Vehicle Damage Warnings
Air conditioning systems are extremely sensitive to moisture and dirt. Importance of clean working conditions is extremely important, as smallest particle of foreign matter in an air conditioning system will contaminate refrigerant, causing rust, ice or damage to compressor. For this reason, all replacement parts are sold in vacuum sealed containers and should not be opened until they are to be installed in system. If, for any reason, a part has been removed from its container for any length of time, part must be completely flushed remove any dust or moisture that may have accumulated during storage. In cases of collision repairs where system has been open for any length of time, entire system must be purged completely and a new receiver-drier must be installed because element of existing unit will have become saturated and unable to remove any moisture from system once system is recharged.
When making gauge connections, purge gauge lines first by cracking charging valve and allowing a small amount of refrigerant to flow through lines, then connect lines immediately. After disconnecting gauge lines, check valve areas to be sure Schrader valves are not leaking.
Cleanliness is especially important when servicing compressors because of very close tolerances used in these units. Consequently, repairs to compressor itself should not be attempted unless all proper tools are at hand and a virtually spotless work area is provided.
Use care when disconnecting or connecting refrigerant lines. Always use a back-up wrench and be careful not to overtighten any connection. Overtightening may result in a line or flare seat distortion and a system leak.
R-134a systems require use of special service equipment designed specifically for R-134a systems. R-12 servicing equipment cannot be used on R-134a systems.
Major components of R-134a air conditioning systems are similar to those used previously on R-12 fixed orifice tube type systems. R-12 and R-134a components are similar in design and function. As a result, all diagnosis and testing procedures for R-12 components can be used for R-134a system components. However, it should be noted that R-134a system components can only be replaced with other R-134a components. R-134a components cannot be replaced with components used with R-12 systems. Same rule applies for R-12 components, they cannot be replaced with R-134a components. To identify which type of air conditioning system a particular vehicle has, visually inspect system for identification tags located on major components. R-134a system components have yellow R-134a NON-CFC tags.
Refrigerant oil required for R-134a air conditioning systems is a Polyalkylene Glycol (PAG) oil, Ford specification part No. WSH-M1C231-B, or equivalent. This type of refrigerant oil is designed specifically for R-134a systems and is not suitable for use in R-12 systems. Never use an R-134a refrigerant oil in R-12 systems. Never use R-12 refrigerant oil YN-9 in R-134a systems.