Jul 5, 2015
How often or when does the system need re gassing or re charging
Unless you feel the system is not working as it once did then have it checked out, otherwise don't worry
And don't listen to anyone saying the refrigerant goes off....its a pure fluid...
Systems leak more if not used as the oil needs to circulate to coat the hoses and seals.
If they dry out the refrigerant seeps out quicker.
Everything leaks but Audi's are pretty good and unless its get damaged they keep together for 5 years plus.
On a hot day (say 25C) on LO you should measure 5C or better at the vent on full fan.
Just a rule of thumb..more technical stuff in the workshop guide of course.
The only part that needs oil is the compressor and the shaft seal.
The flexible hoses by their nature are more porous than metallic materials and a necessary evil in engine bays. The hoses remain flexible due to the oily plasticisers used in their manufacture. Fluorocarbons such as R134a lacking the chlorine of CFCs that used to coat all surfaces also extract these plasticisers over time that can leave hoses hard/brittle. The lubricant normally PAO that lubricates the compressor and face seal also coats the hose internals off setting that degradation. At a molecular level the oil coating also reduces loses through capillary type action through low density materials and metallic grain boundaries.
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