Hitachi DH 24PG Assembly instructions

LIST Nos.

DH 24PG: F420

DH 26PB: F417

DH 28PBY: F414

May 2013

PRODUCT NAME

Hitachi Rotary Hammer

Models DH 24PG

DH 26PB

DH 28PBY

Sales Division

REPAIR GUIDE



---------------------------------------------------------------------------------------------------------------- 1

1. Precautions on disassembly and reassembly ----------------------------------------------------------- 1

STANDARD REPAIR TIME (UNIT) SCHEDULES ------------------------------------------------------------------ 19

CONTENTS Page

-1-

Be sure to disconnect the power cord plug from the power supply before conducting repair. Otherwise, the

motor may suddenly turn on, posing a very dangerous situation.

1. Precautions on disassembly and reassembly

(Bold) numbers in the descriptions below correspond to item numbers in the Parts List and exploded

assembly diagram for the Model DH 24PG, <Bold> numbers to those for the Model DH 26PB, and {Bold}

numbers to those for the Model DH 28PBY. [Bold] numbers correspond to item numbers for the Models

DH 24PG, DH 26PB, and DH 28PBY.

1. Disassembling the tool retainer ass’y

Fully pull the Grip [3] in the arrow direction and detach the Front Cap [1].

Then use the retaining ring puller to remove the Stopper Ring [2], while pulling the Grip [3] in the arrow

direction. You can now detach the Grip [3], Ball Holder [4], Steel Ball D7.0 [19], Holder Plate [5], and

Holder Spring [6] from the Cylinder [20].

Disassembly

REPAIR GUIDE

Fig. 1 ƔDisassembling the tool retainer ass’y

Grip [3]

Front Cap [1] Holder Plate [5]

Ball Holder [4]

Stopper Ring [2]

Cylinder [20]

Steel Ball D7.0 [19]

Grip [3]

Holder Spring [6]

-2-

Fig. 2 ƔRemoval of the change lever

Change Lever (13)<12>{12} Pushing Button [11] pin route

2. Removing the change lever

Push in the Pushing Button [11] at the "Rotation + Hammering" ( mark) position, turn the Change

Lever (13)<12>{12} counterclockwise a little, and then fully push in the Pushing Button [11]. In this state,

turn the Change Lever (13)<12>{12} clockwise. When the lever stops, release the Pushing Button [11]

and then turn the Change Lever (13)<12>{12} clockwise. When the lever stops again, push in the Pushing

Button [11] and then turn the Change Lever (13)<12>{12} clockwise once more. At this position, ply up

the Change Lever (13)<12>{12} in order to remove it.

-3-

Fig. 3 ƔDisassembling the hammering mechanism

Hand press

Rear end of the Second Shaft [41]

Clutch [44] end face

Clutch

[

]

end face

3. Disassembling the hammering mechanism

Use a drill bit or screwdriver to push in the Second Hammer [30], and then remove the Striker [36] that is

chucked by O-ring (C)[33]. Remove the Tapping Screw (W/Flange) D5 x 35 (66)<66>{76} from the

Housing (65)<65>{75} and then detach the Gear Cover [7]. Do not let the Inner Cover [53] come off from

the Housing (65)<65>{75}. Otherwise, the Armature (59)<59>{65} will come off together with the Inner

Cover [53], thereby damaging its carbon brushes and the commutator.

Remove the Seal Lock Hex. Socket Hd. Bolt M5 x 16 [48] from the Bearing Holder [49], rotate the Second

Shaft [41] to allow the Piston [38] to reach the top dead point (towards the Inner Cover [53]). The

Reciprocating Bearing [47] arm comes off from the Piston Pin [39] and parts on the Second Shaft [41]

come off together from the Inner Cover [53]. The Seal Lock Hex. Socket Hd. Bolt M5 x 16 [48] loses its

bonding force when disassembled. Accordingly, it must be replaced by a new one when reassembled.

Hold the end face of the Clutch [44] as shown below, use a hand press to push the rear end of the

Second Shaft [41] in order to push out the First Gear [51], Bearing Cover [50], Ball Bearing

608VVC2PS2L [17], Bearing Holder [49], Bearing Washer [18], Reciprocating Bearing [47], Clutch [44],

Change Plate [46], Washer [45], Clutch Spring [43], and Washer (C) [42] from the Second Shaft [41].

