Hitachi H90SE Manual

POWER TOOLS
TECHNICAL DATA
AND
SERVICE MANUAL
HAMMER
H 90SE
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST No. E456 Apr. 2000
H
MODEL
H 90SE

Page
CONTENTS
1. PRODUCT NAME••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••1
2. MARKETING OBJECTIVE•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••1
3. APPLICATIONS•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••1
4. SELLING POINTS••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••1
4-1. Selling Point Descriptions•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••2
5. SPECIFICATIONS••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••4
5-1. Optional Accessories•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••5
6. COMPARISONS WITH SIMILAR PRODUCTS••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••7
6-1. Specification Comparisons ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••7
6-2. Demolition Performance Comparisons••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••8
7. PRECAUTIONS IN SALES PROMOTION••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••9
7-1. Handling Instructions•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••9
7-2. Caution Plate•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••9
7-3. Grease Replacement•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••10
7-4. O-Ring Replacement•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••10
8. REFERENCE INFORMATION •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••11
8-1. Air Damper•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••11
8-2. Sealed and Dustproof Construction•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••11
8-3. Vibration-Absorbing Construction•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••12
8-4. Tool Retainer•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••14
9. REPAIR GUIDE ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••15
9-1. Precautions and Suggestions for Disassembly and Reassembly of the Main Body••••••••••••••••••••••15
10. STANDARD REPAIR TIME (UNIT) SCHEDULES••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••23
[ Appendix ]
Assembly Diagram for H 90SE••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••24
Notice for use
Specifications and parts are subject to change for improvement.
Refer to the Hitachi Power Tool Technical News for further information.

--- 1 ---
1. PRODUCT NAME
Hitachi Electric Hammer, Model H 90SE
2. MARKETING OBJECTIVE
The Model H 90SE is a grease-sealed and double-insulated electric hammer. It has a tool retainer that permits
the use of three types of 28.5 mm (1-1/8") hexagonal shank hammer accessories (ie: collar, collar & groove and
groove types). The Model H 90SE has been developed based on the current Model H 90SC, which features the
use of Kango Model 2500 Accessory tools. Chipping and demolishing capabilities are equivalent to the Model
H 90SC.
3. APPLICATIONS
Demolishing of concrete and similar materials.
Groove and channel digging in concrete.
Groove and channel digging in asphalt and gravel roads.
Tamping/compacting of asphalt and graveled roads.
Cutting of asphalt.
[Typical Applications]
Construction work, piping/wiring work, water supply/drain work, etc.
4. SELLING POINTS
Maker •Model Weight Overall length
HITACHI H 90SE 32 kg (70.5 lbs.) 859 mm (33-13/16")
HITACHI H 90SC 32 kg (70.5 lbs.) 842 mm (33-19/128")
HITACHI H 85 33 kg (72.8 lbs.) 882 mm (34-23/32")
C 29 kg (63.9 lbs.) 818 mm (32-13/64")
B 29 kg (63.9 lbs.) 845 mm (33-17/64")

--- 2 ---
4-1. Selling Point Descriptions
4-1-1. Largest demolition power in this class
The powerful impact force of each blow ensures efficient and easy demolition of concrete.
The demolition performance is 1.0 --- 1.4 times more powerful than that of similar products.
4-1-2. Tool retainer accepts 3 types of 28.5 mm (1-1/8") hex. shank hammer accessories
Three types of hex. shank tools (Fig. 1) can be used
in the Model H 90SE by turning the tool retainer in
the following two methods. Collar type
(Air braker)
Collar and groove type
Groove type
Fig. 1
Maker •Model Ratio of demolished weight (%)
HITACHI H 90SE 100
HITACHI H 90SC 100
HITACHI H 85 85
C70
B85
Highest demolition power in its class
Short overall length design for
more comfortable hammering work
Tool retainer accepts 3 types of
28.5 mm (1-1/8") hex. shank hammer
accessories
Internal double-insulation construction
with sturdy aluminum frame
*: Refer to 8-3. (1) Vibration-Absorbing
Construction for details of Involute
Neidhart.
Improved shock absorbing handle
equipped with Involute Neidhart
spring method * damping

--- 3 ---
Fig. 2
(1) Mounting collar type and shank steel for air brakers and collar & groove type shank steels.
(2) Mounting collar & groove and groove type shank steels.
Fig. 3
4-1-3. Improved shock absorbing handle equipped with Involute Neidhart spring method
The involute-type Neidhart Spring employed in the vibration-absorbing handle significantly reduces operator
fatigue and permits comfortable operation for extended periods of time.
Vibration-absorbing handle Provided Provided Not provided Provided Provided
HITACHI HITACHI HITACHI
H 90SE H 90SC H 85 CB

--- 4 ---
5. SPECIFICATIONS
H 90SE
Power source
Voltage (V)
Motor type
Insulation structure
Enclosure
Switch
Type of handles
Full-load current
Power input
Striking speed
Weight
Packaging
Standard accessories
Single-phase AC 50/60 Hz
110, 115, 230, 240
AC single-phase series commutator motor
Double insulation
Materials: Aluminum alloy die casting
Glass-fiber reinforced plastic resin
Paint: Hammer-net silver green and black
Trigger switch
T-shaped handle
13.9 A (110 V), 13.3A(115 V), 6.6 A (230 V), 6.4 A (240 V)
1,450 W
1,100 /min.
850 /min.
Product: 32.0 kg (70.5 lbs.); excluding cord
Packed: 36.0 kg (79.4 lbs.)
Corrugated cardboard box
Hex. bar wrench (for M12) •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
Hex. bar wrench (for M6) •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
Hex. bar wrench (for M4) •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
Item
No-load
Full-load

--- 5 ---
+
+
+
5-1. Optional Accessories
1. Demolition work
(1) Bull point
2. Grooving and chiseling work
(1) Cold chisel
3. Cutting and stripping work (asphalt cutting, etc.)
(1) Cutter
Width
75 mm (3")
Overall length
520 mm (20-15/32")
Code No.
985232
Overall length
520 mm (20-15/32")
Code No.
985231
Overall length
410 mm (16-9/64")
520 mm (20-15/32")
Code No.
996372
985230

--- 6 ---
6. Grease for impact drill
500 g (1.1 lbs.) can
Code No. 980927
(Note)
Code numbers listed above are subject to change. Please refer to periodic Technical News Bulletins.
4. Digging (substitute pick-ax)
(1) Scoop
Overall length
546 mm (21-1/2")
Code No.
985233
+
5. Tamping work
(1) Rammer (2) Shank
+ +
Code No.
305880
200 mm in dia.
Overall length
395 mm (15-35/64") Code No. 308092

--- 7 ---
6. COMPARISONS WITH SIMILAR PRODUCTS
6-1. Specification Comparisons
Maker
Model name
Power input
Full-load impact rate
Dimensions
(illustration
below)
Striking energy per stroke
Insulation structure
Lubricating method
Vibration-absorbing handle
No-load noise level
Weight (without cord)
HITACHI
A
B
C
W
min-1
mm
mm
mm
J
ft-Ibs.
---
---
---
dB(A)
kg
C
H 90SE
1,450
850
859
(33-13/16")
634
(24-31/32")
728
(28-21/32")
55.0
40.6
Double
insulation
Grease
Provided
88.5
32
(70.5 Ibs.)
H 90SC
1,450
850
842
(33-19/128")
634
(24-31/32")
711
(28")
55.0
40.6
Double
insulation
Grease
Provided
88.5
32
(70.5 Ibs.)
H 85
1,330
950
882
(34-23/32")
642
(25-9/32")
51.0
37.6
Single
insulation
Oil
Not provided
86.0
33
(72.8 Ibs.)
---
1,700
1,000
818
(33-13/64")
588
(23-5/32")
55.3
40.8
Double
insulation
Grease
Provided
99.0
29
(63.9 Ibs.)
---
B
1,800
1,030
845
(33-17/64")
594
(23-3/8")
50.0
36.9
Double
insulation
Grease
Provided
95.6
29
(63.9 Ibs.)
700
(27-9/16")
A
C
B

--- 8 ---
6-2. Demolition Performance Comparisons
The data shown in Fig. 4 are obtained in actual factory tests, and are for reference only. The demolished amount
may vary in accordance with operating conditions, operator skill, etc.
Fig. 4
Demolished weight for 30 min. (kg)
At rated
voltage
200 250 300 350 400 Demolished amount
(kg/30 min.)
349 (768 lbs.)
349 (768 lbs.)
297 (653 lbs.)
244 (537 lbs.)
297 (653 lbs.)B
C
H 85
H 90SC
H 90SE

--- 9 ---
7. PRECAUTIONS IN SALES PROMOTION
In the interest of promoting the safest and most efficient use of the Model H 90SE Electric Hammer by all of our
customers, it is very important that, at the time of sale, the salesperson carefully ensures that the buyer seriously
recognizes the importance of the contents of the Handling Instructions, and fully understands the meaning of the
precautions listed on the Caution Plate attached to each tool.
7-1. Handling Instructions
Although every effort is made in each step of design, manufacture and inspection to provide protection against
safety hazards, the dangers inherent in the use of any electric tool cannot be completely eliminated. Accordingly,
general precautions and suggestions for the use of electric power tools, and specific precautions and suggestions
for the use of the Electric Hammer are listed in the Handling Instructions to enhance the safe, efficient use of the
tool by the customer. Salespersons must be thoroughly familiar with the contents of the Handling Instructions to
be able to offer appropriate guidance to the customer during sales promotion.
7-2. Caution Plate
The Model H 90SE unit is provided with a Caution Plate (illustrated below) which lists basic safety precautions in
its use. Carefully ensure that the customer fully understands and follows these precautions before using the tool.
For the U.S.A. and Canada
For Australia
CAUTION
Read thoroughly HANDLING INSTRUCTIONS before use.
-- WARNING -- To reduce the
risk of injury,
user must read and understand instruction manual.
AVERTISSEMENT Afin de rèduire le risque de
blessures, l'utilisateur doit lire et
bien comprendre le mode d'emploi.
Hitachi Koki

--- 10 ---
To ensure the smooth reciprocating of the striker and the second hammer, special grease (Part No. 980927
for impact drill) is used in the hammering section. If the hammering section [inside the cylinder case and
housing (crank shaft side)] is disassembled, thoroughly wipe away all old grease from all parts, and apply
70 g (2.3 oz) of new grease within the cylinder case and 50 g (1.7 oz) of new grease within the housing
(crank shaft side). Do not exceed the designated amounts of grease. If there is excessive grease, it may
flow between the striker and piston and cause reduced hammering efficiency and/or increased recoil force.
7-3. Grease Replacement
Different kinds of grease are used in the electro-pneumatic hammering section and the speed-change gear
section. It is not necessary to replenish the grease between 6-month (approx.) change intervals unless the tool is
disassembled or there is grease leakage due to a damage or worn seal.
N.P.C. SEP-3A (Part No. 930035) is used in the speed-change gear section (inside the gear cover). The proper
supply amount is 100 g (3.3 oz). Never use the hammering section special grease in the speed-change section.
The special soft grease would leak into the motor section and cause serious problems.
7-4. O-Ring Replacement
The O-ring mounted on the piston is extremely important to ensure adequate sealing of the air pressure. Although
the O-ring is made of special rubber to ensure a long service life, it does nonetheless become worn and should be
replaced periodically depending on the frequency of tool use. With average use, it is recommended that the
O-ring should be replaced every six months to ensure maximum effectiveness.

