Audi Q3: Refrigerant Circuit, Tracing Leaks Using Electronic Leak Detector
Vehicles with a High Voltage System (Hybrid Vehicles)
Read and follow all of the supplemental warnings for all
work performed on vehicles with the high voltage system. Refer
to
→ Chapter "Warnings when Working on Vehicles with High Voltage
System" and
→ Electrical Equipment; Rep. Gr.93; General Warnings when
Working on High Voltage System.
All vehicles
Note
- The various refrigerants have differing molecular
compositions. The electronic leak detector sensors are set up to
detect these molecules. If an electronic leak detector is used,
which is not specifically designed to detect refrigerant R134a,
it will not respond to the refrigerant R134a or will only do so
when there is a larger concentration of R134a in the area of the
leak.
- Depending on the version of the A/C unit, an evaporator leak
can be determined either by holding the leak detector test probe
over the glove compartment cooling connection in the A/C unit,
or by holding the test probe on an open connection of a
disconnected A/C condensation water hose.
Perform a leak detection test to locate the leak while the
refrigerant circuit is completely empty:
Caution
To prevent more refrigerant than is necessary for
the leak test from venting into the air, proceed as
follows with the refrigerant circuit completely empty:
- Evacuate the refrigerant circuit with the A/C service
station. Refer to
→ Chapter "Refrigerant Circuit, Discharging with Service
Station".
Note
- If a larger leak is found during evacuation, find and it and
repair it as described. Refer to
→ Chapter "Refrigerant Circuit, Discharging with Service
Station".
- If no leak is found during evacuation or there is a leak
that is so small that the location cannot be found with the
vacuum test, proceed as follows.
- Fill the evacuated refrigerant circuit with approximately 100 grams of
refrigerant and perform the leak test in the same way as for a refrigerant
circuit that is filled with refrigerant.
Perform a leak detection test on a
refrigerant circuit that is filled with refrigerant:
- Turn off the ignition.
- Start up the leak detector in line with relevant operating
instructions.
- Always hold the test probe underneath the suspected leak.
Depending on the model, leak detection is indicated by an
increase in clicking rate or a warning tone. Refer to operating
instructions for leak detector.
Note
- Currents of air quickly disperse refrigerant gas. Draughts
must therefore be avoided during leak detection.
- Refrigerant gas is heavier than air and will escape.
Leak Detection on Refrigerant Circuit Using Leak Detection Kit
-VAS6201A-
Vehicles with a High Voltage System (Hybrid Vehicles)
Read and follow all of the supplemental warnings for all
work performed on vehicles with the high voltage system. Refer
to
→ Chapter "Warnings when Working on Vehicles with High Voltage
System" and
→ Electrical Equipment; Rep. Gr.93; General Warnings when
Working on High Voltage System.
All vehicles
Note
- Certain leaks cannot or only with difficulty be found using
an electric leak detection unit. Leak detection can be performed
using Leak Detection Kit -VAS6201A-.
- Refrigerant and refrigerant oil escape when there is a leak
in the refrigerant circuit. Generally, this oil remains in the
vicinity of the leaking area. A small amount of fluorescent
fluid must be added into refrigerant circuit so that this oil
becomes visible under UV light. This fluid (PAG oil with an
additive that lights up under UV light) is added into the
refrigerant circuit and distributes itself with the refrigerant
oil when the A/C system is switched on.
- A/C system must be operated for a minimum of 60 minutes so
that the additive distributes itself in the entire refrigerant
circuit (compressor must be running). Depending on the size of
the leak, it may become visible under UV light within that time.
- Refrigerant oil with additive that lights up under UV-light
can be added directly with an open circuit or be pumped into a
filled circuit via service connection on the low pressure side
using Leak Detection Kit - Hand Pump w/Cartridge -VAS6201/1-
(from Leak Detection Kit -VAS6201A-).
- If the UV-leak detection additive is added to a filled
refrigerant circuit via the service connection on the low
pressure side, a small amount of it remains in the service
connection. Carefully remove this residual amount so that a
leaking area is not detected erroneously upon a later leak
detection.
