Get Air conditioning system -> 1.4.3 Searching for leaks with UV leak detection system Guide for Volkswagen Touran 4 Door Second Generation (2015-2022)

Arteon 2018 ➤ , Atlas 2017 ➤ , CC 2012 ➤ , Caddy 2016 ➤ , Crafter 201 ...

Air conditioning systems with refrigerant R1234yf - General information - Edition 07.2017

1.4.3

Searching for leaks with UV leak detec‐

tion system

Note

♦ Certain leaks are difficult or impossible to find using an elec‐

tronic leak detection device. To investigate these leaks, leak

detection can be performed using the leak detection system

⇒ Electronic parts catalogue .

♦ Refrigerant and refrigerant oil leaks out of the refrigerant circuit

when the circuit has a leak. This oil generally remains in the

vicinity of the leak location. To make the oil visible under^lU^kV

light, a small amount of fluorescent fluid must be added to the

refrigerant circuit. This fluid (PAG oil with an additive which

lights up under UV light) is injected into the refrigerant circuit

and distributed with the refrigerant oil when the air conditioning

system is switched on.

♦ The air conditioning system must be operated for at least

60 minutes to ensure that the injected leak detecting additive

is distributed throughout the entire refrigerant circuit (air con‐

ditioner compressor must run). The leak may become visible

under UV light after a short period, but this depends on the

size of the leak.

♦ The refrigerant oil with additive, which lights up under UV light,

can be added directly in an open circuit or charged after emp‐

tying the circuit with air conditioner service station via the

service connection.

♦ If the leak detection additive is added to the refrigerant circuit

via the service connection, a small amount of leak detection

additive will be deposited in the service connection. Carefully

remove any deposits so that this area is not mistaken for a leak

during subsequent leak detection.

♦ If a component from a circuit in which leak detection additive

is filled is renewed, thoroughly clean the connection points to

other components after assembling the refrigerant circuit. Dur‐

ing subsequent leak detection, deposits of leak detection ad‐

ditive could otherwise be mistaken for leaks at the connecting

point.

♦ When purging the refrigerant circuit, refrigerant oil and there‐

fore also leak detection additive also enter the air conditioner

service station . The refrigerant oil is separated from the re‐

frigerant in the oil separator of the air conditioner service

station and removed from the air conditioner service station

via the drainage outlet. The drained refrigerant oil may not be

reused. It must be replaced with fresh refrigerant oil.

♦ If leak detection fluid was injected during a previous repair of

the refrigerant circuit, observe the following: do not inject new

leak detection fluid unless the refrigerant machine oil has been

replaced. If only some of the refrigerant machine oil was re‐

placed then only the respective amount of leak detection fluid

should be injected. If, for example, 100 ml of refrigerant oil is

replaced in a vehicle with 250 ml of refrigerant oil, inject only

1 ml (cm³) of leak detection additive.

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

ucts on components made from aluminium, corrosion protec‐

tion wax, etc.) also light up under UV light.

1. Refrigerant circuit

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Arteon 2018 ➤ , Atlas 2017 ➤ , CC 2012 ➤ , Caddy 2016 ➤ , Crafter 201 ...

Air conditioning systems with refrigerant R1234yf - General information - Edition 07.2017

♦ Depending on the type of air conditioner service station , it can

also be used to add the leak detection additive directly into the

system. See the operating instructions of your air conditioner

service station ⇒ Operating instructions air conditioner service

station .

Leak detection on an empty, leaking refrigerant circuit

– With a completely empty refrigerant circuit, proceed as follows

to ensure that no more refrigerant than necessary enters the

environment during testing:

– Evacuate refrigerant circuit with air conditioner service station

⇒ “2.5 Evacuating refrigerant circuit”, page 140 .

Note

If a larger leak is detected during the evacuation process, deter‐

mine the cause and rectify as described

⇒ “1.4.4 Detecting leaks in a vacuum test using air conditioner

service station , or in a pressure test”, page 77 and

⇒ “2.5 Evacuating refrigerant circuit”, page 140 .

If during the evacuation process no leak is detected or a very

small leak is detected that cannot be located during evacuation,

proceed as follows.

Note

♦ Only use UV leak detection additive approved for R1234yf re‐

frigerant.

