Detecting Leaks on the Refrigerant Circuit using
Do not look into UV lamp.
Do not direct UV lamp at other people.
After adding the UV-leak detection additive, the 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 determine definitely the leaking area.
With leaks on the evaporator, leak detection additive is possibly washed off with condensation and flows out via evaporator drain. Since the evaporator is not easily accessible on most vehicles, checking the evaporator drain may indicate if the evaporator is leaking. However, it is necessary for this purpose that leak detection additive has already been in the refrigerant circuit for a long period of time (for example, a few days).
The protective goggles do not only serve as eye protection but also amplify the illumination of leak detection additive under UV light.
Depending on the accessibility of different components in the refrigerant circuit, it may be necessary to remove some vehicle components such as the bumper or air filter.
Only a little refrigerant oil will get onto certain places on the refrigerant circuit when A/C is being used (for example, on the top cover of the receiver/dryer attached to the condenser on an Audi A8 from MY 2010). If there is a leak at this spot, it may take longer until enough refrigerant with refrigerant oil and additive start to leak out, which then can be viewed under UV light. It may be useful to use an electronic leak detector at these locations to find a leak. Refer to REFRIGERANT CIRCUIT, TRACING LEAKS USING ELECTRONIC LEAK DETECTOR (FOR EXAMPLE, .
-- Move vehicle into a slightly darker area of the workshop (with daylight or bright lighting the effect of the UV light is diminished).
-- Check the accessibility of the various components in the refrigerant circuit and remove any components in the area that block access to the refrigerant circuit such as noise insulation and the bumper.
-- Wear protective eyewear to protect the eyes.
-- Connect the UV-lamp to a 12 volt battery (vehicle battery). Observe the correct polarity of connections.
-- Switch on the UV lamp and illuminate the components of refrigerant circuit. Locations where refrigerant, refrigerant oil and UV-leak detection additive has leaked out light up under fluorescent UV light.