Get Refrigerant circuit -> Tracing leaks in refrigerant circuit Guide for Audi A2 SUV 1999-2005

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

Note

♦ The refrigerant circuit is flushed in 4 operations (flushing cy‐

cles) on the Audi e-tron ⇒ Heating, air conditioning; Rep. gr.

87 ; Refrigerant circuit; Cleaning air conditioner refrigerant cir‐

cuit .

♦ To flush the entire refrigerant circuit on the Audi e-tron, it is not

merely sufficient for the installed shut-off valves to be in the

correct position (open or closed); the electrically activated

valves (in the valve block) must also be in the correct position.

The electrical valves are activated via different routines stored

in the corresponding control unit (e.g. in the thermal manage‐

ment control unit - J1024- ) ⇒ Heating, air conditioning; Rep.

gr. 87 ; Refrigerant circuit; Cleaning air conditioner refrigerant

circuit .

♦ To perform the flushing procedure on the Audi e-tron, the cir‐

cuit is separated into multiple sections, which are then flushed

in one flushing cycle each. The circuit is separated by activa‐

tion of the electrically activated valves and via the manual

shut-off valves (must be activated manually) ⇒ Heating, air

conditioning; Rep. gr. 87 ; Refrigerant circuit; Cleaning air

conditioner refrigerant circuit , ⇒ Vehicle diagnostic tester

(“Guided Fault Finding”).

♦ The layout of the different flushing circuits for the Audi e-tron

is described in the vehicle-specific Workshop Manual ⇒ Heat‐

ing, air conditioning; Rep. gr. 87 ; Refrigerant circuit; Cleaning

air conditioner refrigerant circuit .

♦ On vehicles with condensers with an integrated receiver / des‐

iccant cartridge which cannot be renewed separately or which

are not available as separate replacement parts, the condens‐

er must be renewed (together with integrated desiccant car‐

tridge) after flushing ⇒ Heating, air conditioning; Rep. gr. 87 ;

Refrigerant circuit (vehicle-specific Workshop Manual) and ⇒

Electronic parts catalogue .

♦ After flushing, the refrigerant receiver at the heat exchanger

for heat pump operation must be renewed ⇒ Heating, air con‐

ditioning; Rep. gr. 87 ; Refrigerant circuit .

♦ After flushing, the refrigerant shut-off valve - V424- must be

renewed ⇒ Heating, air conditioning; Rep. gr. 87 ; Refrigerant

circuit .

5.6

Tracing leaks in refrigerant circuit

Vehicles with high-voltage system (hybrid vehicles)

High voltage! Danger to life!

The voltage levels in the high-voltage system constitute a safety

hazard. Danger of severe or fatal injuries from electric shock.

– Persons with life-sustaining or other electronic medical devi‐

ces in or on their body must not perform any work on the high-

voltage system. Such medical devices include internal anal‐

gesic pumps, implanted defibrillators, pacemakers, insulin

pumps and hearing aids.

– The high-voltage system must be de-energised by a suitably

qualified person.

5. Refrigerant circuit

169

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

Risk of injury - engine may start unexpectedly

It is difficult to determine whether the drive system of an electric

vehicle or hybrid vehicle is active. Moving parts can trap or draw

in parts of the body.

– Switch off ignition.

– Place ignition key outside vehicle.

Risk of damage to high-voltage wiring

Incorrect handling may result in damage to the insulation of high-

voltage wires or high-voltage connectors.

– Never use high-voltage wiring or high-voltage connectors as

a support.

– Never prop tools against high-voltage wiring or high-voltage

connectors.

– Never bend or kink high-voltage wiring.

– Pay attention to coding when connecting high-voltage con‐

nections.

♦ For all work on vehicles with high-voltage system, note addi‐

tional warnings for working on such vehicles

⇒ “1 Warning instructions when working on vehicles with high-

voltage system”, page 1 .

♦ If work near high-voltage system components is necessary,

perform a visual check of the high-voltage components and

wires to check for damage ⇒ page 2 .

♦ If work on high-voltage system components is necessary, de-

energise high-voltage system ⇒ Rep. gr. 93 ; De-energising

high-voltage system or ⇒ Electrical system; Rep. gr. 93 ; De-

energising high-voltage system .

