Audi Q5: O-Ring Seals
These rings seal off the connection points between individual components of the refrigerant circuit.
Only O-rings that are resistant to refrigerant R134a and refrigerant oil must be installed. Make sure they are original replacement parts.
O-ring seals:
- Always use only once.
- Make sure diameters -a- and -b- are correct.
- Coat with refrigerant oil before installing. Refer to → Heating, Ventilation and Air Conditioning; Rep. Gr.87; System Overview - Refrigerant Circuit (vehicle-specific repair manual) and the Parts Catalog.
Note
The color coding of refrigerant circuit O-rings with R134a has been discontinued. Black and colored O-rings are used. Refer to the Parts Catalog and → Heating, Ventilation and Air Conditioning; Rep. Gr.87; System Overview - Refrigerant Circuit (vehicle-specific repair manual).
Refrigerant Circuit Pipes and Hoses
The mixture of refrigerant oil and refrigerant R134a corrodes certain metals (such as copper) and alloys and dissolves some hose materials. Therefore use original replacement parts only.
Pipes and hoses are joined by threaded connections or special plug connectors.
Note
Observe specified torque for threaded connections, use appropriate release tools for plug connectors.
Pressure Relief Valve
The pressure relief valve is installed on the A/C compressor or receiver/dryer.
At a pressure of approximately 38 bar (551 psi) positive pressure, valve opens and closes again once pressure has dissipated (approximately 30 bar (435 psi) ).
Refrigerant does not escape completely.
Note
- Depending on the version, a transparent plastic disc -B- may be installed on the pressure relief valve -A-, which breaks off as soon as the valve is activated.
- Depending on the pressure relief valve version -A-, an additional cover -C- can be slid onto the pressure relief valve -A-. If the pressure in the refrigerant circuit does rise above the pressure relief valve -A- opening pressure and the valve opens, the refrigerant does not escape in one direction, but rather it is distributed through the openings -D- under the cover -C-.
Check Valves
The check valves disconnect in different areas of the refrigerant circuit.
Note
- The illustrated check valve -3- if for example installed on an Audi Q7 e-tron
- The check valves in the refrigerant circuit in the flow direction have a specified residual pressure, approximately 0.1 bar or 100 mbar (1.5 psi). So that the refrigerant circuit can be completely evacuates (residual pressure less than 5 mbar (0.10 psi) ) all electrically activated valves must be opened.
- Depending on the version the flow direction can be marked using a sticker.
