Audi A2 2001 - Page 65

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2.1.7 Expansion Valve
The expansion valve atomizes the streaming refrigerant and con‐
trols the flow quantity so that the vapor is gaseous only at the
evaporator outlet, depending on the heat transmission.
Note
♦ Be sure to use the correct part number when replacing the
expansion valve. Refer to Electronic Parts Catalog (ETKA).
♦ Different characteristic curves matched to the appropriate cir‐
cuit. Refer to ⇒ Heating, Ventilation and Air Conditioning; Rep.
Gr. 87 ; Description and Operation (vehicle-specific repair
manual) and Electronic Parts Catalog (ETKA).
♦ Depending on the A/C compressor version, there may be a
valve installed on the high pressure side of the A/C compres‐
sor, which prevents the liquid refrigerant from flowing back into
the compressor once the A/C is turned off. If an A/C compres‐
sor with this valve is installed in a vehicle with a refrigerant
circuit having an expansion valve, then it may take some time
until the pressure in the high pressure side decreases (the ex‐
pansion is cold and the pressure in the low pressure side
quickly increases after it is turned off, the expansion valve
closes and the refrigerant flows slowly into the low pressure
side). If the A/C compressor is switched on, the pressure on
the low pressure side goes down, the expansion valve open
and the refrigerant can flow of the low pressure side.
Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A2 2001 ➤ , A ...
Refrigerant R134a Servicing - Edition 01.2011
2. Description and Operation 61