- If a component in which UV-leak detection additive has been
added is being replaced on a circuit, thoroughly clean the
connection areas to the other components after assembling the
refrigerant circuit. The UV-leak detection additive residue may
register erroneously as leaking areas during later leak
detection.
- Refrigerant oil as well as UV-leak detection additive get
into the service station when evacuating a refrigerant circuit.
The refrigerant oil is separated from refrigerant in oil
collector of service station and removed from the service
station via the draining device. The refrigerant oil drained off
must not be poured back in. It must be replaced with new
refrigerant oil.
- If leak detection fluid was filled already in a refrigerant
circuit for an earlier repair, note the following: Only add new
leak detection fluid if the refrigerant oil will be replaced. If
only a portion of refrigerant oil was replaced, only top-off
with a corresponding amount of leak detection fluid as well. For
example, if 100 ml of refrigerant oil was replaced in a vehicle
with 250 ml, add only 1 ml (cm3) of
UV-leak detection additive.
- Certain materials and their connections (for example,
oxidation products on aluminum components, corrosion protection
growth, etc.) also light up under UV-light.
- Depending on the version of the A/C service station, UV-leak
detection additive can also be added directly at the top. Refer
to the operating instructions that come with the A/C service
station.
To prevent more refrigerant than is necessary for the leak
test from venting into the air, proceed as follows with the
refrigerant circuit completely empty:
- Evacuate the refrigerant circuit with the A/C service
station. Refer to
→ Chapter "Refrigerant Circuit, Discharging with Service
Station".
Note
- If a larger leak is found during evacuation, find and repair
it as described. Refer to
→ Chapter "Finding Leaks via Vacuum Test using A/C Service
Station or Nitrogen Pressure Testing" and
→ Chapter "Refrigerant Circuit, Discharging with Service
Station".
- The UV-leak detection additive can also be filled in a filled or open
refrigerant circuit with the Leak Detection Kit -VAS6201A-.
- If no leak is found during evacuation or there is a leak
that is so small that the location cannot be found, proceed as
follows.
- Add the UV-leak detection additive using the A/C service station to
the refrigerant circuit.
- Add UV-leak detection additive using the Leak Detection Kit -VAS6201-
in the refrigerant circuit.
Add the UV-leak detection additive
using the A/C service station to the refrigerant circuit.
- Add the UV-leak detection additive and the prescribed
refrigerant amount using the A/C Service Station to the
refrigerant circuit. Refer to
→ Chapter "Refrigerant R134a Capacities".
Note
Add 2.5 +- 0.5 cm3 of UV-leak
detection additive for a refrigerant circuit with a refrigerant
capacity of 100 to 150 cm 3 with the
Leak Detection Kit -VAS6201- for the Leak Detection Kit
-VAS6201-. If the refrigerant oil capacity in the refrigerant
circuit is larger, then more UV leak detection additive must be
added accordingly (for example, 5.0 +- 0.5 cm3
for a refrigerant circuit with a refrigerant oil capacity of 250
cm 3. When adding the UV-leak
detection additive using the A/C service station, consult the
corresponding Owner's Manual as the required amount may vary.
For the relevant refrigerant oil quantities in the refrigerant
circuit. Refer to
→ Chapter "Approved Refrigerant Oils and Capacities".
Special tools and workshop equipment
required
- A/C service station with the option for adding the UV-leak
detection additive to the refrigerant circuit. Refer to the
Parts Catalog (Tools; Special Tools and Equipment: A/C and
Heating).
- Approved leak detection additive. Refer to the Parts Catalog
(Tools; Special Tools and Equipment: A/C and Heating).
- Leak Detection Kit - Cleaning Solution -VAS6201/3--3-
- UV Leak Detection Lamp -VAS6201/4A--4-
- Leak Detection Kit - Eye Protection -VAS6201/6--5-
- Leak Detection Kit - Label -VAS6201/7--6-
- Apply a label near the service connection stating that
UV-leak detection additive was added to the refrigerant circuit.
- Start the A/C system.
