volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

Clearing refrigerant circuit of contaminants > < Searching for leaks in refrigerant circuits using leak detectorV.A.G 1796
Detecting leaks in refrigerant circuit using leak detecting systemVAS 6196 or leak detecting systemVAS 6201
Detecting leaks in refrigerant circuit using leak detecting system -VAS 6196- or leak detecting system -VAS 6201-
  Note
Small leaks can be detected with, for example, an UV leak detector additive.
–  Evacuate refrigerant circuit using an air conditioner service station → Chapter.
  Note
t  If a larger leak is detected during the evacuation process, determine cause and rectify as described → Chapter.
t  If during the evacuation process no leak is detected or a very small leak is detected that but cannot be located, proceed as follows → Chapter.
t  Refrigerant gas is quickly dispersed by air motion. Therefore drafts must be avoided during a search for leaks.
t  If the refrigerant circuit is completely empty, charge with about 10 % of refrigerant capacity (sticker R134a or vehicle-specific workshop manual).
   
Leak detecting system -VAS 6196-
or
  W00-10195
Leak detecting system -VAS 6201-
1 - Hand pump with low-pressure service hose, service coupling and non-return valve -VAS 6201/1-
2 - Cartridge -VAS 6201/2-
3 - Cleaning solution -VAS 6201/3-
4 - UV leakage detector lamp -VAS 6201/4-
5 - UV absorbing eye protection -VAS 6201/6-
6 - Label -VAS 6201/7-
7 - TubeVAS 6201/8
8 - Protective gloves -VAS 6201/9-
  A87-0494
Injecting leak detecting additive into an empty refrigerant circuit.
The cartridge -A- contains 15.4 ml of leak detecting additive (one unit -B- equates to 2.5 ml).
  A87-0490
–  Assemble hand pump -VAS 6201- item -1- and cartridge item -2--VAS 6201/2-.
–  Connect filler hose -VAS 6201/8- ( → Anchor item -7-) to hand pump.
–  Open service valve of hand pump.
  A87-0496
The leak detecting additive can be injected into the empty refrigerant circuit via an open circuit connection.
–  Open an easily assessable connection in the refrigerant circuit.
–  Cover area of connection with foil or absorbent paper.
–  Hold tube upwards
–  Turn T-bar of hand pump until the leak detecting additive flows out of the tube.
–  Inject 2.5 ± 0.5 ml (millilitre = cm3) of leak detecting additive into the refrigerant circuit.
  Note
Note the following, if a leak detecting additive has been injected during a previous repair of the refrigerant circuit, only inject new leak detecting additive if the refrigerant machine oil has been replaced. If only some of the refrigerant machine oil was replaced then only the respective amount of leak detecting additive should be injected. If for example 100 ml of machine oil was replaced on a vehicle with 250 ml of refrigerant machine oil, inject only 1 ml (cm3) of leak detecting additive.
–  Renew O-rings at opened connection.
–  Reassemble refrigerant circuit again.
–  Attach a label, close to the service connection, which has information showing that the refrigerant circuit has been injected with a leak detecting additive.
–  Evacuate and fill the refrigerant circuit as per specifications → Chapter and → Chapter.
–  Start air conditioning system.
  Note
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 conditioner compressor must run). The leak may become visible after a short period, but this depends on the size of the leak.
–  Use UV lamp VAS 6196/4 to search for the leak in the refrigerant circuit → Anchor.
Injecting leak detecting additive to a charged refrigerant circuit.
  Note
t  Note the following, if a leak detecting additive has been injected during a previous repair of the refrigerant circuit, only inject new leak detecting additive if the refrigerant machine oil has been replaced. If only some of the refrigerant machine oil was replaced then only the respective amount of leak detecting additive should be injected. If for example 100 ml of machine oil was replaced on a vehicle with 250 ml of refrigerant machine oil, inject only 1 ml (cm3) of leak detecting additive.
t  A small amount of leak detecting additive remains in the service connection. Carefully remove the remains as this will help to prevent these remains being falsely identified as a leak when leak detection is carried out in the future.
  A87-0491
The cartridge -A- contains 15.4 ml of leak detecting additive (one unit -B- equates to 2.5 ml).
  A87-0490
–  Switch off ignition.
–  Remove sealing cap from service connection on the low-pressure side of the refrigerant circuit.
–  Assemble hand pump -VAS 6201- item -1- and cartridge item -2--VAS 6201/2-.
  Note
Ensure the hose of the hand pump is completely filled with leak detecting additive.
–  Fit the quick release coupling to the service connection of the low-pressure side and open the service coupling by turning the hand wheel. Hold hose upwards and turn T-bar of hand pump until the leak detecting additive starts to flow out of the tube.
  A87-0496
–  Cover area of service connection on vehicle with foil or absorbent paper.
–  Turn T-bar of hand pump and inject 2.5 ± 0.5 ml (millilitre = cm3) of leak detecting additive into the refrigerant circuit.
  A87-0493
–  Close the service coupling and remove it from the service connection.
–  Remove the remains of the leak detecting additive from the service connection, with for example, absorbent paper.
–  Seal service connection using the sealing cap.
–  If necessary, clean the area of the service connection using the cleaning solution.
–  Attach a label, close to the service connection, which has information showing that the refrigerant circuit has been injected with a leak detecting additive.
–  Start air conditioning system.
  Note
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 conditioner compressor must run). The leak may become visible after a short period, but this depends on the size of the leak.
–  Use UV lamp VAS 6196/4 to search for the leak in the refrigerant circuit → Anchor.
Searching for leaks in the refrigerant circuit using UV lamp VAS 6196/4.
  WARNING
Do not look into the UV lamp.
Do not point the UV lamp at another person.
  Note
t  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 conditioner compressor must run). The leak may become visible after a short period, but this depends on the size of the leak.
t  For leaks on the evaporator, the additive can wash off with the condensed water and leak out from the condensed water drain-off. As the evaporator is not accessible on the majority of models without a great amount of pre-preparation, a check of the condensed water drain point can indicate a leaking evaporator. The additive must have been in the refrigerant circuit for a long time to make this possible.
t  The eye protect is not only required to protect the eyes, it also amplifies the illumination of the additive under the UV lamp.
t  Independent of the accessibility to the various components of the refrigerant circuit, it may become necessary to remove certain components from the vehicle (e.g. bumper or air filter).
  A87-0495
–  Position the vehicle in a darker area of the workshop (in daylight or under strong lighting the effect of the UV lamp is greatly reduced).
–  Check the accessibility to the various components of the refrigerant circuit and remove components in the vicinity of the refrigerant circuit that obstruct the view of the respective circuit components (e.g. sound insulation and bumper).
–  Protect eyes with protective glasses.
–  Connect UV lamp to a 12 V battery (vehicle battery). Ensure that it is connected to the correct terminals.
–  Switch on UV lamp and illuminate components of the refrigerant circuit. Locations where leaking refrigerant along with refrigerant oil and leak detecting additive can leak out, light-up (fluorinate) under UV light.
  Note
The leak detection additive can be allowed to remain in the refrigerant circuit.
  A87-0492

Clearing refrigerant circuit of contaminants > < Searching for leaks in refrigerant circuits using leak detectorV.A.G 1796