Komatsu 830E Shop Manual page 589

PROBLEM: Compressor Malfunction
Indications:
Low side pressure - HIGH
High side pressure - LOW
Compressor operates noisily.
Possible Causes
- Defective reed valves or other internal
components.
PROBLEM: Thermostatic Switch Malfunction
Indications:
Low side pressure - Normal
High side pressure - Normal
Low side pressure may cycle within a smaller
range as the compressor clutch cycles
more frequently than normal. This may indicate
the thermostat is set too high.
Possible Causes
- Thermostat malfunctioning possibly due to
incorrect installation.
M09010 05/02
Repair Procedure: If the belt is worn or loose,
replace or tighten it and recheck system perform-
ance and gauge readings. If inspection of the
compressor is required, all of the refrigerant must
be recovered and the compressor disassembled
to the point that inspection can be performed.
Replace defective components or replace the
compressor. If particles of desiccant are found in
the compressor, flushing of the system will be
required. It will also be necessary to replace the
receiver-drier. Always check the oil level in the
compressor, even if a new unit has been installed.
Rotary compressors have a limited oil reservoir.
Extra oil must be added for all truck installations.
Tighten all connections and evacuate the system.
Recharge the system with refrigerant using a scale.
Check system operation and performance.
Replace the thermostatic switch. When removing
the old thermostat, replace it with one of the same
type. Take care in removing and handling the
thermostat and the capillary tube that is attached
to it. Use care not to kink or break the tube.
Position the new thermostat capillary tube at or
close to the same location and seating depth
between the evaporator coil fins as the old one.
Connect the electrical leads
Air Conditioning System
for HFC 134a Refrigerant
Suggested Corrective Actions
Suggested Corrective Actions
M9-33