Hitachi NV 65AF3 Technical Data And Service Manual page 31

(b) Reassembly
Disassembly procedures should be followed in the reverse order. Note the following points.
Reassembly of the control valve section
Pay special attention not to get foreign matter in the control valve section.
Apply grease sufficiently to the O-ring (I.D 1.8) [74] of Plunger (A) [73], O-ring (S-4) [55] and O-ring (I.D 8.8)
[69] of Valve Piston (B) [70].
Mount Valve Bushing (A) [75] so that the roll pin groove of Valve Bushing (A) [75] aligns with the roll pin hole
of the Body [23]. Insert a roll pin puller (3 mm dia.) to check that it is put through the roll pin hole, then drive
the Roll Pin D3 x 28 [60] and the Roll Pin D3 x 22 [59].
If the roll pins are driven forcedly in spite of the roll pin groove of Valve Bushing (A) [75] does not align
with the roll pin hole of the Body [23], the outside of Valve Bushing (A) [75] will be damaged, and
disassembly and reassembly will be impossible.
Body [23]
Roll pin
groove
After reassembly, check that Plunger (A) [73] moves smoothly.
Reassembly of the trigger unit
Trigger Arm (B) [43]
Trigger [45]
Roll pin hole
Roll pin groove
Valve Bushing (A) [75]
Protrusion of Trigger Arm (B) [43]
Roll Pin D2.5 x 16 [44]
Spring [42]
Fig. 21
Seal grease in the
O-ring groove.
Roll Pin D3 x 28 [60]
Valve Bushing (A) [75]
Fig. 20
Mount Trigger Arm (B) [43] facing its
protrusion upward (Fig. 21).
Mount the Roll Pin D2.5 x 16 [44] facing its
split downward.
Trigger Piece [41]
--- 28 ---
Apply grease
to the groove.
Roll Pin D3 x 22 [59]
Plunger (A) [73]