Volkswagen Polo Service & Repair Manual: A/C Service and Recycling Units

Pressure Gauge, Tests and Measurements

Indicators on pressure gauge 1 -  Temperature scale for refrigerant R134a CF3–CH2F or CH2F–CF3. 2 -&nb ...

Extraction System Group Classifications

At this time, A/C service units for extracting, cleaning and filling refrigerant for motor vehicle A/C systems are available from various manufacturers. ...

Other materials:

Original Products
Paint Products in Service   Note For guarantee and warranty work, Volkswagen AG advises to use only original Volkswagen products or paint supplier products that are approved by the manufacturer according to manufacturer spec ...

Refrigerant Circuit with A/C Service Station, Filling
  Caution If it is suspected that chemicals were added to the refrigerant circuit to seal leaks, do not connect the A/C service station and do not extract the refrigerant. ...

Refrigerant Oil
Refrigerant oil mixes with the refrigerant (about 20 - 40%, depending on compressor type and amount of refrigerant) and circulates constantly in the system, lubricating the moving parts. Special synthetic refrigerant oils, for example, ...