Hitachi NR 90AD Technical Data And Service Manual page 28

Push
When disassembling,
do not pull out
this part by gripping
it with the pliers.
Pull out
Wire with 1.5 mm to 3 mm (0.059" to 0.118") dia.
Body Ass'y [24]
Valve Piston [66]
Valve Bushing (A) [71]
Plunger [70]
Fig. 16
Valve Bushing (B) [63]
Holes
Be careful not to damage
the internal surface.
Fig. 17
Pull out the Roll Pins D3 x 25 [20] and
D3 x 32 [21] with the roll pin puller (3 mm
dia.), and take out the control valve in the
following manner.
1) Remove the Exhaust Cover [5] by following
the procedure in (1), item 10-2.
2) As shown in Fig. 16, put in the 4 to 5 mm
(0.157" to 0.197") dia. bar from the upper side
of the Body Ass'y [24] and push the top of
Valve Piston [66]. Now, the parts forming the
control valve can be taken out except Valve
Bushing (B) [63].
[CAUTION]
Be careful not to damage the Valve Piston
[66], Valve Bushings (A) [71] and (B) [63],
etc.
Do not pull out the end of the Plunger [70]
with the pliers.
3) To take out Valve Bushing (B) [63], put a 1.5 to
3 mm (0.059" to 0.118") dia. wire with its end
hooked into the hole in the bushing and pull it
out while being careful not to damage the
internal surface of Valve Bushing (B) [63], as
shown in Fig. 17.
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