor is
stopped high-pressure value
quickly drops by approxi-
mately 196 kPa (2 kg/cm
2 ,
28 psi). It then decreases
gradually thereafter.Poor heat exchange in con-
denser
(After compressor operation
stops, high-pressure
decreases too slowly.).
↓
Air in refrigeration cycle.Evacuate repeatedly and
recharge system.
Engine tends to overheat.Engine cooling systems mal-
function.Check and repair each engine
cooling system.
An area of the low-pressure
pipe is colder than areas
near the evaporator outlet.
Low-pressure pipe is some-
times covered with frost.
Excessive liquid refrigerant
on low-pressure side.
Excessive refrigerant dis-
charge flow.
Expansion valve is open a
little compared with the
specification.
↓
Improper expansion valve
adjustment.Replace expansion valve.
AC359A
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too high and
low-pressure side is too low.
Upper side of condenser and
high-pressure side are hot,
however, liquid tank is not so
hot.High-pressure tube or parts
located between compressor
and condenser are clogged or
crushed.
Check and repair or replace
malfunctioning parts.
Check lubricant for contami-
nation.
AC360A
HEATER & COOLING UNIT ASSEMBLY
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12. Remove mounting bolts from heater & cooling unit assembly.
13. Remove steering column assembly mounting nuts and bolt.
14. Remove steering member mounting bolts, and then remove steering member.
15. Remove heater & cooling unit assembly.
INSTALLATION
Installation is basically the reverse order of removal.
CAUTION:
Replace O-rings of low-pressure pipe 2 and high-pressure pipe 1 with new ones, and then apply
compressor oil to it when installing it.
Female-side piping connection is thin and easy to deform. Slowly insert the male-side piping
straight in axial direction.
Insert piping securely until a click is heard.
After piping connection is completed, pull male-side piping by hand to make sure that connection
does not come loose.
When recharging refrigerant, check for leaks.
NOTE:
When filling radiator with coolant, refer to CO-10, "Changing Engine Coolant" .
Recharge the refrigerant.
SJIA1221E
SJIA1222E
Heater & cooling unit assembly mounting bolts
: 6.9 N·m (0.7 kg-m, 61 in-lb)
Steering member and steering column assembly mounting nuts and bolt
: 12 N·m (1.2 kg-m, 9 ft-lb)
ATC-140
REFRIGERANT LINES
Revision: 2006 November2007 350Z
CHECKING PROCEDURE
To prevent inaccurate or false readings, make sure there is no refrigerant vapor, shop chemicals, or cigarette
smoke in the vicinity of the vehicle. Perform the leak test in calm area (low air/wind movement) so that the
leaking refrigerant is not dispersed.
1. Stop the engine.
2. Connect a suitable A/C manifold gauge set (SST:J-39183) to the A/C service valves.
3. Check if the A/C refrigerant pressure is at least 345 kPa (3.52 kg/cm
2 , 50 psi) above 16°C (61°F). If less
than specification, recover/evacuate and recharge the system with the specified amount of refrigerant.
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).
4. Perform the leak test from the high-pressure side (compressor discharge a to evaporator inlet g) to the
low-pressure side (evaporator drain hose h to shaft seal l). Refer to ATC-125, "
Components" . Perform a
leak check for the following areas carefully. Clean the component to be checked and move the leak
detected probe completely around the connection/component.
Compressor
Check the fitting of high- and low-pressure flexible hoses, relief valve and shaft seal.
Condenser
Check the fitting of high-pressure flexible hose and pipe.
Liquid tank
Check the fitting of refrigerant connection.
Service valves
Check all around the service valves. Ensure service valve caps are secured on the service valves (to pre-
vent leaks).
NOTE:
After removing A/C manifold gauge set from service valves, wipe any residue from valves to prevent any
false readings by leak detector.
Cooling unit (Evaporator)
With engine OFF, turn blower fan on “High” for at least 15 seconds to dissipate any refrigerant trace in the
cooling unit. Wait a minimum of 10 minutes accumulation time (refer to the manufacturer’s recommended
procedure for actual wait time) before inserting the leak detector probe into the drain hose.
Keep the probe inserted for at least 10 seconds. Use caution not to contaminate the probe tip with water
or dirt that may be in the drain hose.
5. If a leak detector detects a leak, verify at least once by blowing compressed air into area of suspected
leak, then repeat check as outlined above.
6. Do not stop when one leak is found. Continue to check for additional leaks at all system components.
If no leaks are found, perform steps 7 - 10.
7. Start the engine.
8. Set the A/C control as follows;
a. A/C switch: ON
b. MODE door position: VENT (Ventilation)
c. Intake door position: Recirculation
d. Temperature setting: Max. cold
e. Fan speed: High
9. Run engine at 1,500 rpm for at least 2 minutes.
10. Stop the engine and perform leak check again following steps 4
through 6 above.
Refrigerant leaks should be checked immediately after stopping
the engine. Begin with the leak detector at the compressor. The
pressure on the high-pressure side will gradually drop after
refrigerant circulation stops and pressure on the low-pressure
side will gradually rise, as shown in the graph. Some leaks are
more easily detected when pressure is high.
SHA839E
REFRIGERANT LINES
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11. Before connecting recovery/recycling recharging equipment to vehicle, check recovery/recycling recharg-
ing equipment gauges. No refrigerant pressure should be displayed. If pressure is displayed, recover
refrigerant from equipment lines and then check refrigerant purity.
12. Confirm refrigerant purity in supply tank using recovery/recycling recharging equipment and refrigerant
identifier.
13. Confirm refrigerant purity in vehicle A/C system using recovery/recycling recharging equipment and refrig-
erant identifier.
14. Discharge A/C system using approved refrigerant recovery/recycling recharging equipment. Repair the
leaking fitting or component if necessary.
15. Evacuate and recharge A/C system and perform the leak test to confirm no refrigerant leaks.
16. Perform A/C performance test to ensure system works properly.