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".
READ NEXT:
Possible Refrigerant Circuit Concerns
Test Requirements
Electrical Equipment, vacuum system and air duct
fault-finding has not revealed any faults. Refer to Guided Fault
Finding for the A/C system
Vehicles with a High Voltage System (Hybrid Vehicles)
Extremely Dangerous Due to High-Voltage
The high-voltage system is under high-voltage. Death or serious
bodily injury by electric shock.
- I
SEE MORE:
Intake Air Temperature Sensor -G42-/Manifold Absolute Pressure Sensor
-G71-, Removing and Installing
All procedures are described under:
→ Servicing - 4-Cylinder 2.0L 4V TFSI Engine; Rep. Gr.24; Sensors; Intake Air
Temperature Sensor G42/Manifold Absolute Pressure SensorG71, Remo
Special tools and workshop equipment required
Torque Wrench 1331 5-50Nm -VAG1331-
Engine and Gearbox Jack -VAS6931-
Puller - Ball Joint -T40043-
Gearbox Support -T40173-
Locating Pin -T40334-
Caution
This procedure contains mandatory replaceable parts.
Refer to component overview an