Volkswagen Golf 1999 Service Manual page 4063

Pressures, checking on vehicles
Note:
- If the problem is with the A/C
Compressor Regulator Valve
N280 (regulating valve is not
actuated but compressor operates
nevertheless), refrigerant circuit
does not have to be flushed. It is
sufficient in this case to replace
the compressor (adjust quantity of
refrigerant oil in compressor).
- If expansion valve is
malfunctioning (permanently
closed or does not open
sufficiently), A/C Compressor
Regulator Valve N280 is actuated
to maximum output and low
pressure drops to value in graph
or below (compressor draws off
refrigerant from low-pressure
side). As however refrigerant
cannot flow via expansion valve,
cooling output is not attained and
http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Next&type=repair&id=...
- Expansion valve or compressor
malfunctioning.
- A/C compressor malfunctioning. - Discharge refrigerant circuit.
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- Flush refrigerant circuit with
compressed air and nitrogen.
- Re-charge refrigerant circuit.
- Repeat test.
- Discharge refrigerant circuit.
- Replace expansion valve and
receiver.
- Re-charge refrigerant circuit.
- Repeat test, if function is not
- Replace A/C compressor.
- Replace A/C compressor.
- If quantity of refrigerant extrac
is substantially greater than
specified capacity:
- Re-charge refrigerant circuit.
- Repeat test.
13/2/2005