Note

The leak detection work at the refrigerant circuit using an elec‐

tronic leak detector or a UV leak detector lamp can usually also

be performed on the components of the high-voltage system with‐

out having to de-energise the high-voltage system.

– To minimise the number of automatic engine starts when the

vehicle's drive system is active during test and measurement

work, charge the vehicle batteries e.g. with the battery

charger 60A - VAS 5904- in battery standby mode ⇒ Electrical

system; General information; Rep. gr. 27 ; Battery; Charging

battery and ⇒ Electrical system; Rep. gr. 93 ; General warning

instructions for work on the high-voltage system .

– For test and measurement work that requires the vehicle's

drive system to be active (READY) or the ignition to be switch‐

ed on, move the selector lever to position “P”, activate the

parking brake and take care to keep well clear of the engine

when it is running. Set up any tools needed so that they cannot

come into contact with moving parts.

170

Rep. gr.87 - Air conditioning system

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

Note

♦ Move the selector lever to position “P” and activate the parking

brake before performing test and measurement work for which

the ignition must be switched on but where the vehicle's drive

system does not need to be active.

♦ The status of the drive system (READY) is shown by the con‐

trol unit in dash panel insert - J285- via the “power meter” ⇒

Owner's Manual .

♦ Activating and deactivating drive system ⇒ Owner's Manual

(note display of control unit in dash panel insert - J285- ).

Vehicles with start/stop system

Risk of injury - engine may start unexpectedly

The engine can start unexpectedly if the vehicle's start/stop sys‐

tem is activated. A message in the instrument cluster indicates

whether the start/stop system is activated.

– To deactivate the start/stop system, switch off the ignition.

All vehicles

WARNING

Risk of injury (frostbite).

Refrigerant may escape if the refrigerant circuit has not been

discharged.

Note

♦ Minor leaks can be detected with e.g. an electronic leak de‐

tector or UV leak detection lamp.

♦ This Workshop Manual describes two ways of tracing leaks in

refrigerant circuits. These procedures have been tested and

lead to a reliable result under the different usage conditions if

they are performed correctly and in accordance with the spe‐

cific complaint.

♦ Numerous systems are available on the market for the detec‐

tion of refrigerant circuit leaks. Not all of these yield unequiv‐

ocal results and, if not employed in the specified manner, may

indicate leaks at various refrigerant circuit components al‐

though these are actually intact. In addition, certain proce‐

dures can lead to damage to components of refrigerant

circuits.

♦ Do not service components that have been identified as leak‐

ing; they must always be renewed.

♦ Leaking refrigerant circuits are not to be filled with refrigerant.

Empty refrigerant circuits are therefore to be evacuated before

filling with refrigerant and checked for leaks in this process

⇒ page 86 .

5. Refrigerant circuit

171

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

Caution

♦ Audi objects to the use of chemical substances (sealing

additives) for sealing leaks in refrigerant circuits.

♦ Chemical substances for sealing leaks form deposits in

the refrigerant circuit which will impair operation of the air

conditioning system and lead to failure of the system (and

of the air conditioner service station).

Note

Chemical substances (sealing additives) for sealing leaks in the

refrigerant circuit generally react with the ambient air or the hu‐

midity contained in it. They cause malfunctioning of valves and

other components with which they come into contact on account

of deposits in the refrigerant circuit (and in the air conditioner

service station being used). These deposits cannot be completely

removed from the components affected (even by flushing). There‐

fore the refrigerant circuit can only be serviced by renewing all

components that have come into contact with the chemical sub‐

stances.

⇒ “5.6.1 Tracing leaks in refrigerant circuit using electronic leak

detector (e.g. V.A.G 1796)”, page 172

⇒ “5.6.2 Tracing leaks in refrigerant circuit with leak detection

system VAS 6201”, page 173

⇒ “5.6.3 Locating leaks using vacuum test with air conditioner

service station or nitrogen pressure test”, page 183

5.6.1

Tracing leaks in refrigerant circuit using

electronic leak detector (e.g. V.A.G

1796)

Vehicles with high-voltage system (hybrid vehicles)

For all work on vehicles with a high-voltage system, note the ad‐

ditional warning instructions for working on such vehicles

⇒ “1 Warning instructions when working on vehicles with high-

voltage system”, page 1 and ⇒ Electrical system; Rep. gr. 93 ;

General warning instructions for work on the high-voltage sys‐

tem .