Note that the First Gear [51] is press-fitted to the rear end of the Second Shaft [41] for alignment.

-4-

4. Disassembling the cylinder ass’y

(1) Disassembly of the slip clutch ass’y

Remove the tool retainer ass’y and pull out the Cylinder [20] ass’y from the Gear Cover [7]. Remove

Washer (A) [25] from the Cylinder [20] and then use the retaining ring puller to pull out the Retaining Ring

for D30 Shaft [26]. Washer (A) [25], Spring (A) [24], the Second Gear [23], Cylinder Clutch [22], and Pin

D2.5 [21] can now be removed from the Cylinder [20].

(2) Disassembly of the cylinder inside

Insert stopper ring jig (A) (J-341) into the Cylinder [20] from the non-hole side as shown in Fig. 4 until it

contacts the end of the Damper Holder [34]. Clamp the ends of the Cylinder [20] and stopper ring jig (A)

(J-341) with a vise to compress Damper (A) [32]. (Push the Stopper Ring [35] with punch (C) (J-341) and

make sure it moves a little.) In this state, insert punch (C) (J-341) into each of the two ĭ8 holes on the

Cylinder [20]. Hammer the punch head to give force to the periphery of the Stopper Ring [35] in order to

detach the ring from the bore groove of the Cylinder [20]. Fully hammer along the periphery of the Stopper

Ring [35] until the Stopper Ring [35] disappears from the two ĭ8 holes.

Then unclamp the Cylinder [20] from the vise and use ring puller jig (B) (J-341) to pull out the Stopper

Ring [35] from the inner circumference of the Cylinder [20]. Be careful not to let the Stopper Ring [35] pop

out. Once the Stopper Ring [35] is detached from the Cylinder [20], Hammer Holder (C) [28], Sleeve (FW)

[29], the Second Hammer [30], Hammer Holder (A) [31], Damper (A) [32], O-ring (C) [33], and the

Damper Holder [34] can be removed from the Cylinder [20]. Here the Stopper Ring [35] is deformed by

disassembly and must be replaced by a new one when reassembled. Replace O-ring (C) [33] with a new

one at each disassembly to prevent dry firing.

Fig. 4 ƔDisassembling the cylinder ass’y

Hammer the punch head.

Punch

(

)

(

J-341

)

ĭ8 hole (2 holes)

Vise

Damper (A) [32]

Sleeve (FW) [29]

Hammer Holder (A) [31]

Hammer Holder (C) [28]

Stopper ring jig (A) (J-341)

Second Hammer [30] O-ring (C) [33]

Damper Holder [34]

Stopper Ring [35]

-5-

Reassembly can generally be conducted by reversing the disassembly procedure. However, special

attention should be given to the following items.

1. Reassembling the cylinder ass’y

Insert the set of Hammer Holder (C) [28], Sleeve (FW) [29], the Second Hammer [30], Hammer Holder

(A) [31], Damper (A) [32], O-ring (C) [33], and the Damper Holder [34] into the Cylinder [20] to which Oil

Seal (A) [27] is press-fitted. (Do not reverse the seal orientation.) (Assemble with the bore slope of

Hammer Holder (C) [28] set at the rear end and with the Sleeve (FW) [29] notch set at the front end as

shown in Fig. 5. Do not reverse the assembly order.) Push a new Stopper Ring [35] into the Cylinder [20]

with the break of the Stopper Ring [35] facing away from the ĭ8 hole on the Cylinder [20] as shown in Fig.

5. With the ring break facing toward the ĭ8 hole, the cylinder assembly is difficult to disassemble. Note the

ĭ8 hole on the Cylinder [20] and correctly orient the Stopper Ring [35] as shown in Fig. 5 when pushing in.

Insert stopper ring jig (A) (J-341) from the hole side and use a hand press to press against the upper end

of the jig until the Stopper Ring [35] is fitted into the bore groove of the Cylinder [20]. Confirm that the

Stopper Ring [35] is fit securely into the bore groove of the Cylinder [20] through the two ĭ8 holes on the

periphery of the Cylinder [20].

Reassembly

Fig. 5 ƔInside structure of the cylinder ass’y

Hand press

Second Hammer [30]

Hammer Holder (C) [28]

Hammer Holder (A) [31]

Damper (A) [32]

Sleeve (FW) [29]

ĭ8 hole (2 holes)

Damper Holder [34]

O-ring (C) [33]

Stopper ring jig (A) (J-341)

Stopper Ring [35]

Oil Seal (A) [27]

Sleeve (FW) [29] notch

Cylinder [20]

ĭ8 hole

Stopper Ring [35] break

Bore slope of Hammer Holder (C) [28]

-6-

2. Press-fitting the first gear

Match the end of the First Gear [51] with the rear end of the Second Shaft [41] and then press-fit. After

press-fitting the First Gear [51], confirm that the inner ring of the Reciprocating Bearing [47] shaft rotates

smoothly.

3. Mounting the oil seals

In reassembly of the Oil Seal [9] and Oil Seal (A) [27], apply grease to the inner circumferences of both

seals, but do not apply grease along their peripheries. Be careful not to skew the Oil Seal [9] and Oil Seal

(A) [27] when press-fitting these parts.

4. Reassembling the internal pressure adjusting mechanism

Insert Felt Packing (A) (64)<64>{71} into the hole on the Air Cap (63)<63>{70} and lay the Air Cap

(63)<63>{70} over the ĭ8.4 shaft of the Inner Cover [53]. Fit the inside boss of the Air Cap (63)<63>{70}

hole to the groove on the ĭ8.4 shaft of the Inner Cover [53].

Fig. 6 ƔReassembling the internal pressure adjusting mechanism

Air Cap (63)<63>{70}

Felt Packing (A) (64)<64>{71}

Fit the boss to the groove.

Inner Cover [53]

A – A (2:1)

-7-

5. Reassembling the low vibrations mechanism (DH 28PBY)

Degrease Weight Damper (A) <54> bonding area of the Inner Cover <53> and then bond Weight Damper

(A) <54> to the area. Degrease the threaded portion of Weight (A) <55>, mount Weight (B) <57> and the

Leaf Spring <56> on Weight (A) <55>, and then secure both parts with the Seal Lock Hex. Socket Hd. Bolt

M3 x 8 <58>. Degrease the threaded portion of the Inner Cover <53>. Insert the Spring Damper <72> into

the Inner Cover <53> and Spring Holder <73>, and then secure the Leaf Spring <56> and Spring Holder

<73> with the Seal Lock Hex. Socket Hd. Bolt M4 x 12 <74>. Place Weight (A) <55> on the Inner Cover

<53> side and Weight (B) <57> on the Housing <75> side. Do not reverse the positions.

Degrease Weight Damper (B) <66> bonding area of the Fan Guide <67> and bond Weight Damper (B)

<66> to the area. Mount the Cover Plate <64> before inserting the Armature <65> into the Inner Cover

<53>. Mount the Cover Plate <64> with its body projected toward the Inner Cover <53> as shown in Fig. 7.

Fit the projection of the Inner Cover <53> into the hole on the Cover Plate <64>.

Fig. 7 ƔReassembling the low vibrations mechanism

Inner Cover <53>

Weight Damper (A) <54> bonding area

Weight Damper (B) <66> bonding area

Spring Damper <72>

Thread

Weight Damper (B) <66>

Fan Guide <67>

Seal Lock Hex. Socket

Hd. Bolt M4 x 12 <74>

rin

Holder <73>

Cover Plate <64>

Weight (A) <55> Wei

(

)

<57>

Thread

Leaf Spring <56>

Seal Lock Hex. Socket

Hd. Bolt M3 x 8 <58>

-8-

Fig. 8 ƔMounting the piston

Inner Cover [53] ass’y

Breathing groove of Piston [38]

Piston [38]

Striker [36]

O-ring D17 [37]

Air chamber

6. Mounting the piston

Mount the Piston [38] as shown in Fig. 8.

Apply the specified grease to the inner and outer circumferences of the Piston [38]. Also apply grease to

the inner and outer circumferences of the Piston Pin [39] and Piston Washer [40]. Mount the Piston

Washer [40] on the Piston [38] and then insert the Piston Pin [39].

Fill 20 grams of the specified grease into the cylinder of the Inner Cover [53] and then insert the Piston

[38] into the cylinder of the Inner Cover [53]. Insert the arm of the Reciprocating Bearing [47] of the

Second Shaft [41] assembly into the Piston Pin [39] so that the arm of the Reciprocating Bearing [47] is

sandwiched between the two Piston Washers [40] as shown in Fig. 9.

