service manual instant download

1. SERVICE MANUAL
KOBELCO CONSTRUCTION MACHINERY AMERICA, LLC.
245 E NORTH AVENUE
CAROL STREAM, IL 60188 U.S.A.
English
Part Number S5YT0010E01
Printed in U.S.A. • Rac
S5YT0010E01
Issued November 2010
APPLICABLE:
70SR-2 Acera . . . . . . . . . . . . . YT06-18001 and higher
Hydraulic Excavator
70SR-2 Acera

2. SERVICE
MANUAL model
INDEX
HYDRAULIC EXCAVATOR
SPECIFICATIONS
MAINTENANCE
SYSTEM
DISASSEMBLING
TROUBLESHOOTING
E
/
G
OPT.
1
2
3
4
5
6
7
SPECIFICATIONS SECTION
MAINTENANCE SECTION
SYSTEM SECTION
DISASSEMBLY SECTION
TROUBLESHOOTING
ENGINE SECTION
PROCEDURE OF INSTALLING
OPTIONS SECTION
Book Code No.S5YT0010E01
0-1
70SR-2 ACERA

3. 0-2
GENERAL SAFETY INFORMATION
Do not operate or perform any maintenance on this
machine until all instructions found in the OPERA-
TOR’S MANUAL and this MANUAL have been thor-
oughly read and understood.
Improper operation or maintenance of this machine
may cause accidents and could result in serious in-
jury or death.
Always keep the manual in storage.
If it is missing or damaged, place an order with an
authorized our Distributor for a replacement.
If you have any questions, please consult an autho-
rized our Distributor.
(1) Most accidents, which occur during operation, are
due to neglect of precautionary measures and safe-
ty rules. Sufficient care should be taken to avoid
these accidents. Erroneous operation, lubrication
or maintenance services are very dangerous and
may cause injury or death of personnel. Therefore
all precautionary measures, NOTES, DANGERS,
WARNINGS and CAUTIONS contained in the man-
ual and on the machine should be read and under-
stood by all personnel before starting any work with
or on the machine.
(2) Operation, inspection, and maintenance should be
carefully carried out, and safety must be given the
first priority. Messages of safety are indicated with
marks. The safety information contained in the
manual is intended only to supplement safety
codes, insurance requirements, local laws, rules
and regulations.
(3) Messages of safety appear in the manual and on
the machine : All messages of safety are identified
by either word of "DANGER", "WARNING" and
"CAUTION".
1) DANGER- Indicates an imminently hazardous
situation which, if not avoided, will result in
death or serious injury and is represented as
follows:
2) WARNING- Indicates a potentially hazardous
situation which, if not avoided, could result in
death or serious injury and is represented as
follows:
3) CAUTION- Indicates a potentially hazardous
situation which, if not avoided, may result in mi-
nor or moderate injury. It may also be used to
alert against possible damage to the machine
and its components and is represented as fol-
lows:
(4) It is very difficult to forecast every danger that may
occur during operation. However, safety can be en-
sured by fully understanding proper operating pro-
cedures for this machine according to methods
recommended by Manufacturer.
(5) While operating the machine, be sure to perform
work with great care, so as not to damage the ma-
chine, or allow accidents to occur.
(6) Continue studying the manual until all Safety, Oper-
ation and Maintenance procedures are completely
understood by all persons working with the ma-
chine.

