1. Never disconnect any part of the air conditioning refrigeration circuit unless the system has been discharged by your Audi dealer or specialist.
2. If the compressor or condenser makes it difficult to repair the engine, then it is permissible to unscrew them and move them within the deflection of the flexible hose, but do not disconnect the hoses. If it is still not possible to perform the required work, then the system must be discharged.
3. After the work has been completed, the system must be recharged.
4. Check the condenser regularly and clean it from dirt.
5. Check the tension of the compressor drive belt regularly. The belt sag should be approximately 5 mm, at the center point of the longest section. The number of shims between the halves of the crankshaft pulley can be adjusted to adjust the belt tension on 4-cylinder engines. On 5-cylinder engines, the tension can be adjusted as follows. Loosen the two mounting bolts, then loosen the lock nut and rotate the fastening nut in the desired direction. After adjustment, tighten the lock nut.
(Content source: the specified website AudiManual.ru)