After inserting the arm, insert the spigot joint of the Bearing Holder [49] into the Inner Cover [53] with the

threaded portions of the Inner Cover [53] aligned with the holes of the Bearing Cover [50] and Bearing

Holder [49]. Here, orient the Bearing Holder [49] as shown in Fig. 10.

As shown in Fig. 11, one of the bolts touches the Reciprocating Bearing [47] and cannot be inserted

straight into the Inner Cover [53]. Therefore, tighten one bolt at a time, rotate the Reciprocating Bearing

[47] so that new Seal Lock Hex. Socket Hd. Bolt M5 x 16 [48] can be inserted straight in, and then fully

tighten the bolts.

After tightening the bolts, allow the Reciprocating Bearing [47] to make one rotation and confirm that the

Piston [38] makes one reciprocation. Pull the Piston [38] to confirm that it does not come off.

Pushing the Striker [36] into the Piston [38] compresses the air in the air chamber. The compressed air is

released when O-ring D17 [37] exceeds the breathing channel of the Piston [38]. Push in the Striker [36]

until O-ring D17 [37] exceeds the breathing channel of the Piston [38]. (Listen for the sound of air being

released when O-ring D17 [37] exceeds the breathing channel of the Piston [38].)

-9-

Fig. 9 ƔMounting the piston Fig. 10 ƔMounting the bearing holder

Fig. 11 ƔTightening the bolts

Piston Washer [40]

Piston [38]

Arm of Reciprocating Bearing [47]

Bearing Cover [50]

Inner Cover [53]

Bearing Holder [49]

Seal Lock Hex. Socket Hd.

Bolt M5 x 16 [48]

CAUTION: Do not tighten the bolt when

it is skewed in contact with

the reciprocating bearing.

Flat portion of Bearing Holder [49]

Inner Cover [53]

Other manuals for DH 24PG

This manual suits for next models

Table of contents

Other Hitachi Rotary Hammer manuals

Hitachi

Hitachi DH 24PD3 User manual

Hitachi

Hitachi DH 24PC Instruction Manual

Hitachi

Hitachi DH24PB3 Manual

Hitachi

Hitachi DH24PB3 Operator's manual

Hitachi

Hitachi DH 40MRY Manual

Hitachi

Hitachi DH 50MRY User manual

Hitachi

Hitachi DH 50MRY User manual

Hitachi

Hitachi DH 45MR User manual

Hitachi

Hitachi DH 22PB Instruction Manual

Hitachi

Hitachi DH 50MRY User manual

Hitachi

Hitachi DH 28PC User manual

Hitachi

Hitachi DH 45SA User manual

Hitachi

Hitachi DH50SBK - 2" Spline Rotary HAMMERW/CASE 10.4Amp... User manual

Hitachi

Hitachi cordless hammer Instruction Manual

Hitachi

Hitachi DH24PB3 User manual

Hitachi

Hitachi DH 36DPA User manual

Hitachi

Hitachi DH 40FA Instruction Manual

Hitachi

Hitachi DH 40MRY Manual

Hitachi

Hitachi DH 45MEY User manual

Hitachi

Hitachi DH 28PC User manual

Hitachi

Hitachi DH 18DPA User manual

Hitachi

Hitachi DH 25PA User manual

Hitachi

Hitachi DH 40MA User manual

Hitachi

Hitachi DH 36DBL User manual

Popular Rotary Hammer manuals by other brands

Bosch

Bosch GSH 5 CE Original instructions

Toya

Toya VOREL 81133 manual

Makita

Makita HR2470 instruction manual

Hilti

Hilti TE 2-A22 manual

Makita

Makita HR3851 Parts Breakdown

Makita

Makita RH01 instruction manual

EINHELL

EINHELL HEROCCO Original operating instructions

YATO

YATO YT-82772 Original instructions

Hilti

Hilti TE15-C operating instructions

BorMann

BorMann BPH7000 Translation of the original instructions

Makita

Makita DHR280 instruction manual

Metabo HPT

Metabo HPT DH 3628DD Safety instructions and instruction manual

Black & Decker

Black & Decker KD650 manual

Bosch

Bosch GBH Professional 2-20 DRE Original instructions

Makita

Makita HR2010 instruction manual

Makita

Makita HR2450X8 instruction manual

Makita

Makita HR2020 instruction manual

Bosch

Bosch 2-26 E operating instructions