Hitachi DH 40SR Service Manual And Technical Data page 21

(2) Disassembly of the piston and the striker
Remove the Seal Lock Hex. Socket Hd. Bolt M4 x 12 [44] from the Crank Cover [46] then remove the Crank
Cover [46] from the Cylinder Crank Case [56]. Remove the Seal Lock Hex. Socket Hd. Bolt M6 x 45 [43] and
Seal Lock Hex. Socket Hd. Bolt M6 x 22 [89]. Remove the Gear Cover [74] from the Cylinder Crank Case
[56]. Remove the Bevel Pinion [57] (slip clutch) from the Cylinder Crank Case [56] (otherwise, Bevel Gear
[42] cannot be removed later). Remove the Seal Lock Hex. Socket Hd. Bolt M6 x 25 [3] from Front Cover (A)
[9]. Then the tool holder, Driver [13], Driver Holder [12], Damper (B) [11] can be removed from the Cylinder
Crank Case [56]. Remove Oil Seal (B) [14] from the Cylinder Crank Case [56]. At this time, secure the
Cylinder Crank Case [56] and pull out Oil Seal (B) [14] by holding the protrusion with pliers. Remove the
Retaining Ring for D62 Shaft [15] using a retaining ring puller. Then the Hammer Sleeve [21], Cylinder [31],
Second Hammer [23], Slide Sleeve (A) [33], Slide Sleeve (B) [32], Clutch [38], Spring (A) [34], etc. can be
removed from the Cylinder Crank Case [56] in an assembled state. Remove the Bevel Gear [42] from the
Cylinder Crank Case [56] by tapping Front Cover (A) [9] side with a plastic hammer. Remove the Striker [36]
by tapping the Cylinder [31] with a plastic hammer. The Piston [39] remains in the Cylinder Crank Case [56].
Remove the Retaining Ring for D10 Shaft [49] using a retaining ring puller and remove the Connecting Rod
[41] from the Crank Shaft [50] (Fig. 11).
Retaining Ring for
D62 Hole [15]
Hammer
Sleeve [21]
Second Hammer [23]
Oil Seal (B) [14]
Protrusion
Slide Sleeve (A) [33]
Spring (A) [34]
Striker [36]
Slide Sleeve (B) [32]
Cylinder Crank Case [56]
Clutch [38]
Cylinder [31]
Piston [39]
Bevel Pinion [57]
Fig. 11
--- 18 ---
Bevel Gear [42]
Connecting Rod [41]
Crank Shaft [50]