Audi A4 2001 - Page 35

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Note the following points to prevent oil and moisture from entering
the refrigerant circuit from the compressed air system.
– The compressed air must be routed through a compressed air
purifier for cleaning and drying. Use is therefore to be made of
filter and dryer for compressed air (included in scope of deliv‐
ery as tool for painting work). Refer to Special Tools and
Equipment catalog.
– On refrigerant lines with thread or union nut on the connection,
use adapter from Adapter set -V.A.G 1785- ( Adapter -V.A.G
1785/1- to Adapter -V.A.G 1785/8- ) to connect charge hoses
5/8" -18 UNF (a section of this adapter is also contained in the
VW/Audi passenger vehicle set adapter chest -VAS 6338/1- ).
– On refrigerant lines without thread or union nut on the con‐
nection (for connecting adapters), use adapter from VW/Audi
passenger vehicle set adapter chest -VAS 6338/1- or a stand‐
ard blower pistol with rubber mouthpiece.
Note
♦ Only blow through refrigerant circuit with compressed air and
then with nitrogen if there is no possibility of flushing the re‐
frigerant circuit or the amount of work to flush individual com‐
ponents becomes excessive (such as minor contaminants and
moisture can also be blown out of the refrigerant lines in a short
period of time).
♦ Compressed air/nitrogen emerging from components is to be
drawn off by way of an appropriate system (such as workshop
extraction system).
The circuit (or individual components) must be blown through (if
there is no possibility for flushing or flushing is not recommended)
– In the event dirt or other contaminants are located in individual
components of the circuit.
– If vacuum reading is not maintained on evacuating a leak-free
refrigerant circuit (pressure build-up due to moisture in refrig‐
erant circuit).
– If refrigerant circuit has been left open for longer than normal
(such as following an accident).
– Pressure and temperature measurements in the refrigerant
circuit indicate the likelihood of moisture.
– In the event of doubt about the amount of refrigerant oil in the
circuit.
– The A/C compressor had to be replaced on account of internal
damage (such as noise or no output).
– If stipulated by the vehicle-specific repair manual following re‐
placement of certain components.
Note
Certain contaminants and old refrigerant oil cannot or can only be
insufficiently removed from the refrigerant circuit with com‐
pressed air, these contaminants can be removed, for example by
flushing with refrigerant R134a. Refer to
⇒ “1.4.13 Refrigerant Circuit Flushing With Refrigerant R134a“,
page 32 .
♦ Refrigerant Circuit, flushing, refer to
⇒ “1.4.11 Refrigerant Circuit, Flushing“, page 28 .
Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A2 2001 ➤ , A ...
Refrigerant R134a Servicing - Edition 01.2011
1. General Information 31