Hitachi DH 24DVA Technical Data And Service Manual page 34

Vise
(6) Removal of the armature and the housing
After disassembly of the hammering mechanism section, remove the Machine Screw M4 x 8 [82] from the
Grip Cover [81] and remove the Grip Cover [81] to show the carbon brushes. Hook the Spring [64] on the
edge of the carbon brush tube. Remove the Tapping Screw (W/Flange) D4 x 16 (Black) [57] from the Inner
Cover Ass'y [42]. Then the Inner Cover Ass'y [42] can be removed together with the Armature and Pinion
Ass'y DC 24 V [60]. At this time, be careful not to damage the carbon brushes. The Inner Cover Ass'y [42]
and the Armature and Pinion Ass'y DC 24 V [60] can be removed just by pressing the Pinion [55] slightly with
a press because there is an interference of the O-ring [58]. The housing is constructed of two parts. Remove
the Tapping Screw (W/Flange) D4 x 20 (Black) [70] to disassemble the housing.
(7) Removal of the carbon brush holder
After disassembly of the housing, remove the Tapping Screw (W/Flange) D4 x 16 (Black) [57] to remove the
carbon brush holder.
(8) Replacement of the carbon brushes
Remove the Grip Cover [81] to show the carbon brushes. Pinch the terminal of the Carbon Brush (Auto Stop
Type) (1 Pair) [66] with a pair of long-nose pliers as shown in Fig. 20 and pull it out of the carbon brush holder.
At this time, melt solder at the terminal. Hook the Spring [64] on the Carbon Brush (Auto Stop Type) (1 Pair)
[66] with a flat-blade screwdriver and remove the Carbon Brush (Auto Stop Type) (1 Pair) [66].
O-ring (1AP-20) [30]
Hammer Holder [31]
Second Hammer [29]
O-ring (B) [32]
Long-nose
pliers
Tap with a hammer.
Punch (C) (J-341)
5-mm diameter hole (2 pcs.)
Damper Holder [35]
Damper (A) [33] Stopper Ring [36]
Stopper ring jig (A) (J-341)
Fig. 19
Terminal
Carbon
Brush [66]
Fig. 20
--- 31 ---
O-ring (C) [34]
Spring [64]
Flat-blade
screwdriver