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Air conditioning systems with refrigerant R1234yf - General information - Edition 07.2017
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 con‐
ditioner compressor must run). The leak may become visible
under UV light after a short period, but this depends on the
size of the leak.
♦ Depending on the size and location of the leak, it can take
several days until sufficient refrigerant oil with UV leak detec‐
tion additive has leaked out and the leak can be easily identi‐
fied as such.
♦ In the event of leaks at the evaporator, the additive may be
washed out with the condensate and emerge via the conden‐
sate drain. As the evaporator is not accessible on the majority
of models without a great amount of work, a check of the con‐
densed water drain point can indicate a leaking evaporator.
This does however require the additive to have been in the
refrigerant circuit for a lengthy period (several days).
♦ The protective eye wear is not only required to protect the
eyes. It also amplifies the illumination of the UV leak detection
additive under the UV lamp.
♦ Depending on how easy it is to reach various components in
the refrigerant circuit, it may be necessary to remove certain
parts from the vehicle (e.g. bumper or air filter).
♦ Only a small amount of refrigerant oil reaches certain areas of
the refrigerant circuit during operation of the air conditioning
system (e.g. a cap fitted at the top of a receiver installed on
the condenser). If there is a leak in these areas, it may take
quite some time before a sufficient quantity of refrigerant with
refrigerant oil and additive escapes at this point and can be lit
up under UV light showing where the leak is. At these points,
therefore, it may be more pertinent to search for a leak using
an electronic leak detection device
⇒ “1.4.2 Searching for leaks in refrigerant circuits using an
electronic leak detector”, page 69 .
– Position the vehicle in a darker area of the workshop (in day‐
light or under strong lighting the effect of the UV lamp is greatly
reduced).
– Check accessibility to various components of the refrigerant
circuit and remove parts in the vicinity of the refrigerant circuit
that obstruct the view of the refrigerant circuit components
(e.g. noise insulation and bumper).
– Protect eyes with safety goggles.
– Connect UV lamp to a 12 V battery (vehicle battery). Ensure
that the polarity of the connections is correct.
– Switch on the UV lamp and light up the components in the
refrigerant circuit. Positions at which refrigerant - along with
refrigerant oil and leak detection additive - can leak out fluo‐
resce (light-up) under UV light.
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Rep. gr.87 - Air conditioning system
GETth
English 
