9-3 Convertible (9400) L4-2.0L Turbo (B205) (2000)
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Hose/Line HVAC: Description and Operation
Compressor Oil And Hoses
In the A/C system, PAG-oil is used. (polyalcyleneglycol), a fully synthetic oil of the glycol type. PAG-type oil is very hygroscopic, that is, it readily
absorbs moisture from the air, much the same as brake fluid. The water is chemically bound in the oil and cannot be removed by vacuum pumping.
Therefore, it is very important that the oil is stored in closed containers and that it is not exposed to air other than for short periods of time. The oil is
supplied in 20 ml tubes to minimize the risk of left-over oil being stored and used the next time. If the connections in the A/C system are opened, they
must be plugged immediately to prevent moisture from entering the system. There are special plugs for this purpose that can be ordered.
Hoses, pipes and O-rings
The pipes and hoses in the A/C system must pass very stringent requirements with respect to tolerance to heat and pressure. They must also pass
requirements for sealing characteristics against leaks and, for hoses, diffusion. Diffusion indicates when refrigerant leaks out through the material.
Therefore, use only pipes and hoses specially manufactured for the A/C system.
In order to meet these requirements, the hoses have an inside made of butyl rubber and an outside of EPDM-rubber. The hoses are also provided with
heat protection on exposed sections.
The O-rings are manufactured of a special hydrated nitril rubber. They must be lubricated using synthetic vaseline before being mounted in the A/C
system. Always use new O-rings when installing A/C system components.
