Expansion Valve

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. If the A/C compressor is switched on, the pressure on the low pressure side goes down, the expansion valve open and the refrigerant can flow of the low pressure side.

• From the start of production through the change-over from MY 12, evaporators approximately 40 mm (1.6 in.) wide (block depth) - A - are being installed (air conditioner part number "8K_ 820 005"). From MY 12, as a running change and depending on the version of the vehicle, an approximately 50 mm (2 in.) wide evaporator (block depth) - A - is being installed (air conditioner part number "8T_ 820 005"). Pay attention to the correct allocation of the evaporator expansion valve (there are different versions). Refer to the Parts Catalog.






• There is a label - A - on the outside of the A/C unit with a part - B - that tells which version is installed. Refer to Electronic Parts Catalog (ETKA).






• The part number - B - on the decal - A - can be read when the CD changer is removed (depending on the vehicle equipment level). Refer to Electronic Parts Catalog (ETKA).

- Turn off the ignition.

- Drain the refrigerant circuit.

• Depending on the allocation of the service connection an on the refrigerant line, and on the version of the vehicle, it may be necessary to remove the additional reinforcement on the left suspension strut dome so that the service coupling of the service station can be connected (for example, on the Audi Q5).


- Disconnect the ground cable from the battery (A).

- Remove the refrigerant line with inner heat exchanger. Refer to => [ Refrigerant Circuit Components ] Refrigerant Circuit Components.

• It may be necessary to remove the cowl panel - C - in order to remove and install the expansion valve.

For vehicles without a high voltage system

- Disconnect the ground cable from the battery (A).

- Remove the plenum chamber cover and/or the cowl panel (there are different versions).

All vehicles

- Loosen the refrigerant line with inner heat exchanger from the expansion valve and lay it to the side (do not remove). Refer to => [ Refrigerant Circuit Components ] Refrigerant Circuit Components.

• The plenum chamber front wall cannot be loosened or removed from the vehicle (there is not enough space available).

• When loosening the plenum chamber front wall, be careful not to damage the brake booster vacuum line.

All vehicles

- Remove screws - A -.






- Disconnect the expansion valve - B - from the refrigerant lines leading to the evaporator.

• Seal all open lines and connections on evaporator with suitable caps (avoid dirt and moisture from entering the system).

Installing






Installation is done is reverse order, observe the following:

- Clean the connection pipes - C - and - E - leading to the evaporator and the expansion valve connections, and check for damage.

• Expansion valve is available in different versions (same housing but a different control characteristic), therefore ensure the exact allocation. Refer to Electronic Parts Catalog (ETKA).

• Follow the instructions for installing the O-rings. Refer to => [ Refrigerant Circuit O-rings ] Refrigerant Circuit O-Rings.

- Replace the O-rings - B - and - F -. Refer to the Parts Catalog.

- Coat the O-ring seals with refrigerant oil prior to installation. Refer to => [ Refrigerant Circuit O-rings ] Refrigerant Circuit O-Rings.

- Make sure the retaining plate - D - fits correctly on the connection pipes - C - and - E - leading to the evaporator.

- Tighten the screws - G -.

• Tightening specification: 10 Nm.

- Install the refrigerant line with inner heat exchanger. Refer to => [ Refrigerant Circuit Components ] Refrigerant Circuit Components.

- Evacuate and fill the refrigerant circuit.


All vehicles

- Install the remaining removed components.

- Switch on the ignition.

- Check the Climatronic control module (J255) DTC memory and erase any displayed malfunctions if necessary. Refer to the Vehicle diagnostic tester in "Guided Fault Finding".

- 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.