This shop manual covers repair and maintenance procedures for Komatsu PC12R-8 and PC15R-8 excavators. It includes sections on general information, structure and function, testing and adjusting, disassembly and assembly, maintenance standards, and other topics. Safety precautions are marked with symbols throughout. The manual should be used along with the latest engine shop manual for these models.
2. 00-2 PC12R, 15R-8
CONTENTS
01 GENERAL ............................................................................................................ 01-1
10 STRUCTURE AND FUNCTION............................................................ 10-1
20 TESTING AND ADJUSTING ................................................................. 20-1
30 DISASSEMBLY AND ASSEMBLY ..................................................... 30-1
40 MAINTENANCE STANDARD ............................................................... 40-1
90 OTHERS ............................................................................................................... 90-1
No. of page
2
3. SAFETY SAFETY NOTICE
SAFETY
SAFETY NOTICE
IMPORTANT SAFETY NOTICE
Proper service and repair is extremely important for safe machine operation. The
service and repair techniques recommended by Komatsu and described in this manual
are both effective and safe. Some of these techniques require the use of tools specially
designed by Komatsu for the specific purpose.
To prevent injury to workers, the symbol A is used to mark safety precautions in this
manual. The cautions accompanying these symbols should always be followed care-
fully. If any dangerous situation arises or may possibly arise, first consider safety, and
take the necessary actions to deal with the situation.
GENERAL PRECAUTIONS
Mistakes in operation are extremely dangerous.
Read the Operation and Maintenance Manual
carefully BEFORE operating the machine.
1. Before carrying out any greasing or repairs,
read all the precautions given on the decals
which are fixed to the machine.
2. When carrying out any operation, always
wear safety shoes and helmet. Do not wear
loose work clothes, or clothes with buttons
missing.
. Always wear safety glasses when hitting
parts with a hammer.
. Always wear safety glasses when grind-
ing parts with a grinder, etc.
3. If welding repairs are needed, always have a
4.
5.
trained, experienced welder carry out the
work. When carrying out welding work, al-
ways wear welding gloves, apron, hand
shield, cap and other clothes suited for weld-
ing work.
When carrying out any operation with two
or more workers, always agree on the oper-
ating procedure before starting. Always in-
form your fellow workers before starting any
step of the operation. Before starting work,
hang UNDER REPAIR signs on the controls
in the operator’s compartment.
Keep all tools in good condition and learn
the correct way to use them.
6. Decide a place in the repair workshop to
keep tools and removed parts. Always keep
the tools and parts in their correct places.
Always keep the work area clean and make
sure that there is no dirt or oil on the floor.
Smoke only in the areas provided for smok-
ing. Never smoke while working.
PREPARATIONS FOR WORK
7.
8.
Before adding oil or making any repairs,
park the machine on hard, level ground, and
block the wheels or tracks to prevent the
machine from moving.
Before starting work, lower blade, ripper,
bucket or any other work equipment to the
ground. If this is not possible, insert the
safety pin or use blocks to prevent the work
equipment from falling. In addition, be sure
to lock all the control levers and hang warn-
ing signs on them.
9. When disassembling or assembling, support
the machine with blocks, jacks or stands
before starting work.
10. Remove all mud and oil from the steps or
other places used to get on and off the ma-
chine. Always use the handrails, ladders or
steps when getting on or off the machine.
Never jump on or off the machine. If it is
impossible to use the handrails, ladders or
steps, use a stand to provide safe footing.
00-3
4. SAFETY SAFETY NOTICE
PRECAUTIONS DURING WORK
11.
12.
13.
When removing the oil filler cap, drain plug
or hydraulic pressure measuring plugs,
loosen them slowly to prevent the oil from
spurting out.
Before disconnecting or removing compo-
nents of the oil, water or air circuits, first
remove the pressure completely from the
circuit.
The water and oil in the circuits are hot
when the engine is stopped, so be careful
not to get burned.
Wait for the oil and water to cool before
carrying out any work on the oil or water
circuits.
Before starting work, remove the leads from
the battery. Always remove the lead from
the negative (-1 terminal first.
14. When raising heavy components, use a hoist
15.
16.
17.
18.
or crane.
Check that the wire rope, chains and hooks
are free from damage.
Always use lifting equipment which has
ample capacity.
Install the lifting equipment at the correct
places. Use a hoist or crane and operate
slowly to prevent the component from hit-
ting any other part. Do not work with any
part still raised by the hoist or crane.
