Leak Detection On Refrigerant Circuit Using Leak Detection Kit :Vas6201A: Notes
Vehicles with a High Voltage System (Hybrid Vehicles)
Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system. Refer to WARNINGS WHEN WORKING ON VEHICLES WITH HIGH VOLTAGE SYSTEM and the appropriate service information. .
All Vehicles
Certain leaks cannot or only with difficulty be found using an electric leak detection unit. Leak detection can be performed using Leak Detection Kit :VAS6201A .
Refrigerant and refrigerant oil escape when there is a leak in the refrigerant circuit. Generally, this oil remains in the vicinity of the leaking area. A small amount of fluorescent fluid must be added into refrigerant circuit so that this oil becomes visible under UV light. This fluid (PAG oil with an additive that lights up under UV light) is added into the refrigerant circuit and distributes itself with the refrigerant oil when the A/C system is switched on.
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.
Refrigerant oil with additive that lights up under UV-light can be added directly with an open circuit or be pumped into a filled circuit via service connection on the low pressure side using Leak Detection Kit - Hand Pump w/Cartridge :VAS6201/1 (from Leak Detection Kit :VAS6201A ).
If the UV-leak detection additive is added to a filled refrigerant circuit via the service connection on the low pressure side, a small amount of it remains in the service connection. Carefully remove this residual amount so that a leaking area is not detected erroneously upon a later leak detection.
If a component in which UV-leak detection additive has been added is being replaced on a circuit, thoroughly clean the connection areas to the other components after assembling the refrigerant circuit. The UV-leak detection additive residue may register erroneously as leaking areas during later leak detection.
Refrigerant oil as well as UV-leak detection additive get into the service station when evacuating a refrigerant circuit. The refrigerant oil is separated from refrigerant in oil collector of service station and removed from the service station via the draining device. The refrigerant oil drained off must not be poured back in. It must be replaced with new refrigerant oil.
If leak detection fluid was filled already in a refrigerant circuit for an earlier repair, note the following: Only add new leak detection fluid 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.
Certain materials and their connections (for example, oxidation products on aluminum components, corrosion protection growth, etc.) also light up under UV-light.
Depending on the version of the A/C service station, UV-leak detection additive can also be added directly at the top. Refer to the operating instructions that come with the A/C service station.
To prevent more refrigerant than is necessary for the leak test from venting into the air, proceed as follows with the refrigerant circuit completely empty:
-- Evacuate the refrigerant circuit with the A/C service station. Refer to REFRIGERANT CIRCUIT, EVACUATING WITH A/C SERVICE STATION .
If a larger leak is found during evacuation, find and repair it as described. Refer to FINDING LEAKS VIA VACUUM TEST USING A/C SERVICE STATION OR NITROGEN PRESSURE TESTING and REFRIGERANT CIRCUIT, EVACUATING WITH A/C SERVICE STATION .
The UV-leak detection additive can also be filled in a filled or open refrigerant circuit with the Leak Detection Kit :VAS6201A . Refer to Add UV-Leak Detection Additive using the in the Refrigerant Circuit .
If no leak is found during evacuation or there is a leak that is so small that the location cannot be found, proceed as follows.
- Add the UV-leak detection additive using the A/C service station to the refrigerant circuit. Refer to Add the UV-Leak Detection Additive Using the A/C Service Station to the Refrigerant Circuit. .
- Add UV-leak detection additive using the Leak Detection Kit :VAS6201 in the refrigerant circuit. Refer to Add UV-Leak Detection Additive using the in the Refrigerant Circuit .