Hitachi EX20UR-2 Manual page 78

UPPERSTRUCTURE / Control Valve
Disassemble Pilot Pressure-Type Spool
(Offset (only in EX3OUR-2, EX4OUR-2), Boom,
Bucket, Arm, Swing)
1. Remove socket bolts (7), cover (17), and 0-ring
(19).
r" . " : 4 mm (EX20UR-2)
5 mm (EX3OUR-2, EX4OUR-2)
2. Remove spool (23) with socket bolt (20). Spring
seats (21) and spring (22) are also removed at
this time.
3. Sandwich spool (23) between wooden plates,
and clamp in a vise.
Remove socket bolt (20), spring seats (21) (2
used), and spring (22) from spool (14).
: 4 mm (EX3OUR-2)
5 mm (EX2OUR-2, EX4OUR-2)
The illustration shows the swing valve
section of the EX3OUR-2 control valve.
A
CAUTION: Socket bolt (20) and spring
seat (21) may fly off by the force of spring
(22) when removing socket bolt (20). Pre-
vent personal injury by holding down
spring seat (21) and spring (22) by hand
while slowly loosening socket bolt (20).
W506-02-05-002
1— Body
17— Cover (2 used)
20— Socket Bolt
22— Spring
7— Socket Bolt (4 used)
19— 0-ring (2 used)
21— Spring Seat (2 used)
23— Spool
W02-04-14