--- 11 ---
8. REFERENCE INFORMATION
8-1. Air Damper
There is an air chamber constructed between the second hammer and the hammer holder. The compression of
the air within the air chamber functions in the same way as a spring to maintain continuous and close contact
between the second hammer and the accessory tool mounted in the retainer. Because of this continuous close
contact between the second hammer and the accessory tool, digging and cutting work in asphalt, gravel and other
such comparatively soft materials can be accomplished with ease and efficiency.
Fig. 5
8-2. Sealed and Dustproof Construction
The cylinder case section and the housing (crank shaft side) are sealed by six (6) O-rings, and the bearing portion
of the crank shaft is sealed by an oil seal. These seals serve to prevent leakage of the grease, as well as to
prevent dust and dirt from entering the mechanism.
Accessory tool
O-ring O-ring (A) Piston
Striker
Second hammer
Hammer holder
Air chamber
Fig. 6
Switch handle
Oil seal
O-ring
(33.5 mm inner dia.)
O-ring
(79.5 mm inner dia.)
Housing
O-ring (A)
(36 mm inner dia.)
O-ring
(89.5 mm inner dia.)
O-ring (D)
(77.4 mm inner dia.)
Cylinder case Crank shaft
O-ring
(111.5 mm inner dia.)
Bearing portion of crank shaft

--- 12 ---
8-3. Vibration-Absorbing Construction
(1) Vibration-absorbing construction
A hole passing through the housing ass'y houses a handle shaft which in turn supports a switch handle and
side handle which are mounted in a T shape, at right angles to the operating direction of the main body of
the tool. The handle shaft can be turned and is installed in a position slightly deviated from the handle
operating point. Both ends of the handle shaft are equipped with Neidhart Springs, each of which consists
of four rubber handle dampers inserted between a handle holder (B) and a handle holder (A). Each handle
holder (A) has four involute-type, wing-shaped appendages. When the operator pushes down on the
handles, each holder (A) rotates, bending the handle dampers and reducing vibration. Also, the angle of
rotation of the handles is controlled by stoppers. Through adoption of this type of vibration-absorbing handle
construction, the Model H 90SE causes much less operator fatigue and can be comfortably operated for
significantly longer periods than conventional products.
SW lever Housing Handle shaft
Holder (B)
Side handle
Stopper
Handle
holder (A)
Holder (A)
Holder (B)
Handle shaft
Involute Neidhart Spring
Holder (A)
Handle holder (A)
Hole
Handle
holder (B)
Handle (A)
(B)
Handle damper (4 pcs.)
Fig. 7
Fig. 8
Handle damper (4 pcs.)
Holder (A)
Holder (B)
Handle shaft Stopper
Hole Holder (B)
Holder (A)
Handle damper (4 pcs.)
Side handle
Handle holder (A)
Housing
Stopper
Handle holder (B)
SW lever
Handle (B)
Handle (A)

--- 13 ---
(2) Level of handle vibration in 'Z' direction
The graph below illustrates the relationship between handle pressing force and handle vibration level in the
'Z' direction.
130
125
120
115
110
0 5 10 15 20
Pressing force (load) (kgf)
Vibration level (dB)
Vibration level of main body in Z direction
Vibration level of handles in Z direction
Z
Z
Z
(Note) For improved operability in chipping and breaking operations, it is recommended that operating force be
limited to the dead weight of the tool rather than pressing forcefully down on the handles. In keeping
with this, the handle pressing force at which the vibration-absorbing effect is maximum is set for
between 5 and 10 kg. The customer should be cautioned to avoid pressing fully down on the handles
during operation.

--- 14 ---
8-4. Tool Retainer
Three types of shank tools (Fig. 1) can be mounted to
the Model H 90SE by turning the saddle-shaped
retainer.
(1) Mounting air tool shank tool and standard hex.
shank tool
Raise the retainer in A direction and insert the
tool shank into the hexagonal hole of the front
cover as far as it will go (Fig. 9). Put the retainer
back in position to fix the tool shank (Fig. 10).
(2) Mounting standard hex. shank tool and retaining
groove tool without collar
Lower the retainer in B direction and insert the
tool shank into the hexagonal hole of the front
cover as far as it will go facing the recessed
portion of the tool shank to the retainer (Fig. 11).
Turn the retainer in C direction to fix the tool
shank (Fig. 12).
Fig. 9
Tool shank
Front cover
Retainer
Fig. 10
Fig. 11 Fig. 12
Tool shank Front cover
Recessed portion
Retainer
BC
A