All vehicles

Note

♦ The various refrigerants have a different molecular structure.

The sensors of the electronic leak detectors are matched to

these molecules. If use is made of an electronic leak detector

not specially designed for refrigerant R134a, this will not re‐

spond to refrigerant R134a or only in the event of a high

refrigerant concentration in the vicinity of the leak.

♦ Depending on the design of the air conditioning unit it may be

possible to determine a leak at the evaporator by inserting the

test prod of the leak detector through the connection for glove

compartment cooling into the air conditioning unit or - with the

condensation drain hose detached - by holding the test prod

at the open connection for the condensation drain of the air

conditioning unit.

172

Rep. gr.87 - Air conditioning system

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

Leak detection procedure for a refrigerant circuit completely emp‐

ty as a result of leakage:

Caution

Proceed as follows with a completely empty refrigerant circuit

to avoid allowing more refrigerant than is absolutely necessary

for leak detection to escape into the environment:

– Evacuate the refrigerant circuit using the air conditioner serv‐

ice station ⇒ page 86 .

Note

♦ If evacuation already reveals a major leak, this is to be located

and eliminated as described ⇒ page 86 .

♦ Continue as follows if evacuation does not reveal any leakage

or if the leakage is so slight that it is not possible to determine

the leakage location with the vacuum test.

– Pour roughly 100 g of refrigerant into the evacuated refrigerant

circuit and perform leak detection as for a refrigerant circuit

charged with refrigerant ⇒ page 173 .

Performing a leak test on a refrigerant circuit charged with refrig‐

erant:

– On vehicles with high-voltage system, switch off (deactivate)

auxiliary air conditioner function ⇒ Owner's Manual and ⇒

Infotainment/MMI Operating Manual .

– Switch off ignition.

– Start up leak detector in line with relevant operating instruc‐

tions.

– Always hold tip of test probe beneath suspected leak.

If clicking rate increases or a warning tone sounds (depends on

model), this indicates that the leak has been located (refer to op‐

erating instructions for leak detector).

Note

♦ Refrigerant gas is quickly dispersed by movement of air.

Draughts must therefore be avoided during leak detection.

♦ Refrigerant gas is heavier than air and therefore sinks to a

lower level at the exit location.

5.6.2

Tracing leaks in refrigerant circuit with

leak detection system VAS 6201

Vehicles with high-voltage system (hybrid vehicles)

For all work on vehicles with a high-voltage system, note the ad‐

ditional warning instructions for working on such vehicles

⇒ “1 Warning instructions when working on vehicles with high-

voltage system”, page 1 and ⇒ Electrical system; Rep. gr. 93 ;

General warning instructions for work on the high-voltage sys‐

tem .

5. Refrigerant circuit

173

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

All vehicles

Note

♦ Certain leaks are difficult or even impossible to find using an

electronic leak detector. In such cases, the leak detection sys‐

tem VAS 6201 can be used.

♦ Refrigerant circuit leaks result in a loss of refrigerant oil to‐

gether with the refrigerant. This oil generally remains in the

vicinity of the leak location. Adding a small quantity of fluores‐

cent fluid to the refrigerant circuit makes this oil visible under

UV light. The fluid (PAG oil containing an additive which shows

up under UV light) is poured into the refrigerant circuit and is

distributed with the refrigerant oil when the air conditioner is

switched on.

♦ The air conditioner must be operated for at least 60 min. to

distribute the additive through the entire refrigerant circuit (the

air conditioner compressor must be running). Depending on

the extent of the leak, the leakage location may already be‐

come visible under UV light within this period.

♦ The refrigerant oil containing the additive (which shows up un‐

der UV light) can either be poured directly into the open circuit

or pumped in with the circuit charged using the hand pump

VAS 6201/1 (from the leak detection system VAS 6201) via

the service connection on the low-pressure end.

♦ If the UV leak detection additive is applied via the service con‐

nection on the low-pressure end with the refrigerant circuit

charged, a small quantity of UV leak detection additive re‐

mains in the service connection. This is to be carefully re‐

moved so as to avoid subsequent erroneous leak detection.

♦ If a component forming part of a circuit, into which the UV leak

detection additive has been poured, has to be renewed, thor‐

oughly clean joints with other components after assembling

refrigerant circuit. Otherwise, the residual UV leak detection

additive at the joint could be erroneously identified as a leak‐

age location during subsequent leak localisation.

