Komatsu PC400 - Air from Circuit

18. OUTLINES OF SERVICE
18.5 BLEEDING AIR FROM CIRCUIT
When replacing or cleaning the hydraulic oil, filter element, or
strainer, or when replacing or cleaning the line filter element, or
when repairing or replacing hydraulic equipment, or after removing
the hydraulic piping, bleed the air from the circuit.
PROCEDURE FOR BLEEDING AIR
Air bleeding item
Air bleeding procedure
1
2 3
4 5
6
l Change hydraulic oil
0 Clean strainer
l Replace return filter element
o-o-o-o-o-o
‘1 ‘1
0
l O
l Replace, repair pump
l Replace, clean line filter element
o-o-o
.O
l Remove suction piping
l Replace, repair control valve
I
o-o-o-o-o
l Replace cylinder
l Remove cylinder piping
I
o-o
t0
l Replace swing motor
l Remove swing motor piping
l Replace travel motor, swivel
l Remove travel motor, swivel Dioina
0
l O
l O
0
*o ----+o
*1 . Bleed the air from the swing motor and travel motor only when the oil inside the motor case has been drained
a.
1.
2.
l
0
b.
Bleeding air from pump
Loosen the bleeder at portion @, remove plug @I, then add oil
through filler @ to fill the pump with oil.
After completion of bleeding the air, install plug @ first, then
tighten the bleeder.
If the breather is tightened first, oil will spurt out from hole @I.
If the pump is operated without the pump case being filled with
hydraulic oil, abnormal heat will be generated, and this may lead
to premature damage to the pump.
Tightening torque
Bleeder @: 9.0 + 1 Nm (0.9 f 0.1 kgm, 6.5 f 0.7 Ibft)
Plug @:
70 f 10 Nm (7.0 + 1.0 kgm, 51 rt 7 Ibft)
Start engine
Start the engine (see “12.2 STARTING ENGINE”) and run at low
idling for IO minutes, before going on to the next operation.
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