Hitachi NR 83A2, Technical Data And Service Manual

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Cylinder [17] does not return.
Swollen Cylinder O-ring [16] (Use of
unsuitable oil causes swelling.  Advise the
customer to use Shell Tonna Oil T32.)
Deformed Cylinder [17] or Cylinder Guide [22].
Yielded or broken Cylinder Spring [20].
Defective Head Cap and Gasket Set [10]
(worn rubber portion or broken)
Broken Gaskets (C) (F) [8] [6]
Loose Hex. Socket Hd. Bolt (W/Flange)
M6 x 45 [1]
Broken Exhaust Cover [4]

Loose Hex. Socket Hd. Bolt (W/Sp. Washer)
M6 x 25 [3]
Broken Gasket (B) [5]
Damaged seal surfaces of Body Ass'y [25]
and Exhaust Cover [4]

Damaged Cylinder O-ring [18] or O-ring of
Cylinder Guide [22] (worn, deformed or
broken)
Defective Body Ass'y [25] (worn, corroded or
deformed)

Defective Urethane Ball (C) D7.14 [62]
(damaged or deformed)
Defective ball sheet surface of Trigger Valve
Bushing [65] (damaged, deformed or worn)
Defective Valve Packing [61] (damaged,
deformed or broken)
Soiled or damaged valve packing sheet
surface of Body Ass'y [25]
Incursion of foreign materials

Defective Gaskets (C) (F) [8] [6] (damaged
or yielded)
Deformed or broken Gasket (G) [23]
Defective O-ring [13] or Cylinder O-ring [14]
of the Cylinder Plate [15] (worn, deformed or
broken)
Defective Cylinder O-ring [16] (worn,
deformed or broken)

Defective Exhaust Valve
[9] (worn, deformed, or
broken)

Exhaust vent

Air leak part

Cause

When trigger valve/safety valve are OFF

When trigger valve/
safety valve are ON

Inspection priorities:

In the table below, possible causes of air leakage and their repair procedures are marked in accordance with the

likelihood of possible failure.

(1) First priority items are marked with an asterisk (   ).

(2) Second priority items (seal portions) are marked with a double circle (    ).

(3) Remaining items are marked with a single circle (    ).  (See Parts List and exploded assembly diagram for part

name and location.)

Deformed Nose [32]
Loose Nylock Hex. Socket
Hd. Bolt M8 x 22 [33]
Damaged Gasket (A) [28]

When trigger valve ON/
safety valve OFF

A

Exhaust cover

B

Nose

C

Nose

D

Trigger valve

E

Safety valve

F

Air will leak slightly from
the lower portion due to
construction.

Defective Plunger O-ring
[67] (worn, deformed or
broken)
Defective outside
O-ring [58] of trigger
Valve Bushing [57]
(When contact actuation
is selected)

Broken or cracked
Piston Bumper (B) [27]
Deformed Piston [12]
Deformed Nose [32]

Scratched or damaged
O-ring [58] outside the
Valve Bushing [57] and
the Plunger O-ring [71]
inside the Valve Bushing
[57]
Valve Bushing [57]
Defective plunger O-ring
[67] (worn, deformed or
broken)
Defective Plunger Spring
[54] (deformed or broken)
Defective Valve Bushing
[57] (deflected, deformed
or broken)

Improperly mounted or
damaged Gasket (G) [23]
Scratched or damaged
O-ring [58] outside the
Valve Bushing [57] at the
safety valve portion
(When single actuation is
selected)