♦ On discharging the refrigerant circuit, refrigerant oil and thus

also UV leak detection additive ingresses into the air condi‐

tioner service station. The refrigerant oil is removed from the

refrigerant in the oil separator of the air conditioner service

station and discharged from the air conditioner service station

via the drain. Do not pour the refrigerant oil drained off back

in. It must be replaced with fresh refrigerant oil.

♦ Observe the following if leak detection fluid has already been

poured into a refrigerant circuit in the course of previous repair

work: Only add new leak detection fluid if refrigerant oil is re‐

newed. If only some of the refrigerant oil has been renewed,

just add the corresponding quantity of leak detection fluid. Af‐

ter replacing 100 ml of refrigerant oil on a vehicle containing

3

250 ml for example, just add 1 ml (cm ) of UV leak detection

additive.

♦ Certain materials and their compounds (e.g. oxidation prod‐

ucts on aluminium components, anti-corrosion waxes) also

show up under UV light.

♦ Certain types of air conditioner service station allow you to in‐

troduce the UV leak detection additive directly (observe the

information in the operating instructions of the air conditioner

service station).

Proceed as follows with a completely empty refrigerant circuit to

avoid allowing more refrigerant than is absolutely necessary for

174

Rep. gr.87 - Air conditioning system

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

leak detection to escape into the environment when localising re‐

frigerant circuit leaks:

– Evacuate the refrigerant circuit using the air conditioner serv‐

ice station ⇒ page 86 .

Note

♦ If evacuation already reveals a major leak, this is to be located

and eliminated as described ⇒ page 183 and ⇒ page 86 .

♦ With the leak detection system - VAS 6201- , it is also possible

to add UV leak detection additive to a charged or open refrig‐

erant circuit ⇒ page 176 .

Continue as follows if evacuation does not reveal any leakage or

if the leakage is so slight that it is not possible to determine the

leakage location on evacuation:

♦ Adding UV leak detection additive to the refrigerant circuit us‐

ing the air conditioner service station ⇒ page 175 .

♦ Adding UV leak detection additive to the refrigerant circuit us‐

ing the leak detection system - VAS 6201- ⇒ page 176 .

Adding UV leak detection additive to the refrigerant circuit using

the air conditioner service station

– Adding UV leak detection additive and the specified quantity

of refrigerant to the refrigerant circuit using the air conditioner

service station ⇒ page 292 .

Note

The quantity of UV leak detection additive to be added to a re‐

3

frigerant circuit with a refrigerant oil quantity of 100 to 150 cm

using the hand-operated pump - VAS 6201- of the leak detection

3

system - VAS 6201- is 2.5 +/- 0.5 cm . If the quantity of refrigerant

oil in the refrigerant circuit is greater, a corresponding quantity of

3

UV leak detection additive must be added (e.g. 5.0 +/- 0.5 cm for

3

a refrigerant circuit with a refrigerant oil quantity of 250 cm ).

When adding the UV leak detection additive with an air condi‐

tioner service station, the amount required may differ and atten‐

tion must therefore be paid to the corresponding operating

instructions. For the corresponding refrigerant oil quantity in the

refrigerant circuit, refer to ⇒ page 333 .

Special tools and workshop equipment required

♦ Air conditioner service station with facility for adding UV leak

detection additive to the refrigerant circuit ⇒ Electronic parts

catalogue (Tools; Workshop equipment/tools; Air condition‐

ing/heating).

♦ Approved leak detection additive ⇒ Electronic parts catalogue

(Tools; Workshop equipment/tools; Air conditioning/heating).

5. Refrigerant circuit

175

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

♦ Cleaning agent - VAS 6201/3- -3-

♦ UV leak detector lamp - VAS 6201/4- -4-

♦ UV-absorbing safety goggles - VAS 6201/6- -5-

♦ Sticker - VAS 6201/7- -6-

– Affix a sticker next to the service connections to indicate that

UV leak detection additive has been added to this refrigerant

circuit.

– Start up the air conditioner.

Note

♦ The air conditioner must be operated for at least 60 min. to

distribute the additive through the entire refrigerant circuit (the

air conditioner compressor must be running). Depending on

the extent of the leak, the leakage location may already be‐

come visible under UV light within this period.

