SEAT Workshop Service and Repair Manuals

Searching for leaks on the refrigerant circuit using the leak detection system VAS 6201A   Note t  Certain leaks are difficult or even impossible to find using an electronic leak detector. Such leaks can be detected using the VAS 6201A leak detector. t  Refrigerant circuit leaks result in a loss of refrigerant oil together with the refrigerant. The oil usually remains in the vicinity of the leak. Adding a small quantity of fluorescent 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 becomes distributed with the refrigerant oil when the air conditioner is switched on. t  It is necessary to operate the air-conditioning system for at least 60 minutes (AC compressor running) to ensure that the additive is distributed uniformly in the entire AC circuit. t  The refrigerant oil containing the additive, which shows up under UV light, can either be filled 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 6201A) via the service connection on the vacuum side. t  If the leak detection additive is applied via the service connection on the low-pressure end with the refrigerant circuit charged, a small quantity of 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. t  If a component forming part of a circuit into which the leak detection additive is poured has to be renewed, thoroughly clean joints with other components after assembling refrigerant circuit. These leak detector additive residues at the connection points could be evaluated erroneously as leakage when searching for leaks later. t  On discharging the refrigerant circuit, refrigerant oil and thus also leak detection additive ingresses into the air conditioner 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 is to be replaced with fresh refrigerant oil. t  Observe the following if leak detection fluid has already been poured into a refrigerant circuit in the course of previous repair work: Only pour in fresh leak detection fluid if refrigerant oil is replaced. If only some of the refrigerant oil has been renewed, just add the corresponding quantity of leak detection fluid. If, for example, 100 ml of refrigerant oil has been replaced on a vehicle containing 250 ml, only add 1 ml (cm3) of leak detection additive. t  Certain materials and their compounds (e.g. oxidation products on aluminium components, anti-corrosion waxes) also show up under UV light.

Tools and other items required: VAS 6,201A 1 -  Hand pump with low-pressure service hose, service coupling and non-return valve -VAS 6201/1- 2 -  Cartridge -VAS 6201/2- 3 -  Cleaning solvent -VAS 6201/3- 4 -  UV leakage detector lamp -VAS 6201/4- 5 -  UV protective goggles -VAS 6201/6- 6 -  Labels -VAS 6201/7- 7 -  Filler tubeVAS 6201/8 8 -  Protective gloves -VAS 6201/9-

Pouring in leak detection additive with refrigerant circuit empty The cartridge -A- contains 15.4 ml of leak detecting additive (one unit -B- equates to 2.5 ml).

–  Mount the hand pump -VAS 6201- Pos. -1- with the cartridge Pos. -2--VAS 6201/2-. –  Mount the filling tube -VAS 6201/8- ( → Anchor Pos. -7-) to the hand pump. –  Open the service valve of the hand pump.

The leak detection additive can be filled into the empty refrigerant circuit through an open connection. –  Separate a connection position on the refrigeration circuit that is easy to access. –  Cover the area around the connecting position with film or absorbent paper. –  Hold the pipes upwards. –  Screw in the screw knob of the hand pump in until leak detection additive exits from pipe. –  2.5 ± 0.5 ml (millilitre = cm3) Fill leak detection additive in the refrigerant circuit.   Note If a repair leak detection fluid has already been filled in a refrigerant circuit during a previous leak detection, proceed as follows: Only fill the new leak detection additive when the refrigerant oil is replaced. If only some of the refrigerant oil has been renewed, just add the corresponding quantity of leak detection additives. If, for example, in a vehicle with 250 ml refrigerant oil, 100 ml is replaced, only 1 ml (cm3) of leak detection additive can be filled. –  Replace the O-ring for the separated connecting position. –  Reassemble the refrigerant circuit. –  Apply a sticker near to the service connection that provides information that leak detection additive has been filled into this refrigerant circuit. –  Extract and charge the refrigerant circuit as described. –  Switch the air conditioner on:   Note t  To enable the leak detection additive to be distributed throughout the entire refrigerant circuit, the air conditioner must remain switched on for at least 60 minutes (the air conditioner compressor must run). Depending on the size of the leak, the leak can already be detected during this period. t  Depending on the size and location of the leak, it may take several days before the refrigerant oil with leak detection additive escapes. –  Find leaks on the refrigerant circuit using the UV leak detection lamp VAS 6196/4. Pouring in leak detection additive with refrigerant circuit charged   Note t  If a repair leak detection fluid has already been filled in a refrigerant circuit during a previous leak detection, proceed as follows: Only fill the new leak detection additive when the refrigerant oil is replaced. If only some of the refrigerant oil has been renewed, just add the corresponding quantity of leak detection additives. If, for example, in a vehicle with 250 ml refrigerant oil, 100 ml is replaced, only 1 ml (cm3) of leak detection additive can be filled. t  A small quantity of the leak detection additive remains in the service connection. Carefully remove these residues so that these residues are not mistakenly perceived as a leak with future leak detections.