Note
- A/C system must be operated for a minimum of 60 minutes so
that the additive distributes itself in the entire refrigerant
circuit (compressor must be running). Depending on the size of
the leak, it may become visible under UV light within that time.
- Depending on the size and location of the leak, it can now
last up to several days until enough refrigerant oil with
UV-leak detection additive flows out to clearly determine the
leaking area.
- Find the leak in the refrigerant circuit with the UV Lamp -VAS6196/4-.
Add UV-leak detection additive using
the Leak Detection Kit -VAS6201- in the refrigerant circuit
Special tools and workshop equipment
required
- Leak Detection Kit -VAS6201A-
The Leak Detection Kit -VAS6201A- includes the following
tools. Refer to the Parts Catalog (Tools; Special Tools and
Equipment: A/C and Heating).
1 - Leak Detection Kit - Hand Pump w/Cartridge -VAS6201/1-
2 - Leak Detection Kit - Cartridge -VAS6201/2- (with UV-leak
detection additive)
3 - Leak Detection Kit - Cleaning Solution -VAS6201/3-
4 - UV Leak Detection Lamp -VAS6201/4A-
5 - Leak Detection Kit - Eye Protection -VAS6201/6-
6 - Leak Detection Kit - Label -VAS6201/7-
7 - Leak Detection Kit - Filler Tube
-VAS6201/8-
8 - Leak Detection Kit - Hand Protection -VAS6201/9-
Note
- Described in the following are instructions for how to pour
the UV-leak detection additive into the refrigerant circuit
using the Leak Detection Kit -VAS6201A-. If the UV-leak
detection additive is added to the refrigerant circuit with the
help of other tools (for example, with the A/C service station)
read the applicable operating instructions.
- The following is the given amount of UV-leak detection
additive that is to be added to a refrigerant circuit with a
refrigerant oil quantity of 100 to 150 cm 3 using the Leak Detection Kit -VAS6201A- (2.5 +- 0.5 cm3).
If the refrigerant oil capacity in the refrigerant circuit is
larger, then more UV leak detection additive must be added
accordingly (for example, 5.0 +- 0.5 cm3
for a refrigerant circuit with a refrigerant oil capacity of 250
cm 3. For the relevant refrigerant
oil quantities in the refrigerant circuit. Refer to
→ Chapter "Approved Refrigerant Oils and Capacities".
- If the UV-leak detection additive is added to the
refrigerant circuit with the help of other tools (for example,
with the A/C service station), observe the prescribed quantities
of UV-leak detection additive given in the corresponding
operating instructions.
Adding UV-leak detection additive
when the refrigerant circuit is empty
The cartridge -A- contains 15.4
ml of UV-leak detection additive (one unit
-B- corresponds to 2.5 ml).
- Assemble the Leak Detection Kit -VAS6201A--1-
with the cartridge -2-Leak
Detection Kit - Cartridge -VAS6201/2-.
- Insert the Leak Detection Kit - Filler Tube -VAS6201/8-.
Refer -item 7- into
the hand pump.
- Open the hand pump service valve.
Note
- UV-Leak detection additive is best added to the empty
refrigerant circuit via a service connection or an opened
connection.
- If the refrigerant circuit is empty, then it is better to
add the UV-leak detection additive via a connection point (for
example, when the connection point is already open). This way no
UV-leak detection additive remains in the service connection and
the connection does not need to cleaned.
- Add the UV-leak detection additive to the refrigerant circuit via a
service connection.
- Add the UV-leak detection additive to the refrigerant circuit via an
opened connection.
Add the UV-leak detection additive to
the refrigerant circuit via an opened connection
- Open an easily accessible connection point on the
refrigerant circuit
- Cover the area around connection point with foil or
absorbent paper.
- Hold the tube upwards.
- Tighten the hand pump handle just enough until the UV-leak
detection additive comes out of the tube.
- Add 2.5 +- 0.5 ml (Milliliter = cm3)
of UV-leak detection additive to the refrigerant circuit (for a
refrigerant circuit with a refrigerant oil capacity from 100 to
150 cm3).