♦ Depending on its size and location, it may now take several

days for sufficient refrigerant oil with UV leak detection additive

to emerge to identify the leakage point clearly.

– Use a UV lamp VAS 6196/4 to locate the refrigerant circuit leak

⇒ page 182 .

Adding UV leak detection additive to the refrigerant circuit using

the leak detection system - VAS 6201-

Special tools and workshop equipment required

♦ Leak detection system - VAS 6201-

176

Rep. gr.87 - Air conditioning system

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

The VAS 6201 leak detection system includes the following tools

⇒ Electronic parts catalogue (Tools; Workshop equipment/tools;

Air conditioning/heating).

1 - Hand pump with low-pressure service hose, service cou‐

pling and non-return valve - VAS 6201/1-

2 - Cartridge - VAS 6201/2- (with UV leak detection additive)

3 - Cleaning solution - VAS 6201/3-

4 - UV leak detection lamp - VAS 6201/4-

5 - UV-absorbing eye protection - VAS 6201/6-

6 - Sticker - VAS 6201/7-

7 - Tube

VAS 6201/8

8 - Protective gloves - VAS 6201/9-

Note

♦ The following procedure describes the addition of UV leak de‐

tection additive using the hand pump - VAS 6201- . Observe

the corresponding operating instructions if the UV leak detec‐

tion additive is to be added to the refrigerant circuit using a

different tool (e.g. an air conditioner service station).

♦ The quantity of UV leak detection additive to be added to a

refrigerant circuit with a refrigerant oil quantity of 100 to 150

3

cm using the hand-operated pump - VAS 6201- is indicated

3

in the following (2.5 +/- 0.5 cm ). If the quantity of refrigerant

oil in the refrigerant circuit is greater, a corresponding quantity

of UV leak detection additive must be added (e.g.

3

5.0 +/- 0.5 cm for a refrigerant circuit with a refrigerant oil

3

quantity of 250 cm ). For the corresponding refrigerant oil

quantity in the refrigerant circuit, refer to ⇒ page 333 .

♦ Observe the quantity of UV leak detection additive given in the

corresponding operating instructions if the UV leak detection

additive is to be added to the refrigerant circuit using a different

tool (e.g. an air conditioner service station).

Adding UV leak detection additive with refrigerant circuit empty

The cartridge -A- contains 15.4 ml of UV leak detection additive

(one unit -B- corresponds to 2.5 ml).

5. Refrigerant circuit

177

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

– Assemble hand pump - VAS 6201- , item -1- with cartridge,

item -2- -VAS 6201/2- .

– Insert filler tube - VAS 6201/8- ( ⇒ page 177 item -7-) in hand

pump.

– Open hand pump service valve.

Note

♦ When the refrigerant circuit is empty, the UV leak detection

additive can be added to the circuit via a service connection

or an open connection.

♦ If the refrigerant circuit is empty, it may be better to add the

UV leak detection additive by way of a joint (e.g. if a joint has

already been unfastened). In this way, no UV leak detection

additive is left in the service connection and the connection

does not have to be cleaned.

♦ Addition of UV leak detection additive to the refrigerant circuit

by way of a service connection ⇒ page 180 .

♦ Addition of UV leak detection additive to the refrigerant circuit

by way of an open connection ⇒ page 179 .

178

Rep. gr.87 - Air conditioning system

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

Addition of UV leak detection additive to the refrigerant circuit by

way of an open connection.

– Open the refrigerant circuit at a readily accessible connection.

– Cover the surrounding area with sheeting or absorbent paper.

– Hold filler tube upwards.

– Screw in the toggle of the hand pump until the UV leak detec‐

tion additive emerges from the tube.

3

–

Add 2.5 +/-0.5 ml (millilitre = cm ) of UV leak detection additive

to the refrigerant circuit (for a refrigerant circuit with a refrig‐

3

erant oil quantity of 100 to 150 cm ).

Note

Observe the following if UV leak detection fluid has already been

poured into a refrigerant circuit in the course of previous repair

work: Only add new UV leak detection fluid if refrigerant oil is re‐

newed. If only some of the refrigerant oil has been renewed, only

add the corresponding quantity of UV leak detection additive. Af‐

ter replacing 100 ml of refrigerant oil on a vehicle containing 250

3

ml for example, just add 2 ml (cm ) of UV leak detection additive.