When removing covers which are under in-
ternal pressure or under pressure from a
spring, always leave two bolts in position
on opposite sides. Slowly release the pres-
sure, then slowly loosen the bolts to remove.
When removing components, be careful not
to break or damage the wiring. Damaged
wiring may cause electrical fires.
When removing piping, stop the fuel or oil
from spilling out. If any fuel or oil drips onto
the floor, wipe it up immediately. Fuel or oil
on the floor can cause you to slip, or can
even start fires.
As a general rule, do not use gasoline to
wash parts. In particular, use only the mini-
mum of gasoline when washing electrical
parts.
19. Be sure to assemble all parts again in their
original places.
Replace any damaged parts with new parts.
. When installing hoses and wires, be sure
that they will not be damaged by contact
with other parts when the machine is be-
ing operated.
20. When installing high pressure hoses, make
sure that they are not twisted. Damaged
tubes are dangerous, so be extremely care-
ful when installing tubes for high pressure
circuits. Also, check that connecting parts
are correctly installed.
21. When assembling or installing parts, always
use the specified tightening torques. When
installing protective parts such as guards,
or parts which vibrate violently or rotate at
high speed, be particularly careful to check
that they are installed correctly.
22. When aligning two holes, never insert your
fingers or hand. Be careful not to get your
fingers caught in a hole.
23. When measuring hydraulic pressure, check
that the measuring tool is correctly assem-
bled before taking any measurements.
24. Take care when removing or installing the
tracks of track-type machines.
When removing the track, the track sepa-
rates suddenly, so never let anyone stand at
either end of the track.
00-d.
5. FOREWORD GENERAL
FOREWORD
GENERAL
This shop manual has been prepared as an aid to improve the quality of repairs by giving the
serviceman an accurate understanding of the product and by showing him the correct way to perform
repairs and make judgements. Make sure you understand the contents of this manual and use it to full
effect at every opportunity.
This shop manual mainly contains the necessary technical information for operations performed in a
service workshop. For ease of understanding, the manual is divided into the following chapters; these
chapters are further divided into the each main group of components.
STRUCTURE AND FUNCTION
This section explains the structure and function of each component. It serves not only to give
an understanding of the structure, but also serves as reference material for troubleshooting.
TESTING AND ADJUSTING
This section explains checks to be made before and after performing repairs, as well as
adjustments to be made at completion of the checks and repairs.
Troubleshooting charts correlating “Problems” to “Causes” are also included in this section.
DISASSEMBLY AND ASSEMBLY
This section explains the order to be followed when removing, installing, disassembling or
assembling each component, as well as precautions to be taken for these operations.
MAINTENANCE STANDARD
This section gives the judgement standards when inspecting’disassembled parts.
NOTICE
The specifications contained in this shop manual are subject to change at any
time and without any advance notice. Use the specifications given in the book
with the latest date.
00-5
6. FOREWORD HOW TO READ THE SHOP MANUAL
HOW TO READ THE SHOP MANUAL
VOLUMES
Shop manuals are issued as a guide to carrying
out repairs. They are divided as follows:
Chassis volume: Issued for every machine model
Engine volume: Issued for each engine series
Electrical volume:
I
Each issued as one
Attachments volume: volume to cover all
models
These various volumes are designed to avoid
duplicating the same information. Therefore, to
deal with all repairs for any model , it is neces-
sary that chassis, engine, electrical and attach-
ment volumes be available.
DISTRIBUTION AND UPDATING
Any additions,, amendments or other changes
will be sent to KOMATSU distributors. Get the
most up-to-date information before you start any
work.
FILING METHOD
See the page number on the bottom of the
page. File the pages in correct order.
Following examples show how to read the
page number.
Example 1 (Chassis volume):
10 -3
Item number (IO. Structure
and Function)
Consecutive page number for
each item.
Example 2 (Engine volume):
12 - 5
TT T
Unit number (I. Engine)
Item number (2. Testing and
Adjusting)
Consecutive page number for
each item.
Additional pages: Additional pages are indi-
cated by a hyphen 6) and number after the
page number. File as in the example.
Example:
IO-4 12-203
REVISED EDITION MARK
When a manual is revised, an edition mark
(@@@....I is recorded on the bottom of the
pages.
REVISIONS
Revised pages are shown in the LIST OF RE-
VISED PAGES next to the CONTENTS page.
SYMBOLS
So that the shop manual can be of ample prac-
tical use, important safety and quality portions
are marked with the following symbols.