The cartridge -A- contains 15.4 ml of leak detecting additive (one unit -B- equates to 2.5 ml).

–  Switch ignition OFF. –  Remove the sealing cap of the service connection of the vacuum side of the refrigerant circuit. –  Mount the hand pump -VAS 6201- Pos. -1- with the cartridge -2--VAS 6201/2-.   Note Ensure that hose on hand pump is completely filled with leak detection additive. –  Place the quick connector on the service connection on the low-pressure and open the service connector by turning on the handwheel. Hold hose pointing upward and screw knob on hand pump in until leak detection additive exits from the hose.

–  Cover the area around the service connection with film or absorbent paper. –  By screwing in the screw knob on hand pump 2.5 ± 0.5 ml (Millilitre = cm3) Fill leak detection additive in the refrigeration circuit.

–  Slacken the quick connector and remove from the service connection. –  Remove the residues of the leak detection additive from the service connection with, e.g. absorbent paper. –  Connect the service connection with the sealing cap. –  If required, clean the surroundings of the service connection using a suitable cleaning solvent. –  Apply a sticker near to the service connection that provides information that leak detection additive has been filled into this refrigerant circuit.   Note t  To enable the leak detection additive to be distributed throughout the entire refrigerant circuit, the air conditioner must remain switched on for at least 60 minutes (the air conditioner compressor must run). Depending on the size of the leak, the leak can already be detected during this period. t  Depending on the size and location of the leak, it may take several days before the refrigerant oil with leak detection additive escapes. –  Find leaks on the refrigerant circuit using the UV leak detection lamp VAS 6196/4. Find leaks on the refrigerant circuit using the UV leak detection lamp VAS 6196/4.   WARNING Do not look into the UV lamp. Do not point the UV lamp at another person.   Note t  It is necessary to operate the air-conditioning system for at least 60 minutes (AC compressor running) to ensure that the additive is distributed uniformly in the entire AC circuit. t  Depending on the magnitude and location, it may take several days for sufficient refrigerant oil and additive to emerge to clearly identify 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 on most vehicles the evaporator is not accessible without considerable effort, checking the condensate drain for example can provide an indication of evaporator leakage. This does however require the additive to have been in the refrigerant circuit for a lengthy period (several days). t  The safety goggles are not only designed to provide eye protection. They also make the additive more readily visible under UV light. t  Depending on the accessibility of various parts of the refrigerant circuit, it may be necessary to remove certain vehicle components (e.g. bumper or air cleaner).

–  Move the vehicle to a dark area in the workshop (the effect of the UV lamp is reduced at daylight or with intensive lighting). –  Check accessibility of various parts of the refrigerant circuit and remove components in area of refrigerant circuit which would block view of refrigerant circuit components (e.g. noise insulation and bumper). –  Use eye protection. –  Connect UV lamp to a 12V battery (vehicle battery). Ensure that it is connected to the correct terminals. –  Switch on UV lamp and illuminate components of refrigerant circuit. Locations at which leakage has resulted in the emergence of refrigerant, refrigerant oil and thus also leak detection additive show up under UV light (fluorescent).