♦ The leak detection additive contains refrigerant oil for the most

part. Since special refrigerant oils are required for R1234yf

refrigerant, only UV leak detection additives may be used that

use this oil as a carrier. UV leak detection additives developed

for R134a refrigerant are therefore unsuitable.

♦ For refrigerant circuits with R1234yf and R134a refrigerant,

different refrigerant oils (PAG oils) are used, which is why it is

important to ensure correct allocation of the leak detection ad‐

ditive (PAG oil with an additive that lights up under UV light).

♦ Charge the refrigerant circuit with UV leak detection additive

using the air conditioner service station ⇒ page 75 .

♦ Charge the refrigerant circuit with UV leak detection additive

using the leak detection system ⇒ page 75 .

– Charge the refrigerant circuit with the specified amount of UV

leak detection additive and the requisite amount of refrigerant

⇒ page 72 , ⇒ “2.6 Charging refrigerant circuit”, page 146

and ⇒ Heating, air conditioning; Rep. gr. 00 ; Technical data .

– Run the air conditioning system for at least 60 minutes with

the air conditioner compressor switched on.

– Investigate leaks with UV leak detection system

⇒ page 75 .

Charge the refrigerant circuit with UV leak detection additive using

the air conditioner service station .

– Charge the refrigerant circuit with UV leak detection additive

and the requisite amount of refrigerant using air conditioner

service station ⇒ “2.6 Charging refrigerant circuit”, page 146

and ⇒ Heating, air conditioning; Rep. gr. 00 ; Technical data .

Rep. gr.87 - Air conditioning system

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Arteon 2018 ➤ , Atlas 2017 ➤ , CC 2012 ➤ , Caddy 2016 ➤ , Crafter 201 ...

Air conditioning systems with refrigerant R1234yf - General information - Edition 07.2017

Note

♦ The amount of UV leak detection additive to be charged in the

refrigerant circuit with a refrigerant oil volume up to 150 cm³

is 3.0 ± 0.5 ml. If the volume of refrigerant oil in the refrigerant

circuit is greater, more UV leak detection additive must be

added accordingly, e.g. 5.0 ± 0.5 ml in a refrigerant circuit with

a refrigerant oil volume of 250 cm³. If the UV leak detection

additive is filled with an air conditioner service station , the

volume to be set in your air conditioner service station may

differ. Therefore, observe the relevant operating instructions

⇒ Operating instructions Air conditioner service station .

♦ For the specific volume of refrigerant oil in the refrigerant cir‐

cuit, refer to the vehicle-specific workshop manual ⇒ Heating,

air conditioning; Rep. gr. 00 ; Technical data .

♦ If leak UV leak detection additive was injected during a previ‐

ous repair of the refrigerant circuit, observe the following: do

not inject new UV leak detection additive unless the refrigerant

machine oil has been replaced. If only some of the refrigerant

machine oil was replaced then only the respective amount of

UV leak detection additive should be injected. If, for example,

50 ml of refrigerant oil is replaced in a vehicle with 150 ml of

refrigerant oil, inject only 1.0 ml (cm³) of UV leak detection

additive.

The leak detection system comprises the following parts:

♦ Cleaning agent -3-

♦ UV leak detection lamp -4-

♦ UV absorbing eye protection -5-

♦ Sticker -6-

♦ Gloves -8-

Note

Items -1-, -2- and -7- in the diagram can be disregarded.

Special tools and workshop equipment required

♦ Leak detecting system

♦ Air conditioner service station with means of adding UV leak

detection additive in the refrigerant circuit ⇒ Electronic parts

catalogue .

♦ Approved leak detection additive ⇒ Electronic parts cata‐

logue .

– Evacuate the refrigerant circuit as per the instructions, and

charge the system with UV leak detection additive and refrig‐

erant ⇒ “2.5 Evacuating refrigerant circuit”, page 140 and

⇒ “2.6 Charging refrigerant circuit”, page 146 .

– Wait until the pressures on the high pressure and low pressure

side have settled.

1. Refrigerant circuit

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Air conditioning system -> 1.4.3 Searching for leaks with UV leak detection system for Your Volkswagen Touran 4 Door Second Generation (2015-2022)

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