16
English
MAINTENANCE AND INSPECTION
WARNING: Be sure to switch power OFF and disconnect the plug from the receptacle during maintenance
and inspection.
1.
Inspecting the drill bits
Since use of a dull tool will cause motor
malfunctioning and degraded efficiency, replace the
drill bit with a new one or resharpening without
delay when abrasion is noted.
2. Inspecting the screws
Regularly inspect all screws and ensure that they
are properly tightened. Should any of the screws
be loosened, retighten them immediately.
WARNING: Using this rotary hammer with
loosen screws is extremely
dangerous.
3. 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.
4. Inspecting the carbon brushes: (Fig. 31)
The motor employs carbon brushes which are
consumable parts. When they become worn to or
near “wear limit”, it could result in motor trouble.
At that time, replace both carbon brushes with new
ones which have the same carbon brush Nos.
shown in the figure.
In addition, always keep carbon brushes clean and
ensure that they slide freely within the brush
holders.
CAUTION:
Using this rotary hammer with a
carbon brush which is worn in
excess of the wear limit will damage
the motor.
NOTE:
Use HITACHI carbon brush No.04 indicated in
Fig. 31.
䡬
Replacing carbon brushes:
(For parts name, refer to Fig. 1)
Loosen the two set screws and remove the tail
cover. Remove the brush caps and carbon brushes.
After replacing the carbon brushes, tighten the
brush caps securely and to install the tail cover with
securely tightening two set screws.
5. How to replase grease
This machine is full air-tight construction to protect
against dust and to prevent lubricant leakage.
Therefore, the machine can be used without
lubrication for long periods. Replace the grease as
described below.
䡬
Grease replacement period
You should look at the grease when you change
the carbon brush. (See item 4 in the section
MAINTENANCE AND INSPECTION.) Ask for grease
replacement at the nearest HITACHI Authorized
Service Center. Proceed for replacement of grease.
䡬
Grease replenishment
CAUTION:
Before replenishing the grease, turn
the power off and pull out the
power plug.
(1) Disassemble the crank case cover and thoroughly
wipe off the old grease inside. (Fig. 32)
(2) Supply 1.0 oz (30g) of Hitachi Electric Hammer
Grease A (standard accessory, contained in tube)
in the crank case.
(3) After replacing the grease, reassemble the crank
case cover securely. At this time, do not damage or
lose the oil seal.
NOTE:
The HITACHI Electric Hammer Grease A
is of the lower viscosity type. When the
supplied grease tube is consumed,
purchase from a HITACHI Autorized
Service Center.
Wear limit
No. of carbon brush
0.24" (6 mm)
0.67" (17 mm)
04
Fig. 31
01Eng_DH28PD_US
5/28/10, 2:57 PM
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