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

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strike the head of the cotter with a manual hammer
supporting on a rest. (Fig. 13)
USING DRILL CHUCK, CHUCK ADAPTER
Note that this machine can be used at "rotation only"
if separately sold parts such as drill chuck and chuck
adapter are attached. Use it with the selector lever
positioned at "rotation + hammering".
CAUTION:
During operation, be sure to grip the handle and the
side handle firmly to prevent your body from swaying.
(1) Switching to "rotation + hammering"
For switching to "rotation + hammering", follow the
same procedures mentioned in [3. When drilling at
"rotation + hammering"].
(2) Attaching chuck adapter to drill chuck (Fig. 14)
(a) Attach the chuck adapter to the drill chuck.
(b) The SDS max shank of the chuck adapter is
equivalent to the drill bit. Therefore, follow the
same procedure as [How to install tool] for
attaching and detaching.
(3) Drilling
(a) Even if you apply more-than-required pressure
to the machine body, drilling can never be
performed as quickly as you expect. Applying
more force or pressure to the machine body
than what is needed, on the contrary, damages
the drill tip, resulting in the declined working
efficiency and shortened life of this machine.
(b) A drill can snap sometimes when drilling is
almost finished.
thrusting pressure when drilling is nearing the
end.
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 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)
33
It is important to relax your
(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 drill (with the core bit inserted) in
an upward position, drive the drill to repeat impact
operation two or three times, whereby the screw
is loosened and the drill becomes ready for
disassembly. (Fig. 19)
Remove the core bit shank from the drill, 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 drill 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.
(1) Remove the crank cover and wipe off the grease
inside. (Fig. 21)
(2) Supply 30 g of Hitachi Electric Hammer Grease A
(Standard accessory, contained in tube) to the crank
case.
(3) After replenishing the grease, install the crank case
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.