4. 0-3
SAFETY PRECAUTIONS
The proper and safe lubrication and maintenance
for this machine, recommended by Manufacturer,
are outlined in the OPERATOR’S MANUAL for the
machine.
Improper performance of lubrication or mainte-
nance procedures are dangerous and could result
in injury or death. Read and understand the MAN-
UAL before performing any lubrication or mainte-
nance.
The serviceman or mechanic may be unfamiliar with
many of the systems on this machine. This makes it
important to use caution when performing service work.
A knowledge of the system and or components is im-
portant before the removal or disassembly of any com-
ponent.
Because of the size of some of the machine compo-
nents, the serviceman or mechanic should check the
weights noted in this manual. Use proper lifting proce-
dures when removing any components. Weight of com-
ponents table is shown in the section ;
SPECIFICATIONS.
The following is a list of basic precautions that must al-
ways be observed.
(1) Read and understand all Warning plates and decal
on the machine before Operating, Maintaining or
Repairing this machine.
(2) Always wear protective glasses and protective
shoes when working around machines. In particu-
lar, wear protective glasses when using hammers,
punches or drifts on any part of the machine or at-
tachments. Use welders gloves, hood/goggles,
apron and the protective clothing appropriate to the
welding job being performed. Do not wear loose fit-
ting or torn clothing. Remove all rings from fingers,
loose jewelry, confine long hair and loose clothing
before working on this machinery.
(3) Disconnect the battery and hang a "Do Not Oper-
ate" tag in the Operator’s Compartment. Remove
ignition keys.
(4) If possible, make all repairs with the machine
parked on a firm, level surface. Block the machine
so it does not roll while working on or under it. Hang
a "Do Not Operate" tag in the Operators Compart-
ment.
(5) Do not work on any machine that is supported only
by lift, jacks or a hoist. Always use blocks or jack
stands, capable of supporting the machine, before
performing any disassembly.
Do not operate this machine unless you have
read and understand the instructions in the OP-
ERATOR’S MANUAL. Improper machine opera-
tion is dangerous and could result in injury or
death.
(6) Relieve all pressure in air, oil or water systems be-
fore any lines, fittings or related items are discon-
nected or removed. Always make sure all raised
components are blocked correctly and be alert for
possible pressure when disconnecting any device
from a system that utilizes pressure.
(7) Lower the bucket, dozer, or other attachments to
the ground before performing any work on the ma-
chine. If this cannot be done, make sure the bucket,
dozer, ripper or other attachment is blocked correct-
ly to prevent it from dropping unexpectedly.
(8) Use steps and grab handles when mounting or dis-
mounting a machine. Clean any mud or debris from
steps, walkways or work platforms before using.
Always face to the machine when using steps, lad-
ders and walkways. When it is not possible to use
the designed access system, provide ladders, scaf-
folds, or work platforms to perform safe repair oper-
ations.
(9) To avoid back injury, use a hoist when lifting com-
ponents which weigh 20kg (45lbs) or more. Make
sure all chains, hooks, slings, etc., are in good con-
dition and are the correct capacity. Be sure hooks
are positioned correctly. Lifting eyes are not to be
side loaded during a lifting operation.
(10)To avoid burns, be alert for hot parts on machines
which have just been stopped and hot fluids in
lines, tubes and compartments.
(11)Be careful when removing cover plates. Gradually
back off the last two capscrews or nuts located at
opposite ends of the cover or device and carefully
pry cover loose to relieve any spring or other pres-
sure, before removing the last two capscrews or
nuts completely.
(12)Be careful when removing filler caps, breathers and
plugs on the machine. Hold a rag over the cap or
plug to prevent being sprayed or splashed by liq-
uids under pressure. The danger is even greater if
the machine has just been stopped because fluids
can be hot.

5. 0-4
(13)Always use the proper tools that are in good condi-
tion and that are suited for the job at hand. Be sure
you understand how to use them before performing
any service work.
(14)Reinstall all fasteners with the same part number.
Do not use a lesser quality fastener if replacements
are necessary.
(15)Repairs which require welding should be per-
formed only with the benefit of the appropriate ref-
erence information and by personnel adequately
trained and knowledgeable in welding procedures.
Determine type of metal being welded and select
correct welding procedure and electrodes, rods or
wire to provide a weld metal strength equivalent at
least to that of the parent metal. Make sure to dis-
connect battery before any welding procedures are
attempted.
(16)Do not damage wiring during removal operations.
Reinstall the wiring so it is not damaged nor will be
damaged in operation of the machine by contacting
sharp corners, or by rubbing against some object or
hot surface. Do not connect wiring to a line contain-
ing fluid.
(17)Be sure all protective devices including guards and
shields are properly installed and functioning cor-
rectly before starting a repair. If a guard or shield
must be removed to perform the repair work, use
extra caution and replace the guard or shield after
repair is completed.
(18)The maintenance and repair work while holding the
bucket raised is dangerous due to the possibility of
a falling attachment. Don’t fail to lower the attach-
ment and place the bucket to the ground before
starting the work.
(19)Loose or damaged fuel, lubricant and hydraulic
lines, tubes and hoses can cause fires. Do not bend
or strike high pressure lines or install ones which
have been bent or damaged. Inspect lines, tubes
and hoses carefully. Do not check for leaks with
your hands. Very small (pinhole) leaks can result in
a high velocity oil stream that will be invisible close
to the hose. This oil can penetrate the skin and
cause personal injury. Use card-board or paper to
locate pinhole leaks.
(20)Tighten connections to the correct torque. Make
sure that all heat shields, clamps and guards are in-
stalled correctly to avoid excessive heat, vibration
or rubbing against other parts during operation.
Shields that protect against oil spray onto hot ex-
haust components in event of a line, tube or seal
failure must be installed correctly.
(21)Do not operate a machine if any rotating part is
damaged or contacts any other part during opera-
tion. Any high speed rotating component that has
been damaged or altered should be checked for
balance before reusing.
(22)Be careful when servicing or separating the tracks
(crawlers). Chips can fly when removing or install-
ing a track (crawlers) pin. Wear safety glasses and
long sleeve protective clothing. Tracks (crawlers)
can unroll very quickly when separated. Keep away
from front and rear of machine. The machine can
move unexpectedly when both tracks (crawlers)
are disengaged from the sprockets. Block the ma-
chine to prevent it from moving.