– Renew O-ring at open connection.

– Assemble refrigerant circuit.

– Affix a sticker next to the service connections to indicate that

leak detection fluid has been added to this refrigerant circuit.

– Evacuate and charge the refrigerant circuit as specified

⇒ page 86 and ⇒ page 91 .

– Start up the air conditioner.

Note

♦ The air conditioner must be operated for at least 60 min. to

distribute the additive through the entire refrigerant circuit (the

air conditioner compressor must be running). Depending on

the extent of the leak, the leakage location may already be‐

come visible under UV light within this period.

♦ Depending on its magnitude and location, it may now take

several days for sufficient refrigerant oil with additive to

emerge to clearly localise the leakage point.

– Use a UV lamp VAS 6196/4 to locate the refrigerant circuit leak

⇒ page 182 .

5. Refrigerant circuit

179

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

Adding UV leak detection additive with refrigerant circuit charged

Note

♦ Observe the following if leak detection fluid has already been

poured into a refrigerant circuit in the course of previous repair

work: Only add new leak detection fluid if refrigerant oil is re‐

newed. If only some of the refrigerant oil has been renewed,

just add the corresponding quantity of leak detection fluid. Af‐

ter replacing 100 ml of refrigerant oil on a vehicle containing

3

250 ml for example, just add 1 ml (cm ) of UV leak detection

additive.

♦ A small quantity of UV leak detection additive remains in the

service connection. This is to be carefully removed so as to

avoid subsequent erroneous 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.

– Detach cap from service connection on low-pressure side of

refrigerant circuit.

– Assemble hand pump - VAS 6201- , item -1- with cartridge,

item -2- -VAS 6201/2- .

– Insert the tube - VAS 6201/8- ( ⇒ page 177 item -7-) in the

service coupling and open the service coupling by screwing in

the handwheel. Hold the hose upwards and screw in the toggle

of the hand pump until the UV leak detection additive starts to

emerge from the tube.

Note

Make sure hand pump hose is completely filled with refrigerant.

– Close service coupling and remove filler tube from locking

mechanism.

180

Rep. gr.87 - Air conditioning system

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

– Cover area around service connection on vehicle with sheet‐

ing or absorbent paper.

– Connect filler unit to refrigerant circuit service connection on

vehicle.

– Open service connection by screwing in handwheel.

– Screw in toggle of hand-operated pump and add 2.5 +/-0.5 ml

3

(millilitre = cm ) of UV leak detection additive to the refrigerant

circuit (for a refrigerant circuit with a refrigerant oil quantity of

3

100 to 150 cm ).

5. Refrigerant circuit

181

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

– Detach filler unit from service connection.

– Use absorbent paper, for example, to remove the residual UV

leak detection additive from the service connection.

– Seal service connection with cap.

– If necessary, use cleaning solution to clean area around serv‐

ice connection.

– Affix sticker next to service connections to indicate that leak

detection fluid has been added to the refrigerant circuit.

– Start up the air conditioner.

Note

♦ The air conditioner must be operated for at least 60 min. to

distribute the additive through the entire refrigerant circuit (the

air conditioner compressor must be running). Depending on

the extent of the leak, the leakage location may already be‐

come visible under UV light within this period.

♦ Depending on its magnitude and location, it may now take

several days for sufficient refrigerant oil with additive to

emerge to clearly localise the leakage point.

– Use a UV lamp VAS 6196/4 to locate the refrigerant circuit leak

⇒ page 182 .

Finding leaks in refrigerant circuit with UV lamp VAS 6196/4

WARNING

Never look into UV lamp.

Never point UV lamp at other people.

182

Rep. gr.87 - Air conditioning system

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

Note

♦ The air conditioner must be operated for at least 60 min. after

adding the UV leak detection additive so that the additive is

distributed through the entire refrigerant circuit (the air condi‐

tioner compressor must be running). Depending on the extent

of the leak, the leakage location may already become visible

under UV light within this period.

♦ Depending on its magnitude and location, it may take several

days for sufficient refrigerant oil with additive to emerge to

clearly localise the leakage point.

