GENERAL INFORMATION / Precautions for Disassembling and Assembling
W1-1-2
Bleeding Air from Hydraulic System
When hydraulic oil is drained, the suction filter or the
suction lines are replaced, or the removal and instal-
lation of the pump, swing motor, travel motor or cylin-
der is done, bleed air from the hydraulic system in the
following procedures:
•
Bleeding Air from Hydraulic Pump
IMPORTANT: If the engine is started with air
trapped in the hydraulic pump hous-
ing, damage to the pump may result.
Be sure to bleed air before starting
the engine.
•
Remove the air bleeding plug from the top of the
pump and fill the pump housing with hydraulic oil.
•
After the pump housing is filled with hydraulic oil,
temporarily tighten the plug. Then, start the en-
gine and run at slow idle speed.
•
Slightly loosen the plug to bleed air from the pump
housing until hydraulic oil oozes out.
•
After bleeding all the air, securely tighten the plug.
•
Bleeding Air from Travel Motor / Swing Motor
•
With the drain plug (upper side) / hose on travel
motor / swing motor removed, fill the motor case
with hydraulic oil.
•
Bleeding Air from Hydraulic Circuit
•
After refilling hydraulic oil, start the engine. While
operating each cylinder, swing motor and travel
motor evenly, operate the machine under light
loads for 10 to 15 minutes. Slowly start each op-
eration (never fully stroke the cylinders during ini-
tial operation stage). As the pilot oil circuit has an
air bleed device, air trapped in the pilot oil circuit
will be bled while performing the above operation
for approx. 5 minutes.
•
Reposition the front attachment to check hydraulic
oil level.
•
Stop the engine. Recheck hydraulic oil level. Re-
plenish oil as necessary.
M104-07-021
