Volkswagen Passat 1995 Official Factory Repair Manual page 4195

A/C refrigerant system, servicing
http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Goto&type=repair&id=VW.B4.HA01.87.5
Flush refrigerant system with compressed air and
nitrogen if:
Refrigerant oil is dark and viscous (thick)
Too much refrigerant oil is in the system
following compressor replacement
Unclear or do not know how much refrigerant oil
is in the system
Moisture, dirt or other impurities have entered
the refrigerant system (i.e. following an
accident)
Unable to pull a constant vacuum during
evacuation of a leak-free system due to
excessive moisture in the system
Refrigerant system has been open longer than
the time required for normal repairs (i.e.
following an accident)
Based on temperature and pressure
measurements, system is diagnosed with
moisture contamination
Compressor is replaced due to noises or
internal damage
Flushing is required after replacing certain
components in certain situations
Page 33 of 35
87-101
Page 87-89
12/7/2004