Hitachi NV 75AG Technical Data And Service Manual page 23

Air leakage portion
(A) Exhaust port
(B) Exhaust cover
(C) Nose 1
(Feed piston passage)
(D) Nose 2
(E) Feed piston
(F) Control valve 1
When the Trigger is turned off
Abnormality in Head Valve (A) [10]
and Cylinder [15] [Wear and
deformation of the sealed face of the
(b) section]
Abnormality in Head Valve O-ring
(P-22) [9] or wear, deformation and/
or breakage of Head Valve (A) [10]
Abnormality (damage) in the Exhaust
Cover [5]
Looseness of the Hex. Socket Hd.
Bolt M5 x 35 [4]
Damage of Gasket (B) [6]
Abnormality in the sealed face of the
Body [18], the Exhaust Cover [5] and
the Cylinder [15]
* Abnormality (breakage and/or
scratches) in O-Ring (S-70) [11] of
the Cylinder Plate [12]
Abnormality in the sealing faces [the
sections (c) and/or (d)] of the
Cylinder Plate [12], Body [18] and/or
the Cylinder [15]
Abnormality (wear, breakage and/or
scratches) in O-ring (S-4) [48] of
Valve Piston (B) [57]
Abnormality (wear, breakage and/or
scratches) in O-ring (I.D 8.8) [55]
(lower side) of Valve Piston (B) [57]
Abnormality (breakage and/or
scratches) in O-ring (S-18) [54] of
Valve Bushing (B) [53]
* Abnormality in the inner face [the
section (h)] of the valve chamber of
the Body [18]
Cause
When the Trigger is turned on
Abnormality in Head Valve (A) [10]
[Wear, deformation and/or breakage
of the section (a)]
* Abnormality in the inner face [the
section (a)] in the Exhaust Cover [5]
[Deformation and dust clogging in
the section (a)]
Looseness of the Nylock High
Tension Bolt M6 x 20 [23]
Scratched and/or the broken O-ring
(P-4) [21]
Abnormality in the sealed faces of
the Body [18] and the Nose [22]
Abnormality [deformation, crack
and/or damage of the sections (e)
and (f)] in the Piston Bumper [20]
Deformation of Piston (H) [17]
(The deformation of driver blade
abnormality in sealed faces)
The deformation of the face (f) of the
Body [18]
Abnormality (wear, deformation,
breakage and/or scratches) in
O-Ring (S-46) [13]
Abnormality (wear, breakage and/or
scratches) in O-ring (P-21) [63] of the
Feed Piston [64], or the wear and/or
deformation of the Nose [22] on the
sliding face
Abnormality (wear, breakage and/or
scratches) in O-ring (P-9) [62] of the
Nose [22], or wear, deformation
and/or scratches of the Feed Piston
[64] on the sliding face
Abnormality (wear, breakage and/or
scratches) in O-ring (I.D 8.8) [55]
(upper side) of Valve Piston (B) [57]
Abnormality (breakage and/or
scratches) in Head Valve O-ring (I.D
16.8) [52] of Valve Bushing (B) [53]
* Abnormality in the upper face [the
section (g)] of the valve chamber of
the Body [18]
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