6. 0-5
33
34
51
47
26
11
21
46
31
32
25 1
2
3
12
13
22
23
24
Index
No.
Title
Book Code No.
Distribution Year–Month
S5YT0210E01
2010-06
S5YN0129E01
2010-06
S5YT0310E01
2010-06
S5YT1112E01
2010-06
S5YT1210E01
2010-06
S5YT1310E01
2010-06
S5LF2112E01
2010-06
S5YT2210E01
2010-06
S5YT2310E01
2010-06
S5YT2410E01
2010-06
S5LF2511E01
2010-06
S5YN3129E01
2010-06
_
_
S5YT3210E01
2010-06
S5YT3310E01
2010-06
S5YT2610E01
2010-06
S5LF4712E01
2010-06
_
_
S5YT5112E01
2010-06
_
YT06-18001~
S5YT3410E01
2010-06
S5YT4609E01
2010-06
STANDARD MAINTENANCE
TIME SCHEDULE
MAINTENANCE STANDARD
AND TEST PROCEDURE
MECHATRO CONTROLLER
DISASSEMBLING
& ASSEMBLING
CAB INTERFERENCE
PREVENTION SYSTEM
2
1
3
11
12
13
21
22
23
24
25
31
32
33
34
46
47
51
OUTLINE
SPECIFICATIONS
ATTACHMENT DIMENSIONS
TOOLS
HYDRAULIC SYSTEM
ELECTRIC SYSTEM
COMPONENTS SYSTEM
AIR-CONDITIONER SYSTEM
ATTACHMENT
UPPER STRUCTURE
TRAVEL SYSTEM
BY ERROR CODES
BY TROUBLE
ENGINE
APPLICABLE MACHINES
SPECIFICATIONS
MAINTENANCE
SYSTEM
DISASSEMBLING
TROUBLESHOOTING
E
/
G
INDEX 70SR-2
NA
26

7. 33. UPPER SLEWING STRUCTURE
33-90
33.2.3 PILOT VALVE (FOR ATT)
33.2.3.1 CROSS-SECTIONAL VIEW
Pilot valve (For ATT)
Apply Loctite #277 to areas marked **
Note) The parts marked * might not be equipped depending on valve type.
Tightening torque
N-m (lbf-ft)
No. Parts Q'ty
Tightening torque
N-m (lbf-ft)
No. Parts Q'ty
101
151
201-1
201-2
211
Casing
Plate
Spool
Spool
Plug
1
1
2
2
4
*218-1
*218-2
221
241-1
241-2
Seat
Seat
Spring
Spring
Spring
2
2
4
2
2
212
213
214
216-1
216-2
Push rod
Seal
O-ring; 1B P20
Spring seat
Spring seat
4
4
4
2
2
47.1 (35)
68.6 (51)**
*246
301
302
312
501
Spring
Joint: M14
Circular plate
Adjust nut: M14
Boots
4
1
1
1
1
217 Washer 2 (Shim) 4
!
# $
# %!
$!
!
# %!
$!
!
!
'
(
)
* +
, -$ .

8. 33. UPPER SLEWING STRUCTURE
33-91
33
33.2.3.2 DISASSEMBLY
(1) Plug each port of pilot valve, and clean it with
kerosine.
P port: PF1/4
1 to 4 and T port: PF3/8
(2) Fix pilot valve with vise via a protective plate
(Alminum plate etc.), and remove boots (501).
Removing boot (501)
(3) Remove adjusting nut (312) applying spanners to
adjusting nut (312) and circular plate (302).
Tools: Spanner: 22 mm, 32 mm
Removing adjusting nut (312)
(4) Remove circular plate (302)
Tools: Spanner: 32 mm
Removing circular plate (302)
Circular plate is removed
Installing Jig A
501
501
312
302
312
302
302
302

9. 33. UPPER SLEWING STRUCTURE
33-92
When the force of return springs (221) is strong, never loosen joint (301). If loosened, it might result in jumping out
of plate (151), plug (211) and push rod (212).
Remove joint (301) pressing plate (151) downward with two fingers.
To prevent personal injury, plug (211) must be removed slowly and evenly until the return spring (221) force is
completely released.
(5) Turn joint (301) in counterclockwise with Jig A to
remove.
Jig A: See page 33.2.3.7(1).
Tools: Spanner: 24 mm
Removing joint (301)
(6) Remove plate (151)
-When the force of return springs (221) are strong,
press plate to let it come up slowly.
Removing plate (151)
-When the force of return springs (221) are weak, plug
is left in casing (101) due to sliding resistance of O-ring
(214).
Tools: Pull plug (211) out with a flat-blade screw driver.
Removing plug (211)
301
301
151
151
211
211

10. 33. UPPER SLEWING STRUCTURE
33-93
33
Record combination of port holes on casing and the pulled out parts. The stroke differs according to direction.
Never push down spring seat (216-1) in 7 mm (0.276 in) or more. (For port 1,3)
Never push down spring seat (216-2) in 9.4 mm (0.370 in) or more. (For port 2,4)
(7) Remove push rod (212), plug (211), pressure
reducing valve assembly (spool), return springs
(221) from casing (101).
Removing push rod, plug, pressure reducing valve
and spring
(8) Push springs (241-1), (241-2) in the range of 7mm
(0.276in) that the movement of spring seats (216-
1), (216-2) and shift the seats (216) in a side
direction, and remove spools (201-1), (201-2)
through the larger hole of seat.
Removing spool (201)
(9) Remove spool (201-1), (201-2), spring seats (216-
1), (216-2), spring (241-1), (241-2) and washer
(217).
Disassembling pressure reducing valve
221
101
212
211
221
101
212
211
201-1
201-2
201-1
201-2
216-1
216-2
216-1
216-2
201-1
201-2
201-1
201-2
241-1
241-2
241-1
241-2
216-1
216-2
216-1
216-2
217
217

11. 33. UPPER SLEWING STRUCTURE
33-94
The parts marked * might not be equipped depending on valve type.
33.2.3.3 CLEANING PARTS
(1) Clean parts with wash oil roughly.
(2) Clean parts with wash oil completely.
(3) Dry parts by swabbing clean rag.
(4) Apply rust preventives on parts.
(10)Remove spring (*246), spring seat (*218-1), (*218-
2) from push rod (212).
Disassembling push rod
(11)Pull out push rod (212) from plug (211).
(12)Remove O-ring (214) from plug (211).
Removing push rod (212)
Remove inside seal (213) from plug (211) with small driver.
Removing seal (213)
211
212
214
*246
211
212
214
*246
*218-1
*218-2
*218-1
*218-2
212
212
213
213

12. 33. UPPER SLEWING STRUCTURE
33-95
33
33.2.3.4 ASSEMBLING
Never push down spring seat (216-1) in 7mm (0.276in) or more. (For port 1,3)
Never push down spring seat (216-2) in 9.4mm (0.370in) or more. (For port 2,4)
Install the removed respective assembly into respective holes.
(1) Fit washer 2 (217), springs (241-1), (241-2), spring
seats (216-1), (216-2) to spool (201-1), (201-2).
Assembling pressure reducing valve
(2) Push spring (241-1), (241-2) in the range of that the
movement of spring seats (216-1), (216-2) in a side
direction, and install spools (201-1) through the
larger hole of spring seat.
Installing spools (201-1), (201-2)
(3) Place spring (221) into ports 1,3 of casing (101),
and then install pressure reducing valve assembly
in it.
Place springs (221) into ports 2,4 and install it.
Installing pressure reducing valve assembly
217
217
201-1
201-1
201-2
201-2
201-1
201-2
241-1
241-2
241-1
241-2
216-1
216-2
216-1
216-2
216-1
216-2
216-1
216-2
201-1
201-2
201-1
201-2
101
221
101
221
PRESSURE REDUCING
VALVE ASSY
PRESSURE REDUCING
VALVE ASSY