Symbol 1 Item
A/Safety
* ICaution
Weight
Tightenin:
w torque
+
& Coat
Remarks
Special safety precautions are
necessary when performing
the work.
Special technical precautions
or other precautions for pre-
serving standards are neces-
sary when performing the
work.
Weight of parts of systems.
Caution necessary when se-
lecting hoisting wire, or when
working posture is important,
etc.
Places that require special at-
tention for the tightening
torque during assembly.
Places to be coated with ad-
hesives and lubricants, etc.
Places where oil, water or fuel
must be added, and the ca-
pacity.
Places where oil or water
must be drained, and quan-
tity to be drained.
10-4-I -
1O-4-2
> Added pages -c~~~~~~::
1o-5 12-204
00-6
7. FOREWORD HOISTING INSTRUCTIONS
HOISTING INSTRUCTIONS
HOISTING
Heavy parts (25 kg or more) must be
lifted with a hoist, etc. In the DISAS-
SEMBLY AND ASSEMBLY section,
every part weighing 25 kg or more is
indicated clearly with the symbol &
. If a part cannot be smoothly removed from
the machine by hoisting, the following checks
should be made:
I) Check for removal of all bolts fastening
the part to the relative parts.
2) Check for existence of another part caus-
ing interference with the part to be re-
moved.
WIRE ROPES
1) Use adequate ropes depending on the
weight of parts to be hoisted, referring to
the table below:
Wire ropes
(Standard “Z” or “S” twist ropes
without galvanizing)
Rope diameter
mm
10
11.2
12.5
14
16
18
20
22.4
30
40
50
60
l- Allowable load
kN tons
9.8 1.0
13.7 1.4
15.7 1.6
21.6 2.2
27.5 2.8
35.3 3.6
43.1 4.4
54.9 5.6
98.1 10.0
176.5 18.0
274.6 28.0
392.2 40.0
Ir The allowable load value is estimated to
be one-sixth or one-seventh of the break-
ing strength of the rope used.
2) Sling wire ropes from the middle portion
of the hook.
Slinging near the edge of the hook may
cause the rope to slip off the hook during
hoisting, and a serious accident can re-
sult. Hooks have maximum strength at
the middle portion.
100% 88% 79% 71% 41%
SAD00479
3) Do not sling a heavy load with one rope
alone, but sling with two or more ropes
symmetrically wound onto the load.
A Slinging with one rope may cause
turning of the load during hoisting,
untwisting of the rope, or slipping of
the rope from its original winding
position on the load, which can re-
sult in a dangerous accident.
4) Do not sling a heavy load with ropes form-
ing a wide hanging angle from the hook.
When hoisting a load with two or more
ropes, the force subjected to each rope
will increase with the hanging angles. The
table below shows the variation of allow-
able load kN {kg) when hoisting is made
with two ropes, each of which is allowed
to sling up to 9.8 kN {IO00 kg) vertically,
at various hanging angles.
When two ropes sling a load vertically, up
to 19.6 kN (2000 kg) of total weight can be
suspended. This weight becomes 9.8 kN
(1000 kg) when two ropes make a 120”
hanging angle. On the other hand, two
ropes are subjected to an excessive force
as large as 39.2 kN (4000 kg) if they sling
a 19.6 kN (2000 kg) load at a lifting angle
of 150”.
L I I I I I
30 60 90 120 150
Lifting mole (deereel SAD00480
00-7
8. FOREWORD METHOD OF DISASSEMBLING, CONNECTING PUSH-PULL TYPE COUPLER
METHOD OF DISASSEMBLING, CONNECTlNG PUSH-PULL TYPE COUPLER
* There are 2 types of push-pull type coupler. The method of disassembling and connecting is differ-
ent, so see the table below when disassembling and connecting the coupler.
Type1
1) Hold the mouthpiece of the tightening por-
tion and push body (2) in straight until slid-
ing prevention ring (1) contacts contact sur-
face a of the hexagonal portion at the male
end.
CWPOfi391
2) Hold in the condition in Step I), and push
until cover (3) contacts contact surface a of
the hexagonal portion at the male end.
CWPO6393
Hold in the condition in Steps 1) and 21,and
pull out whole body (2) to disconnect it.
CWPO6395
Type2
1) Hold the mouthpiece of the tightening por-
tion and push body (2) in straight until slid-
ing prevention ring (I) contacts contact sur-
face a of the hexagonal portion at the male
end.
