Refrigerant Oil
WARNING: This page is about a different car, the 2021 Audi S4 and 2021 Audi A4 Quattro. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Risk of acid burns due to atomized refrigerant oil. Eye or other body injury possible.
- Wear safety gloves.
- Wear protective eyewear.
- Never breath in atomized refrigerant oil.
- Refrigerant oil mixes with the refrigerant (about 10-40%, depending on compressor type and amount of refrigerant), circulates continuously in the circuit and lubricates the moving parts.
- In connection with R1234yf A/C system a specialized synthetic refrigerant oil for example polyalkylene glycol (PAG) oil which is matched to the refrigerant can be used as an additive. This is necessary because mineral oil for example does not mix with R1234yf a malfunction of this additive can lead to an undesirable reaction with the refrigerant or the refrigerant circuit components. In addition, the components of the R1234yf A/C system could be affected if the mixture flows through the refrigerant circuit under pressure at high temperatures or the lubricating film in the A/C compressor tears. The use of non-approved oils can lead to the failure of the A/C system and exclusive use is therefore to be made of authorized refrigerant oils.
- Type of oil for refrigerant R1234yf in motor vehicles: PAG oil with additive specified to refrigerant R1234yf (Poly-Alkylen-Glykol with specific additions).
- The most important properties are the high degree of solubility with refrigerant, good lubrication, no acid content and very minimal water content. For this reason only very specific oils may be used. Refer to Technical Data (vehicle-specific service information) for a list of the approved refrigerant oils and capacities.
- PAG oils, which are appropriate for refrigerant R1234yf, are highly hygroscopic and do not always mix with other oils. For this reason only use approved refrigerant oils.
- Moisture and acids promote aging of refrigerant oil, causing it to become dark and viscous as well as corrosive towards metals. For this reason close containers with refrigerant oil to protect it from moisture, immediately seal opened containers.
- Refrigerant oil, because of its chemical properties, must not be disposed of with engine oils or transmission oils. Dispose of refrigerant oil as a used oil of unknown origin (pay attention to local regulations).
- For refrigerant circuit with refrigerant R1234yf only the approved oil may be used for this refrigerant and the installed A/C compressor. Refer to APPROVED REFRIGERANT OILS AND REFRIGERANT OIL CAPACITIES .
- Refrigerant oil which was developed for Refrigerant R134a is not suitable for refrigerant circuits with refrigerant R1234yf (a specific additive is missing). For this reason pay attention to the correct version. Refer to APPROVED REFRIGERANT OILS AND REFRIGERANT OIL CAPACITIES (vehicle-specific service information).
- Refrigerant oil which was developed for refrigerant R1234yf, can also be suitable for refrigerant circuits with refrigerant R134a. Pay attention to the notes. Refer to Technical Data (vehicle-specific repair information).
- Do not use ester-based oils (POE oils), these are only for large system under other operating conditions (not for vehicle A/C systems).
- Do not store open containers of refrigerant oil because it is hygroscopic (attracts moisture).
- Always keep containers with refrigerant oil and the refrigerant circuit closed.