Method For Bleeding Air From Hydraulic Circuit - Komatsu WA600-8 Operation & Maintenance Manual

MAINTENANCE PROCEDURE
1.
Start the engine and set the engine speed to approximate-
ly 1500 rpm.
2.
Press fan switch (1) and set the air flow to "Hi".
3.
Press temperature adjustment switch (2) and set the tem-
perature to 18 °C.
4.
Fully open the doors and windows.
5.
Press air conditioner switch (3) to turn the air conditioner
switch ON.
6.
Open radiator guard side cover (4) on the right side of ma-
chine, and fix it with the rod.
7.
Check the condition of the refrigerant gas (Hydrofluorocar-
bons HFC -134a) that circulates the refrigerant circuit,
through sight glass (6) (inspection window) of air condition-
er hose (5).
(a) in the figure shows that the refrigerant gas is appropri-
ate state when seeing the condition through sight glass.
(b) in the figure shows that the refrigerant gas is insuffi-
cient state when seeing the condition through sight glass.
Ask your Komatsu distributor for refilling with the refriger-
ant gas.
A: Quantity of refrigerant
B: Condition viewed through sight glass
a: Appropriate: Just after the air conditioner switch is
turned on, a small number of bubbles are seen. Then,
the sight glass becomes milky white, and then becomes
pale.
b: Insufficient: After the air conditioner switch is turned on,
bubbles are seen continuously.
X: State of refrigerant flow
Y: Condition viewed through sight glass
x: Bubbles are seen: Gaseous and liquid refrigerants are mixed.
y: No bubble: All refrigerant becomes liquid and transparent.
z: Milky white: Oil and refrigerant are separated and their mixture is milky white.
8.
After checking the quantity of refrigerant, release the lock of radiator guard side cover (4) and close the
cover.

METHOD FOR BLEEDING AIR FROM HYDRAULIC CIRCUIT

Bleed air from the hydraulic circuit after the oil, filter element or strainer, etc. has been replaced or cleaned.
After the oil in hydraulic tank or element is changed, or the hydraulic cylinder or piston pump is removed, or the
work equipment or piston pump piping is removed, perform the following in order to bleed the air.
Bleed the air from piston pump first and then bleed the air from cylinder.
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MAINTENANCE