Hitachi H 70SA Technical Data And Service Manual page 20

Mounting of Oil Seal (A) [25]
When mounting Oil Seal (A) [25] on the Piston [26], ensure
that the lip portion of the Oil Seal is directed toward the rear
surface of the Piston [26], as illustrated in Fig. 12. Prior to
reassembly, thoroughly coat Oil Seal (A) [25] and O-Ring (A)
[24] with grease (Grease for Impact Drill, Part No. 980927 or
981840 or 308471 is recommended), and carefully ensure they
are not damaged.
Mounting of Seal Ring (A) [38]
To prevent oil from leaking through between the Housing Ass'y [104] and the Inner Cover [37], Seal Ring (A)
[38] is installed in the Inner Cover [37] for sealing grease. When fitting Seal Ring (A) [38] in the ring groove
on the Inner Cover [37], exercise care not to allow the Seal Ring (A) [38] to twist or project out of the groove.
Reassembly of the Stop Lever [2]
Prior to reassembly, thoroughly coat the grease
(Doubrex 251, Part No. 980757, is recommended) on
the sliding portion of the Stop Lever [2]. As illustrated
in Fig. 13, place the end surface of the Stop Lever [2]
on the flange portion of the Front Cover [7] and
compress the Lever Spring [5] by pressing the Damper
(B) [6] with two slender minus screwdrivers. Then,
align the holes of the Stop Lever [2] and the Spring
Case [4], and insert the Needle Roller [3].
9-1-3. Screw Locking Agent TB1401
(1) Prior to reassembly, all M5, M6 hexagon socket hd. bolts and machine screws must be coated with screw
locking agent TB1401.
(2) The following parts must be replaced with new Hitachi genuine parts if they are loosened once.
Front cover fixing bolts: Nylock Hex. Socket Hd. Bolt M8 x 30 [10]
Cylinder case fixing bolts: Nylock Hex. Socket Hd. Bolt M8 x 35 [22]
Fixing bolt on the Connecting Rod Ass'y [28] and Handle Holder [48]: Seal Lock Hex. Socket Hd. Bolt M8 x 16 [31]
[CAUTION] If fastening bolts come loose from vibration, it could cause serious damage to the machine.
Ensure without fail that TB1401 screw locking agent is applied as directed above prior to
reassembly. Before applying the TB1401, carefully clean any grease or other foreign matter
from the male and female threads with gasoline, thinner or similar cleaning solvents.
O-Ring (A) [24]
Spring Case [4]
Needle Roller [3]
Stop Lever [2]
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Oil Seal (A) [25]
Lip
Piston [26]
Fig. 12
Damper (B) [6]
Lever Spring [5]
Fig. 13