Maintenance And Inspection - Hitachi H 90SB Handling Instructions Manual

Grease Replacement Period:
After purchase, replace grease after every 6 months of usage.
Ask for grease replacement at the nearest authorized service center.

MAINTENANCE AND INSPECTION

1. Inspecting this Demolition Hammer
Use of a dull accessory, such as a bull point, a cutter, etc., will cause motor
malfunctioning and efficiency degraded. Replace with a new one without delay when
abrasion is noted.
2. 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 could
result in serious hazard.
3. Inspecting the retainer (Fig. 2 and 3)
The retainer may become loose due to excessive use. Always, pay attention to its proper
functioning to securely hold the accessory shank portion. If any wear and tear is found,
bring this Demolition Hammer to an authorized service center for maintenance service.
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. 4)
The motor employs carbon brushes which are consumable parts. When they become
worn to or near "wear limit", it results in motor trouble. When an auto-stop carbon
brush is equipped, the motor will stop automatically. At that time, replace both carbon
brushes with new ones which have the same carbon brush Nos. shown in the Fig. 4.
In addition, always keep carbon brushes clean and ensure that they slide freely within
the brush holders.
Wear limit
6. Replacement procedure
Loose the screw (Hexagon socket hd. bolt M5 x 10) of the tail cover, then remove the
tail cover. (Fig. 1) After removing the brush cap, the carbon brush can be removed.
After replacing the carbon brush, tighten the brush cap, then mount the tail cover
securely.
NOTE:
Due to HITACHI's continuing program of research and development, the specifications herein
are subject to change without prior notice.
No. of Carbon
Brush
Fig. 4
Usual carbon brush
Auto-stop carbon
brush
No. of
a
carbon brush
44 6
74 7
6