Volkswagen Passat 1995 Official Factory Repair Manual page 4159

A/C refrigerant system
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Evaporator
Liquid refrigerant entering the evaporator absorbs
heat from air passing through the evaporator fins and
cools the air. As the refrigerant absorbs heat it turns
to vapor and then is suctioned by the compressor.
A/C system hoses and lines
The mixture of refrigerant oil (PAG oil) and refrigerant
R-134a attacks some metals and alloys (for example,
copper) and breaks down certain hose material.
Where applicable, hoses and lines may be identified
with a green mark (stripe) or the lettering "R-134a".
Hoses and lines are fastened together with threaded
couplings/fittings and are retained (to bodywork or
components) with specially isolated hose clamps.
Notes:
During servicing, all couplings, fittings and related
fasteners must be torqued to specifications
Page 87-69 .
Ensure that only special tools (as specified) are
used while servicing.
Page 4 of 7
87-65
12/7/2004