Volkswagen Polo Service & Repair Manual: Refrigerant Oil

Volkswagen Polo Service & Repair Manual / Refrrigerant R134a Servicing / A/C System, General Information / 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, polyalkylene glycol (PAG) oil, are used in conjunction with R134a air conditioning systems. This is necessary as mineral oil, for example, does not mix with R134a. In addition, the materials of the R134a air conditioning system could be corroded as a result of mixture flowing through the refrigerant circuit under pressure at high temperatures or breakdown of the lubricating film in the compressor. Using non-approved oils can cause the HVAC system to malfunction. Only use approved oils.

Refer to the Parts Catalog.

Type of oil for R134a in motor vehicles: PAG

Note

Do not store open containers of refrigerant oil because it attracts moisture.

Always keep oil containers sealed.

Do not use old refrigerant oil over again.

Used oil disposal: Volkswagen InfoNet; Operations; Handbooks & Dealer Literature; Service Handbook; 15. Environment Protection. Follow the link “Environment Protection in Market- and Service Operations” under general information; 4. Waste Management; 6. Methods of Disposals; g. Disposing of Used Refrigerant Oil

Used refrigerant oils from systems employing halogenated hydrocarbons (at least one hydrogen atom is replaced, for example, with the halogen elements fluorine, chlorine, bromine or iodine) are to be disposed of as waste subject to special supervision. They are not to be mixed with other oils or substances. Proper storage and disposal must be ensured in line with local regulations. Refer to the chemical-climate protection provision and the recycling and disposal regulations in Germany. Different specifications and rules may apply in other countries.

German technical, work safety and accident prevention regulations can be obtained from

Addresses in other countries can be obtained from the relevant authorities.

Ester-based oils are only intended for use in large systems, not in passenger vehicle A/C systems.

Refrigerant Oil Characteristics

The most important properties are a high degree of solubility with refrigerant, good lubricity, absence of acid and minimal water content. For these reasons, only certain oils are used. A list of approved refrigerant oils and capacities can be found in the vehicle-specific repair manual. Refer to → Rep. Gr.00 or → Rep. Gr.87.

PAG oils, which are appropriate for refrigerant R134a, are highly hygroscopic and do not mix with other oils. Opened containers should therefore be closed again immediately to prevent ingress of moisture. Moisture and acids promote aging of refrigerant oil, causing it to become dark and viscous as well as corrosive towards metals.

Note

Only use oils approved for the A/C compressor in refrigerant circuits with refrigerant R134a. Refer to the vehicle-specific repair manual. Refer to → Rep. Gr.00 or → Rep. Gr.87.

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