Audi A6 Typ 4G: Connections for Quick-Release Coupling on Refrigerant Circuit
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 pressure side.
- Discharge the refrigerant circuit before removing valves or
valve inserts.
- Always screw on sealing caps.
Allocation in the vehicle. Refer to
→ Heating, Ventilation and Air Conditioning; Rep. Gr.87; System
Overview - Refrigerant Circuit (vehicle-specific
repair manual).
WARNING
There is a danger of ice-up.
Refrigerant will leak out if refrigerant circuit is
not discharged.
Refrigerant must be extracted before opening
refrigerant circuit. If refrigerant circuit is not
opened within 10 minutes of extraction, pressure may
form in refrigerant circuit due to evaporation. Extract
the refrigerant once more.
Connections with Schrader Valve (Needle Valve)
- -A- Service connection
(soldered in)
- -B- valve insert (Schrader
valve or needle valve)
- -C- O-ring (belonging to the
valve)
- -D- cap with seal
Note
- After connecting, install the hand wheel for the service
coupling just far enough into the quick-release coupling adapter
until the valve is securely opened inside the service connection
(pay attention to the pressure gauge, do not put too much
pressure on the valve).
- For removing and installing the valve set
-B- when the refrigerant circuit is
evacuated, for example, use an adapter from the Refrigerant
Sockets -T10364-.
- Tighten the valve insert -B-
very carefully because the tightening specification is very
small.
- There are different versions of these valves and therefore
there are different tightening specifications. Valve insert
-B- with a VG5 (5.2 x 0.7 mm, tire
valve) thread has a tightening specification of 0.4 Nm +- 0.1 Nm;
a valve insert with a M6 x 0.75 mm thread has a tightening
specification of 0.9 Nm +- 0.1 Nm, and a valve insert with a M8 x
1.0 mm thread has a tightening specification of 2.0 Nm +- 0.2 Nm.
- There are different versions of these valves, valve inserts
and their respective sealing caps. Be sure to use the correct
valve version and the correct sealing cap allocation. Refer to
the Parts Catalog.
Connections with Primary Sealing Valve (Ball Valve)
WARNING
Before unscrewing the connection, connect the
service station and extract the refrigerant. Refrigerant
circuit must be empty to avoid possible injury.
Connection with High-Pressure Valve
1 - Socket with internal thread (soldered in)
2 - O-ring (version and identification: black or colored. Refer
to the Parts Catalog)
3 - Valve with an external thread and groove for the O-ring
(identification: ball valve)
4 - Cap seal
5 - Sealing cap
The service connection on the high pressure side depends on
the vehicle, not all operating conditions of the A/C system are
on high pressure (for example on the Audi Q7 e-tron). For this
reason to check the A/C function in these vehicles the sensor
installed in the refrigerant circuit must be used. Refer to
→ Heating, Ventilation and Air Conditioning; Rep.
Gr.87; Refrigerant Circuit and use the Vehicle
Diagnostic Tester in the "Guided Fault Finding" function.
Note
- After connecting, install the hand wheel for the service
coupling just far enough into the quick-release coupling adapter
until the valve is securely opened inside the service connection
(pay attention to the pressure gauge, do not put too much
pressure on the valve).
- For removing and installing the valve
-3- when the refrigerant circuit is evacuated, for
example, use an adapter from the Refrigerant Sockets -T10364-.
- There are different versions of these valves (with internal
or external threads). Therefore the tightening specifications
can also differ. The valves -3-
with an M12 x 1.5 mm external thread have a tightening
specification of 9 Nm +-1 Nm.
- There are different versions of these valves and their
respective caps. Be sure to use the correct valve version and
the correct sealing cap allocation. Refer to the Parts Catalog.
Connection with Low-Pressure Valve
1 - Socket with an external thread and groove for the o-ring
(soldered in)
2 - O-ring (version and identification: black or colored. Refer
to the Parts Catalog)
3 - Valve with an internal thread
4 - Cap seal
5 - Sealing cap
Note
- Install the hand wheel for the service coupling just far
enough into the quick-release coupling adapter until the valve
is securely opened inside the service connection (pay attention
to the pressure gauge, do not put too much pressure on the
valve).
- For removing and installing the valve
-3- when the refrigerant circuit is evacuated, for
example, use an adapter from the Refrigerant Sockets -T10364-.
- There are different versions of these valves (with internal
or external threads). Therefore the tightening specifications
can also differ. The currently used valves
-3- with an M10 x 1.25 mm internal thread have a
tightening specification of 9 Nm +- 1 Nm.
- There are different versions of these valves and their
respective caps. Be sure to use the correct valve version and
the correct sealing cap allocation. Refer to the Parts Catalog.
READ NEXT:
A/C Refrigerant High Pressure Switch -F23-
Note
Switch pressures, removing and installing switches as well
as switch arrangement and version. Refer to vehicle specific
refrigerant circuit
â
General Information
Caution
When performing work on refrigerant circuit, observe
all generally applicable safety precautions and pressure
container regulations.
The pressures and temperatur
General Information
Indicators on pressure gauge
1 - Temperature scale for refrigerant R134a CF3-CH2F or
CH2F-CF3.
2 - Pressure scale
Note
Pressure is measured in differen
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Weight distribution
Towing a loaded trailer with an empty car results
in a highly unstable distribution of weight. If this
cannot be avoided, drive at very low speeds only
to avoid the risk of losing steering control.
A "balanced"
Fig. 184 Engine compartment: coolant expansion tank
cover
Observe the safety precautions
in Working
in the engine compartment.
Checking the engine coolant level
Park the vehicle on a level surface.
Switch the ignition off.
Read the coolant level on the coolant expansion
tank
fig. 182. The coo