--- 15 ---
9. REPAIR GUIDE
9-1. Precautions and Suggestions for Disassembly and Reassembly of the Main Body
The [Bold] numbers in the descriptions below correspond to the item numbers in the Parts List and exploded
assembly diagram.
9-1-1. Disassembly
[NOTE] If it is difficult to loosen and remove the fixing bolts, use an appropriate heating device to heat them to
approximately 80 ˚C (176 ˚F).
Disassembly of the Armature Ass'y [99]
(1) Remove the two Seal Lock Hex. Socket Hd. Bolts M4 x 10 [89], and disassemble the Cap Cover [90] and the
Carbon Brushes [92].
(2) Loosen the Lock Nut M8 (Nylon Insert) [48], and remove the Washer M8 [47]. Then, while pressing on the
Switch Handle side, pull the Side Handle [55] and Handle Holder (A) [56] from the Handle Shaft [51]. Next,
pull off the Switch Handle side and gently tap the end of the Handle Shaft [51] on one side to loosen and
remove the Holder (A) [53] and Handle Dampers [54] (4 pcs.) from one side. The Handle Shaft [51] can then
be extracted from the Housing Ass'y [85].
(3) Remove the four Seal Lock Hex. Socket Hd. Bolts M10 x 60 [58] and two Seal Lock Hex. Socket Hd. Bolts
M10 x 55 [66] and take off the Gear Cover Ass'y [59]. At the same time, also remove the First Gear [68] and
Second Gear [69]. Next, by inserting a flat-blade screwdriver or similar tool into one of the air vents of the
Inner Cover [76] and lifting it upwards, the Inner Cover [76], Armature Ass'y [99], Crank Shaft [84], and
connected parts can be removed in a single body.
(4) As illustrated in Fig. 13, support the Inner Cover [76] with an appropriate tubular jig (100 mm inner dia.), and
push down on the pinion end of the Armature Ass'y [99] with an arbor press to separate the Armature Ass'y
from the Inner Cover [76]. At this time, be very careful not to lose the Bearing Washer [74] which is mounted
on the fan ass'y portion of the Armature Ass'y.
Fig. 13
Bearing Washer [74]
Push
Armature Ass'y [99]
Tubular Jig
Crank Shaft [84]
Inner Cover [76]
100 mm

--- 16 ---
Disassembly of the Crank Shaft [84] section
Remove the four Seal Lock Hex. Socket Hd. Bolts M8 x 18 [81]. As illustrated in Fig. 14, support the lower
surface of the Inner Cover [76] with an appropriate tubular jig (100 mm inner dia.), apply an appropriate steel
rod (maximum diameter of 19 mm) to the end surface of the Crank Shaft [84], and push it downward with an
arbor press. The Ball Bearing 6204VVCM [62], Distance Ring (A) [63], Distance Ring (B) [65], Distance Ring
(C) [77], Final Gear [64], Feather Keys 4 x 4 x 10 [70], Bearing Boss [80], Ball Bearing 6305VVCM [78] and
Crank Shaft [84] can then be removed from the Inner Cover [76].
Then, remove the three Seal Lock Hex. Socket Hd. Bolts M5 x 12 [71], and take off Bearing Cover (A) [72]
and the Ball Bearing 6203DDCM [73].
Final Gear [64]
Push
Tubular jig
Distance Ring (A) [63]
Inner Cover [76]
Crank Shaft [84]
Disassembly of the Front Cover [7] section
Secure the Cylinder Case [15] in a vise, and heat the Cylinder Case mounting portion of the Front Cover [7] to
a temperature of approx. 80 ˚C (176 ˚F) with an appropriate heating device. Then, remove the six Nylock High
Tension Bolts M12 x 40 [4]. The Front Cover [7] together with the Second Hammer [10] and the Hammer
Holder [13] can then be removed from the Cylinder Case [15] in a single body. The Damper [14] can then be
taken out.
Removal of O-Ring (A) [12]
As O-Ring (A) [12] is installed in the inner portion of the Hammer Holder [13], it may be difficult to remove. As
illustrated in Fig. 15, pry O-Ring (A) upward gently with a small flat-blade screwdriver, being very careful not to
damage the surface of the O-Ring.
Fig. 14
Fig. 15
Flat-blade screwdriver
Hammer Holder [13]
O-Ring (A) [12]

