Audi A4: Refrigerant Circuit, Flushing
Note
- In the case of vehicles on which the refrigerant lines have
no threads for connection of Adapter Set -1785-. Use for example
a flushing gun with rubber end piece or an adapter from the
Refrigerant Circuits Adapter Set 1 -VAS6338/1- for blowing
through the individual components. When using a flushing gun
with rubber end piece, take special care not to damage the
connections (crushing or scratching).
- Evaporator is to be flushed via the connection for
low-pressure pipe (large diameter) after removing expansion
valve or removing restrictor.
- Always clean (flush or blow) components in direction
opposite to refrigerant flow.
- Check expansion valve and replace if dirty or corroded.
- Locate any components on which dark, sticky deposits cannot
be removed with compressed air and either clean (flush) them
using refrigerant R134a or replace them.
- Thin, light grey deposits on the inside of pipes do not
impair the function of the components.
- After flushing, always replace receiver/dryer or reservoir
and restrictor. Replace the dryer cartridge on condensers that
have one installed in the integrated receiver/dryer.
- If the receiver/dryer or dryer cartridge is integrated in
the condenser, then they cannot be replaced separately and the
condenser must be replaced. Refer to the Parts Catalog and
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (vehicle-specific
repair manual).
- Receivers/dryers where it is possible to replace the dryer
cartridge have an additional filter, which must also be replaced
with the dryer cartridge.
After Blowing through the Refrigerant Circuit:
- Replace these components depending on equipment (restrictor
and reservoir, expansion valve and receiver/dryer or dryer
cartridge). Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (vehicle-specific
repair manual) and the Parts Catalog.
- Replace the A/C compressor, depending on its condition.
Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; A/C
Compressor (vehicle-specific repair manual) and Parts
Catalog or drain the rest of the refrigerant oil still inside
the removed A/C compressor (replace the refrigerant circuit
components) and will new refrigerant. Refer to
→ Chapter "Refrigerant Circuit Components, Replacing"
and
→ Chapter "Approved Refrigerant Oils and Capacities"
(Approved Refrigerant Oils and Capacities).
Note
- There is a defined and prescribed amount of refrigerant oil
in the replacement compressor. If the vehicle has two
evaporators, then there refrigerant circuit requires a specific
quantity of refrigerant oil. Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (vehicle-specific
repair manual) and
→ Chapter "Approved Refrigerant Oils and Capacities".
(Approved Refrigerant Oils and Capacities).
- If the A/C compressor is not be replaced, the quantity of
refrigerant oil in the A/C compressor must be topped off to the
prescribed capacity (tilt the refrigerant oil out and refill the
prescribed quantity into the A/C compressor or refrigerant
circuit). Refer to
→ Chapter "Refrigerant Circuit Components, Replacing"
(replacing refrigerant circuit components) and
→ Chapter "Approved Refrigerant Oils and Capacities".
Approved Refrigerant Oils and Capacities).
- Reassemble the refrigerant circuit completely. Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (vehicle-specific
repair manual).
- Evacuate and recharge the refrigerant circuit according to
specification. Refer to
→ Chapter "Refrigerant Circuit, Discharging with Service
Station" and
→ Chapter "Refrigerant Circuit, Charging with Service Station".
- Start up A/C system according to specification. Refer to
→ Heating, Ventilation and Air Conditioning; Rep.
Gr.87; Refrigerant Circuit; A/C System, Starting Operation after
Filling Refrigerant Circuit (vehicle-specific repair
manual) and
→ Chapter "A/C System, Operating after Charging".
READ NEXT:
Vehicles with a High Voltage System (Hybrid Vehicles)
Extremely Dangerous Due to High-Voltage
The high-voltage system is under high-voltage. Death or serious
bodily injury by electric shock.
- I
Note
The arrows in the following illustrations show the direction
of refrigerant flow during flushing (refrigerant flows in
opposite direction of flow when Air Conditioning (A/C) system is
SEE MORE:
Underbody Trim Panel, Removing and Installing, Front
Removing
- Remove the nuts -arrows-.
- Remove the front underbody trim panel -2-
from the center underbody trim panel -1-.
Installing
Install in reverse order of removal.
Tightening Specifications
Refer to
→ Chapter "Overview
USB adapter
Fig. 151 Audi Genuine Accessories: USB adapter
You can connect your mobile devices through the
Audi music interface to the MMI using the USB
adapter and charge the battery at the same time.
You can purchase the USB adapter cable from an
authorized Audi dealer or at specialty stores: