DOC-20230111-WA0038.

FRONT ATTACHMENT / Front Attachment
REMOVE AND INSTALL FRONT ATTACH-
MENT
CAUTION: Escaping fluid under pressure
can penetrate the skin, causing serious injury.
Avoid this hazard by relieving pressure
before disconnecting hydraulic lines.
Hydraulic oil may be hot after operation and
may spurt, possibly causing severe burns. Be
sure to wait for oil to cool before starting any
repair work.
The hydraulic oil tank cap may fly off due to
remaining pressure if removed quickly.
Slowly loosen the cap to release any
remaining pressure completely.
Preparation
1. Park the machine on a solid level surface. Fully
retract the arm and bucket cylinder and lower the
front attachment onto the ground.
2. Stop the engine. Push the air release valve on the
hydraulic oil tank to release any pressure
remaining in the hydraulic tank.
CAUTION: The overload relief valve may
spurt hydraulic oil if loosened more than 3/4
turns. Never loosen the valve further.
IMPORTANT: Be sure to loosen overload relief
valve body.
If the lock nut or adjusting screw is
loosened, pressure setting will
change. Never attempt to loosen
them.
3. Put matching marks on the overload relief valve
and the control valve. Gradually loosen the
overload relief valve to relieve any pressure
remaining in the circuit.
: 24 mm
: 49 to 54 N⋅m (5 to 5.5 kgf⋅m)
Overload Relief
Valve
Upper: Boom Raise
Overload Relief
Valve
Lower: Boom
Lower
Overload Relief Valve
Upper: Bucket Roll-
Out
Lower: Bucket Roll-In
W554-04-02-006
Overload
Relief Valve
Upper: Arm
Roll-Out
Overload
Relief Valve
Lower: Arm
Roll-In
4. Remove the hydraulic oil tank cap. Connect a
vacuum pump and operate it continuously to
maintain negative pressure in the hydraulic oil
tank.
NOTE: Run the vacuum pump continuously while
working on the hydraulic system.
Lock Nut
W1CC-02-05-002
Adjusting
Screw
T152-05-04-003
W4-1-1