CWPO6392
2) Hold in the condition in Step I), and turn
lever (4) to the right (clockwise).
CWPO6394
3) Hold in the condition in Steps 1) and 21,and
pull out whole body (2) to disconnect it.
CWPO6396
00-8
9. FOREWORD METHOD OF DISASSEMBLING, CONNECTING PUSH-PULL TYPE COUPLER
Type1 Me 2
l Hold the mouthpiece of the tightening por- l Hold the mouthpiece of the tightening por-
tion and push body (2) in straight until slid- tion and push body (2) in straight until slid-
ing prevention ring (I) contacts contact sur- ing prevention ring (I) contacts contact sur-
face a of the hexagonal portion at the male face a of the hexagonal portion at the male
end to connect it. end to connect it.
S
‘L
:
E
8
CWP06391 CWP06392
00-9
10. DISASSEMBLY AND ASSEMBLY STARTING MOTOR
REMOVAL OF STARTING
MOTOR ASSEMBLY
A Disconnect the cable from the negative (-1 ter-
minal of the battery.
Open the operator’s seat, then remove storage
box (I).
Disconnect wiring connector E2 (2) and battery
terminal (3).
Remove starting motor assembly (4).
INSTALLATION OF STARTING
MOTOR ASSEMBLY
. Carry out installation in the reverse order to re-
moval.
I - 3 I
PC12R, 15R-8 30-7
0
11. DISASSEMBLY AND ASSEMBLY ALTERNATOR
REMOVAL OF ALTERNATOR
ASSEMBLY
A Disconnect the cable from the negative (-1 ter-
minal of the battery.
1. Open the operator’s seat, then remove storage
box (I).
2. Disconnect wiring connector E3 (2).
3. Loosen the mounting nut and adjustment bolt,
then remove fan belt (3) from the pulley. jl
4. Remove alternator assembly (4).
INSTALLATION OF
ALTERNATOR ASSEMBLY
l Carry out installation in the reverse order to re-
moval.
+ Adjust the fan belt tension. For details, see
TESTING AND ADJUSTING, Testing and ad-
justing fan belt tension.
30-8
0
PC12R, 15R-8
12. DISASSEMBLY AND ASSEMBLY FUEL INJECTION PUMP
REMOVAL OF FUEL INJECTION PUMP
ASSEMBLY
4h Disconnect the cable from the negative H ter-
minal of the battery.
1. Disconnect fuel feed hose (I 1,return hose (21, and
spill hose (3).
2. Remove fuel injection tube (4). m
3. Remove cover (5).
4. Pull out pin (6) to disconnect the rod.
* Block the gaps with cloth, etc. to prevent the
pin from failing in the pump housing.
5. Remove fuel injection pump assembly (7). m
NSTALLATION OF FUEL
INJECTION PUMP ASSEMBLY
l Carry out installation in the reverse order to re-
moval.
w Fuel injection tube sleeve nut :
31.85 f 2.45 Nm (3.25 * 0.25 kgml
Ir Adjust the fuel injection timing. For details,
see TESTING AND ADJUSTING, Testing and
adjusting fuel injection timing.
5
CBPO3306 CBPO3307
PC12R, 15R-8 30-9
a
13. DISASSEMBLY AND ASSEMBLY NOZZLE HOLDER
REMOVAL OF NOZZLE HOLDER
ASSEMBLY
1. Remove air intake hose and air cleaner assembly
(I).
2. Remove air cleaner case bracket (2).
3. Remove fuel injection tube (3). m
4. Remove blow-by hose (4).
5. Disconnect spill .hose (5).
6. Remove nozzle holder assembly (6). m
INSTALLATION OF NOZZLE
HOLDER ASSEMBLY
. Carry out installation in the reverse order to re-
moval.
QGI Fuel injection tube sleeve nut :
31.85 + 2.45 Nm I3.25 f 0.25 kgm}
m Nozzle holder :
50.96 f 1.96 Nm {5.2 + 0.2 kgm}
30-10
0
PC12R, 15R-8
14. DISASSEMBLY AND ASSEMBLY WATER PUMP
REMOVAL OF WATER PUMP
ASSEMBLY
&h Disconnect the cable from the negative (-) ter-
minal of the battery.
1.
2.
3.
4.
5.
6.
7.
8.
9.
IO.
11.
Drain the cooling water.
Remove the engine hood.
Remove air intake hose and air cleaner assembly
(1).
Remove air cleaner case bracket (2).
