A/C SYSTEM GENERAL SERVICING
Other Means Of Identification
Refrigerant R-134a, when viewed through a sight glass, may
have a "milky" appearance due to the mixture of refrigerant and
lubricating oil. As the refrigerant and oil DO NOT exhibit a "clear"
sight glass on a properly charged A/C system, R-134a systems have no
sight glass.
Audi, Mercedes-Benz and Volkswagen use Green bands/labels on
condenser, refrigerant lines, receiver-drier and expansion valve.
Lexus A/C system hoses and line connectors have a groove, a White line
and "R-134a" marked on them. See Fig. 3.