English
Bolt
Nut
MAINTENANCE AND INSPECTION
1. Inspecting the driver bit (WH12DM2)
Using a broken bit or one with a worn out tip is
dangerous because the bit can slip. Replace it.
2. Inspecting the socket (WR12DM2)
A worn or deformed hex or a square-holed socket
will not give an adequate tightness to the fitting
between the nut or anvil, consequently resulting in
loss of tightening torque. Pay attention to wear of a
socket holes periodically, and replace with a new one
if needed.
3. Inspecting the mounting screws
Regularly inspect all mounting screws and ensure
that they are properly tightened. Should any of the
screws be loose, retighten them immediately. Failure
to do so may result in serious hazard.
4. Maintenance of the motor
The motor unit winding is the very "heart" of the
power tool.
Exercise due care to ensure the winding does not
become damaged and/or wet with oil or water.
5. Inspecting the carbon brushes (Fig. 18)
The motor employs carbon brushes which are
consumable parts. Since and excessively worn carbon
brush can result in motor trouble, replace the carbon
brush with new ones when it becomes worn to or
near the "wear limit". In addition, always keep carbon
brushes clean and ensure that they slide freely whthin
the brush holders.
NOTE:
When replacing the carbon brush with a new one, be
sure to use the Hitachi Carbon Brush Code No. 999054.
6. Replacing carbon brushes
Take out the carbon brush by first removing the
brush cap and then hooking the protrusion of the
15
Steel plate thickness t
kgf·cm
N·m
M16 × 55 F10T (tighening time 3 sec)
2000
200
1600
160
When full recharged
1200
120
When completely
800
80
discharged
400
40
0
0
0
20
40
Number of tightenings (PCS)/charging
*The following bolt is used.
Ordinary bolt: Strength grade 4.8
High tensile bolt: Strength grade 12.9
(
Explanation of strength grade:
4 — Yield point of bolt: 32 kgf/mm
8 — Pulling strength of bolt: 40 kgf/mm
Fig. 24
a
60
80
100
120
Fig. 25
carbon brush with a slotted head screw driver, etc.,
as shown in Fig. 20.
When installing the carbon brush, choose the direction
so that the nail of the carbon brush agrees with the
contact portion outside the brush tube. Then push it
in with a finger as illustrated in Fig. 21. Lastly, install
the brush cap.
CAUTION:
Be absolutely sure to insert the nail of the carbon
brush into the contact portion outside the brush tube.
(You can insert whichever one of the two nails
provided.)
Caution must be exercised since any error in this
operation can result in the deformed nail of the carbon
brush and may cause motor trouble at an early stage.
7
Cleaning of the outside
When the impact driver is stained, wipe with a soft
dry cloth or a cloth moistened with soapy water. Do
not use chloric solvents, gasoline or paint thinner, as
they melt plastics.
8. Storage
Store the impact driver in a place in which the
temperature is less than 40°C, and out of reach of
children.
9. Service parts list
CAUTION
Repair, modification and inspection of Hitachi Power
Tools must be carried out by an Hitachi Authorized
Service Center.
This Parts List will be helpful if presented with the
tool to the Hitachi Authorized Service Center when
requesting repair or other maintenance.
In the operation and maintenance of power tools, the
safety regulations and standards prescribed in each
country must be observed.
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