Note
If UV-leak detection additive was already added to the
refrigerant circuit for an earlier repair, note the following:
Only add new UV-leak detection additive if the refrigerant oil
will be replaced. If only a portion of the refrigerant oil was
replaced, only add a proportionate amount of the UV-leak
detection additive. For example, if 100 ml of refrigerant oil
was replaced in a vehicle with 250 ml, add only 2 ml (cm3)
of UV-leak detection additive.
- Replace the O-ring seal at the opened connection point.
- Assemble the refrigerant circuit.
- Apply a label near the service connection stating that leak
detection fluid was added to the refrigerant circuit.
- 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 the A/C system.
Note
- A/C system must be operated for a minimum of 60 minutes so
that the additive distributes itself in the entire refrigerant
circuit (compressor must be running). Depending on the size of
the leak, it may become visible under UV light within that time.
- Depending on the size and location of the leak, it can now
last up to several days until enough refrigerant oil with
additive flows out to determine definitely the leaking area.
- Find the leak in the refrigerant circuit with the UV Lamp -VAS6196/4-.
Adding UV-leak detection additive when
the refrigerant circuit is full
Note
- If leak detection fluid was filled already in a refrigerant
circuit for an earlier repair, note the following: Only add new
leak detection fluid if the refrigerant oil will be replaced. If
only a portion of refrigerant oil was replaced, only top-off
with a corresponding amount of leak detection fluid as well. For
example, if 100 ml of refrigerant oil was replaced in a vehicle
with 250 ml, add only 1 ml (cm3) of
UV-leak detection additive.
- A small quantity of UV-leak detection additive remains in
the service connection. Carefully remove this residual amount so
that a leaking area is not detected erroneously upon a later
leak detection.
The cartridge -A- contains 15.4
ml of UV-leak detection additive (one unit
-B- corresponds to 2.5 ml).
- Switch off ignition.
- Remove sealing cap from service connection of low pressure
side in refrigerant circuit.
- Assemble the Leak Detection Kit -VAS6201A--1-
with the cartridge -2-Leak
Detection Kit - Cartridge -VAS6201/2-.
- Insert Leak Detection Kit - Filler Tube -VAS6201/8--7-into
service coupling and open service coupling by screwing in
hand wheel. Hold the hose upward and tighten the handle
of the hand pump just enough until the UV-leak detection
additive starts to emerge from the tube.
Note
Make sure hand pump hose is completely filled with
refrigerant.
- Close the service coupling and remove tube from the
retainer.
- Cover the area around the service connection on the vehicle
with foil or absorbent paper.
- Connect the filler device to the refrigerant circuit service
connection on the vehicle.
- Open the service connection by screwing in the hand wheel.
- Turn the hand pump handle to add 2.5 +- 0.5 ml (Milliliter =
cm3) UV-leak detection additive to
the refrigerant circuit (for a refrigerant circuit with a
refrigerant oil quantity from 100 to 150 cm3).
- Remove the filling device from the service connection.
- Remove the rest of the UV-leak detection additive from the
service connection, for example using absorbent paper.
- Seal the service connection with the sealing cap.
- If necessary, clean the area around service connection using
cleaning solution.
- Apply a label near the service connection stating that leak
detection fluid was added to the refrigerant circuit.
- Start the A/C system.
Note
- A/C system must be operated for a minimum of 60 minutes so
that the additive distributes itself in the entire refrigerant
circuit (compressor must be running). Depending on the size of
the leak, it may become visible under UV light within that time.
- Depending on the size and location of the leak, it can now
last up to several days until enough refrigerant oil with
additive flows out to determine definitely the leaking area.
- Find the leak in the refrigerant circuit with the UV Lamp -VAS6196/4-.
Detecting leaks on the refrigerant
circuit using UV Lamp -VAS6196/4-
WARNING
Do not look into UV lamp.
Do not direct UV lamp at other people.
Note
- After adding the UV-leak detection additive, the A/C system
must be operated for a minimum of 60 minutes so that the
additive distributes itself in the entire refrigerant circuit
(compressor must be running). Depending on the size of the leak,
it may become visible under UV light within that time.
