ATC-138
REFRIGERANT LINES
Revision: 2006 November2007 350Z
Checking for Refrigerant LeaksNJS00027
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 electrical leak detector or fluorescent dye leak
detector (SST: J-42220).
If dye is observed, confirm the leak with an electrical 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 electrical 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 electrical 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 DetectorNJS00028
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 electrical 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 InjectionNJS00029
(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 the 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-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