13. 33. UPPER SLEWING STRUCTURE
33-96
(4) Fit O-ring (214) and seal (213) into plug (211).
-Apply hydraulic oil on surface of push rod.
The parts marked * might not be equipped depending on valve type.
(6) Fit plug (211) assembly to casing (101).
Installing O-ring (214) and seal (213)
(5) Insert push rod (212) in plug (211) and install spring
(*246) and spring seat (*218-1) to push rod (212)
on port 1,3 side.
And install spring seat (*218-2) to push rod on port
2,4 side.
Assembling push rod, spring (246) and seat (218)
1. When the force of spring (211) is weak, it stops at
the position where it is pushed in by the sliding
resistance of O-ring (214).
Installing plug assembly
For the assembling
direction of seal (213).
SEAL (213)
PUSH ROD
(212)
PLUG (211)
-RING (214)
Apply hydraulic oil
213
211
214 213
211
214
212 211 246 218-1
212 211 246 218-1
101 211
101 211

14. 33. UPPER SLEWING STRUCTURE
33-97
33
-Screw it in until it comes in contact with 4 push rods (212) equally.
-The exceeding of screw in may cause malfunction of machine.
2. When the force of spring (221) is strong, attach
plate (151) and press 4 push rods by hand at the
same time, and tighten joint (301) temporarily.
-Install spool (201) straight and evenly into the hole
of casing (101).
-Take care so that plug (211) and plate (151) do not
jump out of casing (101).
Installing plug assembly and plate (151)
(7) Install joint (301) on casing (101) with jig A
securely.
Jig A : See 33.2.3.7 JIG.
Tightening torque : 47.1N-m (32.8 to 37.2 lbf-ft)
Installing joint (301)
(8) Install circular plate (302) to joint (301)
(9) Screw adjusting nut (312) in until it touches circular
plate (302), and tighten it applying spanner to stop
circular plate returning.
Tools: Spanner: 32mm
Tools: Socket: 22mm
-Apply Loctite #277 to threads of joint.
Tightening torque: 68.6N-m (51 lbf-ft)
Installing circular plate (302)
151
301
151
301
101
A
A
101
302
312
302
312

15. 33. UPPER SLEWING STRUCTURE
33-98
(10)Apply heat-resisting grease to joint (301) rotating
section and the top of push rod (212).
(11)Cover it with boots.
(12)Spray rust preventives through each port and
attach plug respectively.
Applying grease to joint section and push rod
301
212
GREASE
GREASE
301
212

16. 33. UPPER SLEWING STRUCTURE
33-110
33.2.5.2 DISASSEMBLY AND ASSEMBLY OF SWING MOTOR
(1) Disassembly
Install it in the original position.
1. Remove the relief assembly (70).
Tools: Socket: 27 mm
2. Remove the by-pass valve (100).
Tools: Allen wrench: 8 mm
Removing relief valve assembly and by-pass valve
3. Apply match mark on cover (39) and housing (26).
Maching marks on cover and housing
4. Remove socket bolt (38).
Tools: Allen wrench: 10 mm
Removing cover mounting bolts
70
100
39
MATCHING
MARK
26
39
26
38

17. 33. UPPER SLEWING STRUCTURE
33-111
33
5. Lift up and remove cover (39).
Removing cover
6. Remove snap ring (5) with plier.
7. Remove inner race of needle bearing (6).
Removing bearing (6) inner race
8. Remove the O-ring (9).
Removing O-ring (9)
9. Remove the balance plate (10).
Removing balance plate
39
6
9
10

