Audi A4: Finding Leaks via Vacuum Test using A/C Service Station or Nitrogen Pressure Testing

Vehicles with a High Voltage System (Hybrid Vehicles)

Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system. Refer to → Chapter "Warnings when Working on Vehicles with High Voltage System" and → Electrical Equipment; Rep. Gr.93; General Warnings when Working on High Voltage System.

All vehicles

- Turn off the ignition.

• For finding leaks via the vacuum test using the A/C service station or nitrogen pressure testing. Refer to → Chapter "Refrigerant Circuit, Discharging with Service Station".

  Note

• Small leaks (less than 100 g of refrigerant loss per year) are not often detected with the vacuum test or with the nitrogen pressure test. The incoming air and the amount of nitrogen flowing out is too small to be able to locate the faulty location based on noise.
• Leaks on the refrigerant circuit that are greater than 100 g of refrigerant loss each year are also not always detectable with the vacuum test or with the nitrogen pressure test, depending on the ambient conditions (ambient noise, leak location etc.). The incoming air and the quantity of nitrogen flowing out is currently too small to detect any noise and locate the faulty location.
• Larger leaks on the refrigerant circuit (for example, an impact from a rock on the condenser, refrigerant loss greater than 100 g per year) can be detected, for example by noise, using the vacuum test or the nitrogen pressure test. Refer to → Chapter "Refrigerant Circuit, Discharging with Service Station".

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