Refrigerant Lines, Disconnecting and Connecting From Expansion Valve
Refrigerant Lines, Disconnecting and Connecting From Expansion Valve
• After switching off the A/C compressor in this vehicle, it may take a relatively long time for the pressure on the high pressure side to decrease. This is because the expansion valve is cold and the pressure on the low pressure side increases quickly after shutting the compressor off, then the expansion valve closes and the refrigerant flows slowly to the low pressure side.
Removing
- Switch off ignition.
- Discharge refrigerant circuit.
- Remove components which hinder access to mounting points - A - on heat shield - B - in engine compartment.
• For the sake of clarity, the illustration shows the heat shield - B - with the engine removed.
• Depending on the engine and type of vehicle, it may be necessary to loosen or remove various engine components.
Components, that must be removed on 4 cylinder engines
• The following describes removal and installation on a 2.0L TFSI vehicle. The procedure may be different on other 4 cylinder vehicles.
- Disconnect electrical connector - 3 - on Mass Air Flow (MAF) Sensor (G70).
- Open spring clips - 1 - and - 2 - and remove air guide hose from mass airflow sensor.
- Remove front air intake from lock carrier - 4 -.
- Remove engine cover.
Components, that must be removed on 5 cylinder vehicles
- Remove the air guide pipe (from the air filter to the turbocharger).
Components, that must be removed on 6 cylinder vehicles
• The following describes removal and installation on a 3.2L MPI vehicle. The procedure may be different on other 6 cylinder vehicles.
- Remove vacuum hose to brake booster - arrow -.
Components that must be loosened or removed on all vehicles
- Remove nuts- arrows -.
- If present, unclip line- A - from bracket.
- Remove remaining nuts- A -.
- Loosen heat shield - B - from mounting points (lay it aside or remove it completely).
- Remove bolts- A -.
- Disconnect refrigerant lines - B - and - C -.
• Seal open lines and the connections on the expansion valve with suitable caps (to prevent dirt and moisture from entering).
• After switching off the A/C compressor in this vehicle, it may take a relatively long time for the pressure on the high pressure side to decrease. This is because the expansion valve is cold and the pressure on the low pressure side increases quickly after shutting the compressor off, then the expansion valve closes and the refrigerant flows slowly to the low pressure side.
• In model year 2007, the hose piece in the refrigerant line on the high pressure side (thin line) - C - was discontinued as a running change. Bend a refrigerant line - C - carefully, and only as far as absolutely necessary to remove the expansion valve. If necessary, loosen a refrigerant line that has no flexible piece of tubing out of the bracket so that the refrigerant line does not get damaged.
Installing
• Tightening specification: Bolts - A - (Refrigerant line expansion valve mounting screws) - 10 Nm
Installation is carried out in the reverse order while noting the following:
- Replace O-ring seals - D - and - E -, version, refer to Electronic Parts Catalog (ETKA).
- Check fitted pin - G - (installed in connection or in expansion valve, not installed at all connections) and sleeve - H - for damage and proper seating.
• Coat the O-ring seals lightly with refrigerant oil prior to installation. Refer to=> [ Refrigerant Circuit O-rings ] Refrigerant Circuit O-rings.
• Check the O-rings for proper seating within the groove - F - on the refrigerant line.
• Install refrigerant pipes such that they are not strained.
• Depending on vehicle equipment and on engine, heat insulation has been applied to refrigerant lines, these must not be damaged and must be re-applied after installing.
• Check installation position of refrigerant lines to expansion valve (they must not contact other components) and position and state of heat protection insulation applied to refrigerant lines if necessary (not installed on all engine types).
- Discharge and fill the refrigerant circuit.
- Install remaining components.
- Operate the A/C system after filling the refrigerant circuit. Refer to=> [ A/C System, Operating After Filling Refrigerant Circuit ] A/C System, Operating After Filling Refrigerant Circuit.
• Note the information regarding operating the A/C system after filling.