Adding UV-leak detection additive when the refrigerant circuit is full

WARNING: This page is about a different car, the 2023 Audi SQ8, 2023 Audi RS Q8, and 2023 Audi Q8. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

If leak detection fluid was filled already in a refrigerant circuit for an earlier repair, note the following: only add new leak detection additive 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 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).

Fig 1: Identifying Cartridge & One Unit

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-- Switch off the ignition.

Fig 2: Assembling Hand Pump VAS 6201 With Cartridge - VAS 6201/2

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-- Remove the closure cap from service connection of low pressure side in refrigerant circuit.

-- Assemble the Leak Detection Kit -VAS 6201A- item -1- with the Leak Detection Kit - Cartridge -VAS 6201/2- item -2-.

-- Insert Leak Detection Kit - Filler Tube -VAS 6201/8- (Refer to Add UV-leak detection additive using the in the refrigerant circuit. VAS 6201/8 item -7-.) into the service coupling and open the service coupling by screwing in the 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 the 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.

Fig 3: Adding Leak Detection Additive To Refrigerant Circuit

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-- 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.

Fig 4: Identifying Leak Detection Additive Label

Courtesy of AUDI OF AMERICA, LLC

-- Remove the rest of the UV-leak detection additive from the service connection, for example using absorbent paper.

-- Seal the service connection with the closure 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 definitely determine the leaking area.

-- Find the leak in the refrigerant circuit with the UV lamp VAS 6196/4. Refer to Detecting leaks on the refrigerant circuit using UV lamp VAS 6196/4 .