Komatsu 830E, Руководство по ремонту

Страница: 565 / 783

M09010 05/02 Air Conditioning System M9-9
for HFC 134a Refrigerant
SYSTEM OIL
R-134a air conditioning systems require the use of
polyalkylene glycol (PAG) lubricating oil. This is the
only oil recommended for use in this system. At
present time, General Motors part number (12345923)
is the oil that is furnished in the system on Komatsu
trucks. This clear oil can be found at AC Delco dealers.
In some areas, it can be found from other suppliers as
U-Con 488. The only other alternative is General
Motors part number (12356151) which is now becom-
ing more popular and is expected to become the fur-
nished oil in Komatsu AC systems. This oil is light blue-
green in color and may be mixed with the other recom-
mended oil.
Handling and Reusing PAG Oil
•Avoid skin contact and inhalation of PAG oil, as
these are normal precautions with any chemical.
•No PAG oil removed from new or old components
should be retained for re-use. It should be stored
in a marked container and properly sealed. PAG
oil is an environmental pollutant and should be
properly disposed of after use.
•
PAG oil in containers or in an air conditioning sys-
tem should not be left exposed to the atmosphere
any longer than necessary. PAG oil absorbs mois-
ture very rapidly, and therefore, any
absorbed
moisture could cause damage to an air condition-
ing system.
OIL QUANTITY
It is critical to keep the correct amount of lubricant in
the air conditioning system at all times. Failure to do so
could result in damage to the compressor.
Damage to the compressor can be a result from not
only a lack of oil, but from too much oil, also. A lack of
oil will cause excess friction and wear on moving parts.
Excessive oil can result in “slugging” the compressor.
This condition occurs when the compressor attempts to
compress liquid oil as opposed to vaporized refriger-
ant. Since liquid cannot be compressed, damage to
internal parts results.
Replacing Oil After Servicing the System
Replace oil that has been removed from the system
through recovery of refrigerant and replacement of
components. Refer to the chart below for adding oil.
Setting Up a New Compressor
Compressors come with 10.5 ounces of oil in the
sump. Compressors being replaced should have been
operating with 6 ounces of oil in the sump, therefore,
the new compressor should be adjusted, accordingly.
Example: If a compressor is being replaced, the
receiver drier must also be replaced. (The receiver-
drier should be replaced whenever the system is
opened.) Since the new compressor comes with 10.5
ounces of oil, 2.5 ounces of oil should be removed from
the compressor leaving 8 ounces. 8 ounces accounts
for the 6 ounces needed for the compressor, and the 2
ounces for the new receiver-drier.
Never run the system with more than 10.5 ounces
of oil in the compressor sump. Damage to the com-
pressor as well as other system components may
occur. It is important to have a good balance of oil
throughout the system.
REPLACING OIL
Component Oil to add
Condenser 2-3 ounces
Evaporator 1 ounce
Receiver-Drier 2 ounces
Compressor
Compressors come with 10.5
ounces of oil in the sump. Refer to
"Setting Up a New Compressor"
Block Valve
(Expansion)
Adding oil is not necessary
Hoses
Drain and measure amount
removed