Case 580SR Service Manual page 826

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OIL RETAINED IN SYSTEM COMPONENTS
After replacement of individual system components it
will be necessary to add some oil to the system to
make up the amount lost in the removed component.
The table below shows some typical volumes for the
components. It is, however, still recommended that
the oil level measurement, described previously is
carried out after a new component has been installed
to establish correct oil quantity.
Component
Accumulator
Evaporator
Condenser
Receiver dryer
Hoses
Preliminary Inspection
1. Rotate the compressor shaft. Use a suitable
socket on the hub centre bolt or by hand using
the rubber dampers.
If severe roughness is felt while rotating the hub,
the compressor should be disassembled.
2. Using a 12 V battery, test the current absorption
of the field coil: it must be between 3.6 and 4.2 A.
Very high current readings indicate a short cir-
cuit in the field coil and no current reading indi-
cate an open circuit. Replace coil with either
fault. Resistance of the coil using an ohmmeter
should be approximately 3.0 Ω at 20 °C.
A poor ground connection of the field coil will re-
sult in a low voltage.
3. Ensure clutch is disengaged and rotate pulley by
hand. If roughness in the bearing is felt, it will be
necessary to replace the pulley and bearing as
an assembly.
SECTION 50 - CAB HEATING AND AIR CONDITIONING
Typical oil amount
fl.oz. cc
2.0 60
2.0 60
1.0 30
0.5 15
0.3 10
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