- Depending on the size and location of the leak, it can now
last up to several days until enough refrigerant oil with
additive flows out to determine definitely the leaking area.
- With leaks on the evaporator, leak detection additive is
possibly washed off with condensation and flows out via
evaporator drain. Since the evaporator is not easily accessible
on most vehicles, checking the evaporator drain may indicate if
the evaporator is leaking. However, it is necessary for this
purpose that leak detection additive has already been in the
refrigerant circuit for a long period of time (for example, a
few days).
- The protective goggles do not only serve as eye protection
but also amplify the illumination of leak detection additive
under UV light.
- Depending on the accessibility of different components in
the refrigerant circuit, it may be necessary to remove some
vehicle components such as the bumper or air filter.
- Only a little refrigerant oil will get onto certain places
on the refrigerant circuit when A/C is being used (for example,
on the top cover of the receiver/dryer attached to the condenser
on an Audi A8 from MY 2010). If there is a leak at this spot, it
may take longer until enough refrigerant with refrigerant oil
and additive start to leak out, which then can be viewed under
UV light. It may be useful to use an electronic leak detector at
these locations to find a leak. Refer to
→ Chapter "Refrigerant Circuit, Tracing Leaks Using Electronic
Leak Detector".
- Move vehicle into a slightly darker area of the workshop
(with daylight or bright lighting the effect of the UV light is
diminished).
- Check the accessibility of the various components in the
refrigerant circuit and remove any components in the area that
block access to the refrigerant circuit such as noise insulation
and the bumper.
- Wear protective eyewear to protect the eyes.
- Connect the UV-lamp to a 12 volt battery (vehicle battery).
Observe the correct polarity of connections.
- Switch on the UV lamp and illuminate the components of
refrigerant circuit. Locations where refrigerant, refrigerant
oil and UV-leak detection additive has leaked out light up under
fluorescent UV light.
Finding Leaks via Vacuum Test using A/C Service Station or Nitrogen
Pressure Testing
Vehicles with a High Voltage System (Hybrid Vehicles)
Read and follow all of the supplemental warnings for all
work performed on vehicles with the high voltage system. Refer
to
→ Chapter "Warnings when Working on Vehicles with High Voltage
System" and
→ Electrical Equipment; Rep. Gr.93; General Warnings when
Working on High Voltage System.
All vehicles
- Turn off the ignition.
- For finding leaks via the vacuum test using the A/C service
station or nitrogen pressure testing. Refer to
→ Chapter "Refrigerant Circuit, Discharging with Service
Station".
Note
- Small leaks (less than 100 g of refrigerant loss per year)
are not often detected with the vacuum test or with the nitrogen
pressure test. The incoming air and the amount of nitrogen
flowing out is too small to be able to locate the faulty
location based on noise.
- Leaks on the refrigerant circuit that are greater than 100 g
of refrigerant loss each year are also not always detectable
with the vacuum test or with the nitrogen pressure test,
depending on the ambient conditions (ambient noise, leak
location etc.). The incoming air and the quantity of nitrogen
flowing out is currently too small to detect any noise and
locate the faulty location.
- Larger leaks on the refrigerant circuit (for example, an
impact from a rock on the condenser, refrigerant loss greater
than 100 g per year) can be detected, for example by noise,
using the vacuum test or the nitrogen pressure test. Refer to
→ Chapter "Refrigerant Circuit, Discharging with Service
Station".
READ NEXT:
Possible Refrigerant Circuit Concerns
Test Requirements
Electrical Equipment, vacuum system and air duct
fault-finding has not revealed any faults. Refer to Guided Fault
Finding for the A/C s
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.
-&nb
SEE MORE:
A - Wet braking behavior
B - Comfort
C - Steering precision
D - Driving stability
E - Tire weight
F - Service life expectancy
G - Rolling resistance
H - Hydroplaning
The pie chart represents the tire's performa
The refrigerant circuit was completely empty (for example
with larger leak or cracked hose)
Note
In the event of only a minor leak with slow escape of
refrigerant (e.g. at a small leakage point), the amount of
refrigerant oil lost and the amount of moisture penetrating is
not s