--- 17 ---
Removal of the Striker [19] and related parts
Remove the four Nylock Bolts M10 x 45 [16], and separate the Cylinder Case [15] from the Housing Ass'y
[85]. From the Cylinder Case, take out the Striker [19], Piston [20] and Connecting Rod Ass'y [23] in a single
body. Next, remove the O-Ring (P-46) [22] from the back of the Piston, and pull out the Piston Pin [21]. The
Piston [20] can then be separated from the Connecting Rod Ass'y [23]. Finally, tap gently on the end of the
Piston to remove the Striker [19].
Disassembly of the Switch [43] and related parts
Pry off the Retaining Ring (E-Type) [27] with a small flat-blade screwdriver, pull out the Pin [25], and remove
the Switch Lever [26]. Then, remove the two Seal Lock Hex. Socket Hd. Bolts M6 x 30 [28] on the Handle (B)
side and the two Tapping Screws D4 x 20 [50], and remove Handle (B) [49].
Disassembly of the Retainer [1] section
Remove the two Roll Pins D6 x 55 [2] from the 6 mm dia. holes of the Retainer [1] and remove the Lever Pin
[3]. The Retainer [1] and two Retainer Dampers [6] and two Damper (B) [5] can then be removed from the
Front Cover [7] (Fig. 16).
Roll Pin D6 x 55 [2] (2 pcs.)
Fig. 16
Front Cover [7]
Lever Pin [3]
Retainer Damper [6]
(2 pcs.)
Retainer [1]
Damper (B) (2 pcs.) [5]

--- 18 ---
9-1-2. Reassembly
Reassembly can be accomplished by following the disassembly procedure in reverse. However, special attention
should be given to the following items.
Reassembly of the Crank Shaft [84] section
Mount the Bearing Boss [80], Oil Seal [82] and Ball Bearing 6305VVCM [78], and Distance Ring (C) [77] onto
the Crank Shaft [84], and secure the Bearing Boss [80] to the Inner Cover [76] with the four Seal Lock Hex.
Socket Hd. Bolts M8 x 18 [81]. Support the inner race of the Ball Bearing 6305VVCM [78] with a J-127-5
Sleeve (Special Repair Tool, Part No. 970899), and press fit the Crank Shaft [84] into the Ball Bearing
6305VVCM [78]. Then, insert Distance Ring (B) [65] and the two Feather Keys 4 x 4 x 12 [83] onto the Crank
Shaft [84] and press fit the Final Gear [64].
Finally, press fit the Ball Bearing 6204VVCM [62] and Distance Ring (A) [63] onto the Crank Shaft [84].
Reassembly of the Armature Ass'y [99]
Press fit the Ball Bearing 6203DDCM [73] into the Inner Cover [76], cover it with Bearing Cover (A) [72], and
secure the assembly with the three Seal Lock Hex. Socket Hd. Bolts M5 x 12 [71].
Reassembly of the Striker [19]
Push the Striker [19] into the inside of the Piston [20] until a 'hissing' sound is heard. When the hissing sound
is heard, the Striker is properly inserted in the Piston. (The hissing is the sound of the compressed air
escaping from the Piston when the Striker reaches the respiratory chambers within the Piston.) In this state,
align the piston pin inserting holes of the Piston [20] and Connecting Rod Ass'y [23], and insert the Piston Pin
[21]. Finally, mount the O-Ring (P-46) [22] in the groove at the rear portion of the Piston [20].
Piston [20]
Fig. 17
Striker [19] O-Ring [22] Connecting Rod Ass'y [23]
Piston Pin [21]
Respiratory chambers