18. 33. UPPER SLEWING STRUCTURE
33-112
Fit spring in the original position.
The O-ring (7) (8) make it difficult to slide the piston (18) easily from the housing (26). For this reason, use tapped
hole (M6) provided in the piston (18) to remove it, as shown in the above Fig.
10.Remove the bushing (14) with a teflon ring (16) on
it, and the scroll wave (15).
Removing bushing (14) and scrollwave (15)
11.Remove spring (17) from brake piston (18).
Removing spring (17)
12.Remove brake piston (18).
Removing brake piston (18)
14
17
18
18

19. 33. UPPER SLEWING STRUCTURE
33-113
33
-Oil seal (28) and outer race of taper roller bearing (1) are left in housing.
-Take care not to damage the sliding surface on upper section of cylinder housing.
-Assemble piston bore of cylinder (19) and piston assembly (21) in the same original combination.
13.Remove the separator plate (4) and friction plate
(3).
Removing separator plate (4) and friction plate (3)
14.Remove cylinder assembly (19) from housing (26).
Removing cylinder assembly (19)
15.Remove the outer race of tapered roller bearing (1)
from the housing.
Removing outer race of tapered roller bearing (1)
4
3
19
26
1

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21. 33. UPPER SLEWING STRUCTURE
33-114
16.Remove oil seal (28) from housing (26) with driver
and hammer.
-The reuse of the removed oil seal is not allowed.
Removing oil seal (28)
17.Removing the cylinder assembly.
a. Attach an gear puller to two positions of the inner
race of the tapered roller bearing (1) and to the
splined end of the cylinder (19), and pull out the
inner race along with the collar (27).
Pulling inner race of tapered roller bearing (1)
b. Remove the cam plate (23), piston assembly (21)
and return plate (22) together from the cylinder
(19).
Removing cam plate (23), piston assembly (21) and
return plate (22)
c. Remove cam plate (23) from the piston assembly
(21) as is by sliding it on sliding surface of piston
assembly (21).
Removing cam plate (23)
28
26
27
1
23
22
21
21
23

22. 33. UPPER SLEWING STRUCTURE
33-115
33
Handle cam plate with care so as not to damage its sliding surface.
d. Remove retaining spring (20) from cylinder (19).
Removing retaining spring (20)
19 20

23. 33. UPPER SLEWING STRUCTURE
33-116
(2) Installation
Install swing motor unit in the reverse procedure of disassembling.
1. Jigs
Jig used for installing is not provided with part number.
2. Assembling relief assembly
Fit relief assembly (70) to cover (39).
Tools: Socket: 27 mm
Tightening torque : 39 N-m (29 lbf-ft)
Assembling relief assembly (70)
3. Confirming correct assembly
Open the brake release port, apply a pilot pressure
of 1.96 MPa (280 psi) to the P port and confirm that
the output shaft rotates more than 1 turn smoothly
by 19.6~29.4 N-m (14~22 lbf-ft) torque. In case the
output shaft does not rotate, disassemble it again
and readjust.
Confirming correct assembly
Press-fitting jig
for inner race
of tapered
roller bearing (1)
Press-fitting jig
for collar (27)
Press-fitting jig
for oil seal (28)
Seal protector
Dimensions
Jigs Dimensions
Jigs
(2.4350
)
(1.1909±0.0039)
30.25±0.1
35
(1.38)
27
(1.06)
17.5
(0.689)
(0.8720)
22.15
(1.0039±0.0039)
25.5±0.1
(1.9488±0.0039)
49.5±0.1
(1.1417
±0.0039)
29±0.2
30.3
(1.19)
3
(0.008)
60 (2.36)
75 (2.95)
+0
-0.15
+0
-0.00591
+0.1
-0
+0.1
-0
+0.0039
-0
7
(0.276) 50 (1.97)
60 (2.36)
(0.08) 2
10.5 (0.413)
155 (6.10)
13.5
25.2
61.85
25 (0.984)
45 (1.77)
R3
(0.118)
C1
+0.0059
-0
+0.15
-0
(
)
(0.5315 )
+0.0039
-0
(0.9921
)
(0.04)
70
39
Rotate spline by
19.6 to 29.4 N·m
(14 to 22 lbf·ft)
with torque
wrench.
A,B release
(inlet / outlet ports)
Apply pressure 1.96 MPa
(280 psi) to brake release
port (PF 1/4)