Leak test using inert gas

4. Operate the refrigerant evacuation system LEAK TEST SYSTEM according to the manufactures instructions. The following instructions refer to an electronic type NOTE: If the vacuum reading is below 700 Refrigerant Leak Detector for use with R134a, which mm Hg, 28 in Hg after 15 minutes, suspect is the safest and most sensitive. a leak in the system. Partially recharge the

system and check for leaks using an electronic leak tester. Check suction lines first, then run the compressor for 5 minutes and then check the high pressure lines.

• CAUTION: The system must be Evacuated
• immediately before recharging
• commences. Delay between Evacuation
• and Recharging is not permitted.

5. Operate the refrigerant recharging system according to the manufacturer’s instructions.

Refrigerant to charge system = 900 ± 30gm, 32 ± 1 oz.

6. If the full charge has not been accepted by the system, start the engine and run it at 1500 rev/min for a minimum of 2 minutes. Switch on the air conditioning system, open the vehicle windows, set the temperature control to cold and switch the blower to maximum speed.
7. Consult Refrigerant Station Manual for correct procedure to complete the charge.
8. Carry out the air conditioning system performance test.

Leak test using inert gas

Use Nitrogen or Helium gas.

• CAUTION: When a major repair has been
• carried out, a leak test should be carried
• out using an inert gas (see below).

1. Place the vehicle in a well ventilated area but free from draughts, as leakage from the system could be dissipated without detection.
2. Follow the instructions issued by the manufacturer of the particular leak detector being used.
3. Commence searching for leaks by passing the detector probe around all joints and components, refrigerant gas is heavier than air.
4. Insert the probe into an air outlet of the evaporator or into the evaporator drain tube. Switch the air conditioning blower on and off at intervals of ten seconds. Any leaking refrigerant will be gathered in by the blower and detected.
5. Insert the probe between the magnetic clutch and compressor to check the shaft seal for leaks.
6. Check all service valve connections, valve plate, head and base plate joints and back seal plate.
7. Check the condenser for leaks at the pipe unions.
8. If any leaks are found, the system must be discharged before rectification.
9. Rectify any leaks and recheck for leaks during evacuation prior to charging.
1. Connect gas line to recharging station.₂
2. Pressurise system to 3 bar (45 lbf/in ).
3. Carry out leak test as above.