How To Replace Grease; Maintenance And Inspection - Hitachi DH 40MR Handling Instructions Manual

English
HOW TO HANDLE A CORE BIT
When a core bit is used, large diameter holes and blind
holes can be drilled. In this case, use optional
accessories for core bits (such as a center pin and core
bit shank) for more efficient operation.
1. Mounting
CAUTION
Prior to mounting a core bit, always disconnect the
plug from the power supply receptacle.
(1) Mount the core bit on the core bit shank. (Fig. 15)
Before that, feed oil to the screw portion of core
bit shank for easy dismounting.
(2) Mount the core bit shank on the main body in the
same manner as in mounting the drill bit and the
bull point. (Fig. 16)
(3) Insert the center pin into the guide plate until it
reaches the extremity.
(4) Fit in the guide plate by aligning its concaved
portion with the core bit tip. When the position of
the concave is shifted by turning the guide plate
right or left, the guide plate never slips off even
when the drill is used in a downward direction.
(Fig. 17)
2. Drilling holes
(1) Insert the plug into a receptacle.
(2) A spring is built in the center pin. By straightly and
gently pressing it to the wall or floor surface, the
entire surface of the core bit tip attains contact to
start the hole drilling job. (Fig. 18)
(3) When the hole depth reaches approximately 5 mm,
the hole position can be determined. Then remove
the center pin and guide plate from the core bit
and continue the hole drilling job.
CAUTION
When removing the center pin and guide plate,
always disconnect the plug from the receptacle.
3. How to dismount the core bit
By holding the rotary hammer (with the core bit
inserted) in an upward position, drive the rotary
hammer to repeat impact operation two or three
times, whereby the screw is loosened and the rotary
hammer becomes ready for disassembly. (Fig. 19)
Remove the core bit shank from the rotary hammer,
hold the core bit with one hand, and strongly strike
the head of the SDS max shank portion of the core
bit shank with a manual hammer two or three
times, whereby the round head screw is loosened
and the rotary hammer is ready for disassembly.
(Fig. 20)

HOW TO REPLACE GREASE

This machine is of 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.
1. Grease replacement period
After purchase, replace grease after every 6 months
of usage. Ask for grease replacement at the nearest
Hitachi authorized Service center. Proceed for
replacement of grease.
2. Grease replenishment
CAUTION
Before replenishing the grease, turn the power off
and pull out the power plug.
9
(1) Remove the crank cover and wipe off the grease
inside. (Fig. 21)
(2) Supply 30g of Hitachi Electric Hammer Grease A
(Standard accessory, contained in tube) to the crank
case.
(3) After replenishing the grease, install the crank cover
securely.
NOTE
The Hitachi Electric Hammer Grease A is of the low
viscosity type. If necessary purchase from an Hitachi
authorized Service center.

MAINTENANCE AND INSPECTION

1. Inspecting the tool
Since use of a dull tool will degrade efficiency and
cause possible motor malfunction, sharpen or
replace the tool as soon as 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. 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. 22)
The Motor employs carbon brushes which are
consumable parts. When they become worn to or
near the "wear limit", it could result 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 Numbers shown in the figure.
In addition, always keep carbon brushes clean and
ensure that they slide freely within the brush holders.
5. Replacing carbon brushes
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 install the tail cover with securely
tightening two set screws.
6. Service parts list
A: Item No.
B: Code No.
C: No. Used
D: Remarks
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.
MODIFICATIONS
Hitachi Power Tools are constantly being improved
and modified to incorporate the latest technological
advancements.
Accordingly, some parts (i.e. code numbers and/or
design) may be changed without prior notice.