26
General Compressor Repair Techniques
Because of the various refrigeration unit models a
given compressor may be used on, no attempt is
being made in this manual to show a removal
procedure. This manual assumes that the
compressor has been removed properly in
accordance to the maintenance manual for the
appropriate model.
This manual does cover the drive coupling
removal and reinstallation. The illustrations used
are typical, your installation may vary from what
is shown.
Dirt and Moisture can Easily
Ruin Compressors!
Compressors are assembled at the factory in
special clean rooms with filtered, conditioned air.
Field conditions will not always allow factory
clean repair areas but every effort should be taken
to keep the compressor work area as clean as
possible. Follow these rules to protect
compressors from dirt and moisture.
•
Pump down the system and recover the
refrigerant in compliance with Federal, State
and local regulations.
•
Use dry nitrogen to break the vacuum. This
prevents dirt and moisture from getting into
the compressor.
•
Use cap plugs or tape instead of rags to cover
compressor openings as soon as vibrasorbers
or service valves are removed. Poloyol ester
oil draws in moisture like a sponge and rags
will not stop moisture from entering the
compressor.
•
Remove all dirt and debris from the
compressor prior to disassembly.
•
Work in a clean, closed area. Stay away from
open doors or windows that allow dirt to blow
in parts cleaning areas, grinding areas and
bead blasting machines.
•
Keep your tools and workbench spotless.
Keep your hands as clean as possible.
•
Once the compressor is opened to the
atmosphere, get the job done quickly. Plan
ahead. Have your parts and tools ready.
•
Only use chemical solvents that leave no oily
residue, such as naphtha, lacquer thinner, or
brake cleaner to clean compressor
components. The solvents must be
nonchlorinated.
Do Not Bead Blast
compressor components clean.
•
If the job must be interrupted, cover the
compressor. A fresh, clean piece of plastic
sheeting wrapped tightly around the
compressor is best. Cloth should not be used
as it does not block moisture.
•
Be sure to use the correct oil to prevent
contamination of the system.
•
Always keep your refrigeration oil capped. A
few minutes with the cap off can ruin it!
•
Do not dip seal parts in oil. Containers of oil
used for dipping parts sit open and collect
moisture, dirt and dust. Instead, use a small,
clean oil can dedicated for use only with the
correct oil for the compressor you are
repairing.
•
Discard all the old O-rings and gaskets that are
exposed while working on the compressor.
O-rings and gaskets should not be reused.
Replace them with new ones.
Compressor Oil Indications
Discoloration of the oil is an indication of a
contaminated system and future problems. Refer
to the following compressor Oil Color Code to
diagnose the conditions and correct it.
Compressor Oil Color Code
COLORLESS or LIGHT YELLOW. Indicates
good compressor oil.
BLACK OIL. Indicates carbonization caused by
air in the system or the presence of wear particles
that contain iron. Change the compressor oil and
oil filter.
LIGHT BROWN OIL. Use an acid test kit to test
the acidity of a sample of the compressor oil. For
alkyl benzine oil use acid test kit P/N 203-346.
For polyol ester oil use acid test kit P/N 203-518.
Change the compressor oil if the test indicates the
oil is acidic.
