MACS Monthly Newsletter - 2022 - JUN5

How much to replace?
It 's an age-old question in A/C service when
a compressor has failed: which additional parts
should be replaced beyond the new compressor?
When years ago the system suffered the notorious
" black death " failure, it came down to " how much
can the motorist afford in a balance with the minimum
needed to get the system working decently?
The old rule was " change everything, " which was
hardly a cost-realistic approach. Honda was one of
a number of models that occasionally suffered the
ailment and so it developed an inspection procedure
to evaluate the extent of the failure. The first step
is to check for a buildup of black debris in the desiccant
bag (Figures 5, 6), which is an " automatic "
replacement along with the compressor and orifice
tube on an OT system.
But when there's a full buildup of black or gray
debris the length of that bag, that was a classic sign
of black death. Going further: step 2 is to disconnect
the refrigerant lines at the compressor and cotton
swab the compressor ports and both line ends for
black-or-gray debris (Figure 7). Finally, swab the end
of the discharge hose and the inlet to the condenser,
and if you get a deposit of debris on them, the hose
and condenser should be replaced, and the expansion
valve, too. And we'll add it 's not a bad idea to
flush the evaporator and install filtering screens on
the liquid line and compressor inlet (Figures 8, 9).
If there's a muffler in a refrigerant line, that also
should be an " automatic " replacement.
The security of a " complete " parts kit (no need
for a technician to think about what to order) led
Four Seasons to introduce its line of PACS kits
and " Super PAC " kits, which are an effort to come
as close as reasonably possible to simplify things.
See Figure 10. No kit we've seen turns out to be
totally complete-there's invariably something additional
that you'll need with most major jobs. But
these " Super PAC " kits include the compressor, can
of oil, expansion valve or orifice tube, receiver-dryer
or equivalent container with desiccant, condenser,
set of O-rings and gaskets, hoses, a refrigerant filter,
Figure 6: This Honda desiccant bag from a " black death "
failure shows a buildup of black debris.
haps a Four Seasons " deslugger. " This is a plug-in
timer device (for certain GM, Ford, Chrysler-Dodge
and Honda) that allows a low-mount compressor to
pump out liquid refrigerant (and some oil) before
cooling starts.
tamper-evident seals for the service valves, and perFigure
5: These three desiccant bags show two levels of
contamination from a " black death " failure of compressor,
including overheated oil at left, gray debris primarily from
compressor parts wear out, and a clean bag at right.
June 2022
5
MACS Service Reports
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MACS Monthly Newsletter - 2022

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