Professional Distributor - 30

DIAGNOSTIC TECH
II Ultrasonic Cleaning unit from CPS
Products to help eliminate mold and
mildew smells within the vehicle's
cabin. This device does its job by
introducing nano-droplets of cleaning solution throughout the HVAC air
flow paths.

once where the variable displacement
compressor wasn't working properly
and was barely able to produce pressure. The oil was dark brown. Upon
disassembly of the compressor, the
swash plate pivoting mechanism was
mechanically seized due to lack of
lubrication. See figure 4.

DIAGNOSTICS
Scan tool and sight glass

Fig 2 - Pyle Thermo-Anemometer.

to environmental conditions like forest
fires, suggesting maintenance is good
practice. Additionally, filters may be
checked for restriction using an anemometer as shown in figure 2.

It's always a good practice to perform
a full vehicle scan when addressing
system complaints. There may be
other issues present that could prevent
proper A/C system operation. Some
vehicles may have an engine-related
fault that could inhibit A/C compressor operation.

PRESSURE AND TEMPERATURE
Pressure measurement is a great start
to assessing system operation. Combining that data with temperatures is
a gateway to gaining a deeper perspective into the system's thermodynamic
performance. The ManTooth Wireless
Pressure/Temperature Measurement
Kit from Yellow Jacket, along with
your tablet or smartphone can help
you quickly assess the A/C system's
performance. See figure 5.

Hoses and connections

You'll want to inspect hoses and connections for the presence of oil as a
sign of leakage. Keep in mind that
loose or broken engine mounts can
lead to premature system leaks.

Condensers and evaporator

A/C condensers are frequently subject to small rocks and other debris. In
some cases, there may be aftermarket
screens that can be added to help prevent damage. When looking for leaks
in the condenser area, it may be difficult to locate them until the system
is fully charged and operating under
normal pressures and temperatures.
The evaporator can't always be
inspected easily, but the evaporator
drain can help in terms of diagnostics. If it becomes restricted or plugged,
mold, mildew, and corrosion of the
evaporator can occur. You should also
inspect the drain with a leak detector. In some cases, a borescope may
be used to have a look if warranted. A
system operating in warm temperatures
and high humidity should produce a
noticeable amount of condensate from
the drain. In my shop, we use the MiST

Fig 4 - Compressor wear and failure inspection
after cleaning.

Fig 3 - Visual sight glass

Years ago, most vehicles possessed
sight glass to help the technician check
a system's charge. Although you may
come across a some cars still using one,
they can be used to check charge levels
and whether the system contains fluorescent dye. However, there's another
type of sight glass that can help take a
deeper look. Airsept offers sight glass
that can provide technicians with additional information. See figure 3. This
tool can help assess the internals of the
A/C system.
When analyzing system performance, the refrigeration oil condition
can be very telling. We had a vehicle

30 Professional Distributor I February 2021 I VehicleServicePros.com

Fig 5 - Electronically Controlled Compressor
Tester alongside the ManTooth

VARIABLE DISPLACEMENT
COMPRESSORS - VDC
The ECCS06 by 4Seasons is a tool
that we've been using in our shop to
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