♦ In the event of leaks at the evaporator, the additive may be

washed out with the condensation and emerge via the con‐

densation drain. As considerable work is required on most

vehicles to gain access to the evaporator, a check e.g. at the

condensation drain can provide an indication of evaporator

leakage. However, this requires the additive to have been in

the refrigerant circuit for a lengthy period (several days).

♦ The safety goggles are not only designed to provide eye pro‐

tection. They also make the UV leak detection additive more

readily visible under UV light.

♦ Depending on the accessibility of various parts of the refriger‐

ant circuit, it may be necessary to remove certain vehicle

components (e.g. the bumper or air cleaner).

♦ Certain parts of the refrigerant circuit are only supplied with a

small quantity of refrigerant oil in the course of air conditioner

operation (e.g. top-mounted cap of receiver attached to con‐

denser on Audi A8 2010 >). In the event of leakage at such

locations, it may take longer for a sufficient amount of refrig‐

erant with refrigerant oil and additive which shows up under

ultraviolet light to emerge for leak detection. It may therefore

be advisable to use an electronic leak detector to search for

leaks in these areas

⇒ “5.6.1 Tracing leaks in refrigerant circuit using electronic

leak detector (e.g. V.A.G 1796)”, page 172 .

♦ .

– Move vehicle to a poorly lit area of the workshop (daylight or

bright artificial lighting diminishes the effect of the UV light).

– Check the accessibility of the various parts of the refrigerant

circuit and remove any components in the surrounding area

which prevent a clear view of the refrigerant circuit compo‐

nents (e.g. noise insulation and bumper).

– Wear safety goggles to protect the eyes.

– Connect the UV lamp to a 12 V battery (vehicle battery). Take

care to ensure correct polarity of connections.

– Switch on UV lamp and illuminate components of refrigerant

circuit. Locations at which leakage has caused refrigerant, re‐

frigerant oil and therefore also UV leak detection additive to

emerge are lit up under UV light (fluorescent).

5.6.3

Locating leaks using vacuum test with

air conditioner service station or nitro‐

gen pressure test

Vehicles with high-voltage system (hybrid vehicles)

For all work on vehicles with a high-voltage system, note the ad‐

ditional warning instructions for working on such vehicles

5. Refrigerant circuit

183

Audi 100 1991 ➤ , Audi 80 1992 ➤ , Audi A1 2011 ➤ , Audi A1 Sportback 2 ...

Air conditioner with refrigerant R134a - Edition 11.2018

⇒ “1 Warning instructions when working on vehicles with high-

voltage system”, page 1 and ⇒ Electrical system; Rep. gr. 93 ;

General warning instructions for work on the high-voltage sys‐

tem .

– On vehicles with high-voltage system, switch off (deactivate)

auxiliary air conditioner function ⇒ Owner's Manual and ⇒

Infotainment/MMI Operating Manual .

All vehicles

– Switch off ignition.

♦ Establishing leaks by way of vacuum test with air conditioner

service station or nitrogen pressure test

⇒ “5.3.4 Evacuating refrigerant circuit with air conditioner serv‐

ice station”, page 86

Note

♦ Minor refrigerant circuit leaks (loss amounting to less than 100

g of refrigerant per year) can generally not be established by

way of the vacuum test or nitrogen pressure test. The quantity

of air ingressing or nitrogen escaping is not sufficient to be

audible.

♦ Depending on the ambient conditions (ambient noise, leakage

location etc.), it may also not always be possible to establish

refrigerant circuit leaks involving a loss of more than 100 g of

refrigerant per year using the vacuum or nitrogen pressure

test. The quantity of air entering or the quantity of nitrogen

escaping may not be sufficient to produce any noise which

would make it possible to identify the location of the leak.

♦ Depending on the ambient conditions, it may be possible to

detect major refrigerant circuit leaks (e.g. caused by flying

stones at the condenser, loss of refrigerant more than 100 g

per day) from the noise occurring at the fault location during

the vacuum or nitrogen pressure test for example

⇒ “5.3.4 Evacuating refrigerant circuit with air conditioner serv‐

ice station”, page 86 .

184

Rep. gr.87 - Air conditioning system

Download User Manual App

Refrigerant circuit -> Tracing leaks in refrigerant circuit for Your Audi A2 SUV 1999-2005

Related Topics

Refrigerant circuit

Popular Owner Manuals

Latest Owner Manuals