Audi A4: Quick-Release Connections on Refrigerant Lines
WARNING
The quick-release coupling connectors may be
unlocked and opened only if the refrigerant circuit is
empty.
Note
- This illustration shows the quick-coupling connection with a
refrigerant pipe with an inner heat exchanger that is installed
in the Audi A4 from MY 2008 and on the Audi A5 Coupe from MY
2008. Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (vehicle-specific
repair manual).
- The retaining ring -A- must be
opened using, for example, the Air Conditioner Couplings Release
Tool -T40149- in order to remove the refrigerant line
-D-. Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (vehicle-specific
repair manual).
- The quick-release coupling connectors
-B- and -G- are to be
replaced after removing the refrigerant line with the respective
support ring -E- or
-H- and O-ring
-F- or -J-.
Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (vehicle-specific
repair manual) and the Parts Catalog).
A - Retaining ring (inside the quick-release coupling connector,
high pressure side)
B - Quick-release coupling connector with retaining ring "high pressure side"
C - Refrigerant line with an inner heat exchanger
D - Refrigerant line "high pressure side"
E - Support ring "high pressure side"
F - O-ring "high pressure side"
G - Quick-release coupling connector with retaining ring "low pressure side"
H - Support ring "low pressure side"
J - O-ring "low pressure side"
Note
- There are different quick-release coupling versions
-A- and -D-.
The refrigerant lines -C-, for
example, can unlocked and removed using the Air Conditioner
Couplings Release Tool -T40149/1- in the same manner for both
versions of the quick-release couplings.
- The check pins on the -B-
quick-release couplings -A-
installed at SOP are visible -C-,
when the locked refrigerant line -C-
is pulled in the direction of arrow.
- Beginning with MY 2010, as a running change, the
quick-release coupling -D- and the
refrigerant line -C- are being
installed in the same manner as the quick-release coupling
-A-. If the refrigerant line
-C- is pulled in the direction of
arrow after assembling, the ring -E-
will come out of the quick-release coupling
-D- installed and will show that
the retaining ring -F- is
completely latched to the refrigerant line
-C-. Then the ring -E- can
be removed from the refrigerant line -C-.
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.
READ NEXT:
Refrigerant Circuit with Expansion Valve and Evaporator
The following illustration shows only the principle of a
refrigerant circuit, the design of the refrigerant circuit in
the respective vehicle
General Information
Only valves and connections that are resistant to
refrigerant R134a and refrigerant oil must be installed.
Different connections (outer diameter) for high pressure and
low pre
SEE MORE:
Overview - Headliner
Overview - Headliner, Sedan
1 - Headliner
Removing and installing. Refer to
→ Chapter "Headliner, Removing and Installing, Sedan".
2 - Clip
For vehicles with sliding sunroof
Quantity: 15
Insert in the headliner
Replace damaged or deformed cli
Removing
- Move the front seats all the way forward.
- Unclip the child seat anchor guides (quantity: four)
-1- from anchorages. Refer to
→ Chapter "Lower Child Seat Anchor Guide, Removing and
Installing".
- With both hands, grasp the bench seat -1-
under the seat frame -2-.