Komatsu WA200-8 Operation & Maintenance Manual page 330

MAINTENANCE PROCEDURE
1.
Start the engine and set the engine speed to approximate-
ly 1500 rpm.
2.
Press the fan switch (1) and set the air flow to "MAX".
3.
Press the temperature adjustment switch (2) and set the
temperature to 18 °C.
4.
Fully open the doors and windows.
5.
Press the air conditioner switch (3) to turn on the air condi-
tioner switch.
6.
Open the engine side cover (4) on the right side of the ma-
chine.
7.
Check the condition of the refrigerant gas (Hydrofluorocar-
bons HFC-134a) that circulates the refrigerant circuit,
through the sight glass (6) (inspection window) of the re-
ceiver drier piping (5).
(A) Just after the air conditioner switch is turned on, a
small number of bubbles are seen. After a while, the
sight glass becomes milky white, and then becomes
pale: Appropriate
(B) After the air conditioner switch is turned on, bubbles
are seen continuously: Insufficient
Condition viewed through the
sight glass
4-38
Bubbles are seen: Gaseous and liquid refrigerants are mixed.
No bubble: All refrigerant becomes liquid and transparent.
State of refrigerant flow
MAINTENANCE