Disconnect radiator inlet hose (3) and outlet hose
(4).
Disconnect water temperature sensor wiring con-
nector E6 (5).
Remove fan guard (6).
Disconnect fan shroud (7) and move it toward the
engine.
Loosen the fan belt. For details, see REMOVAL
OF ALTERNATOR ASSEMBLY. m
Remove fan (8), then remove fan belt (9).
Disconnect alternator adjustment bar (IO) from the
alternator.
12. Remove water pump assembly (1 I).
INSTALLATION OF WATER
PUMP ASSEMBLY
l Carry out installation in the reverse order to re-
moval.
* Adjust the fan belt tension. For details, see
TESTING AND ADJUSTING, Testing and ad-
justing fan belt tension.
. Refilling with water
Add water through the water filler to the speci-
fied level. Run the engine to circulate the water
through the system. Then, check the water level
again.
PC12R, 15R-8
15. DISASSEMBLY AND ASSEMBLY THERMOSTAT
REMOVAL OF THERMOSTAT
ASSEMBLY
1. Drain the cooling water.
2. Remove air intake hose and air cleaner assembly
(1).
3. Disconnect radiator inlet hose (2).
4. Remove cover (31, then remove thermostat as-
sembly.
INSTALLATION OF
. Carry out installation in the reverse order to re-
moval.
. Refilling with water
Add water through the water filler to the speci-
fied level. Run the engine to circulate the water
through the system. Then, check the water level
again.
30-12
0
PC12R, 15R-8
16. DISASSEMBLY AND ASSEMBLY ENGINE FRONT SEAL
REMOVAL OF ENGINE FRONT
SEAL
I. Remove the radiator assembly. For details, see
REMOVAL OF RADIATOR ASSEMBLY.
2. Loosen the mounting bolt and adjustment bolt of
the alternator, and loosen the fan belt.
3. Remove fan belt (I).
4. Remove the crank pulley mounting bolt.
5. Remove crank pulley (2) with pulier 0.
6. Remove engine front seal (3).
INSTALLATION OF ENGINE
FRONT SEAL
. Carry out installation in the reverse order to re-
moval.
* Adjust the fan belt tension. For details, see
TESTING AND ADJUSTING, Testing and ad-
justing fan belt tension.
m Crank pulley mounting bolt :
88.2 ? 4.9 Nm (9 ? 0.5 kgm}
M
* When installing the crank pulley, match it to
the dowel pin of the crankshaft.
& Oil seal lip : Engine oil (E030-CD)
PC12R, 15R-8 30-l 3
0
17. DISASSEMBLY AND ASSEMBLY ENGINE REAR SEAL
REMOVAL OF ENGINE REAR
SEAL
1. Remove the damper assembly. For details, see
REMOVAL OF DAMPER ASSEMBLY.
2. Remove flywheel (1). m
3. Remove seal case (2).
* Insert screwdrivers, etc. in the cuts on both
ends of the seal case, and pry up.
CBPO3322
Remove engine rear seal (3) from the seal case.
m
CBP03323
30-l 4
0
PC12R, 15R-8
18. DISASSEMBLY AND ASSEMBLY ENGINE REAR SEAL
INSTALLATION OF ENGINE
REAR SEAL
. Carry out installation in the reverse order to re-
moval.
m
& Seal fitting face of seal case and oil seal
lip : Engine oil (E030-CD)
* Press fit the oil seal until it is flush with the
seal case.
& Fitting face of seal case:
Gasket sealant (LG-7)
a
* Tighten the flywheel mounting bolts in the or-
der shown at right.
w Flywheel mounting bolt :
93.3 f 2.94 Nm I8.5 f 0.3 kgm}
After installing the flywheel, check it for facial
runout and radial runout with dial gauge 0.
. Facial runout : 0.20 mm max.
. Radial runout : 0.20 mm max.
CKP02631
PC12R, 15R-8 30-l 5
0
19. DISASSEMBLY AND ASSEMBLY CYLINDER HEAD
REMOVAL OF CYLINDER HEAD
ASSEMBLY
&b Disconnect the cable from the negative (-) ter-
minal of the battery.
1.
2.
3.
4.
5.
Remove the water pump assembly. For details,
see REMOVAL OF WATER PUMP ASSEMBLY.
Disconnect fuel filter (1) and move it toward the
counterweight.
Remove 3 fuel tubes (2). m
Remove blow-by hose (3).
Remove exhaust pipe (4) and muffler (5).
Sr After removing the exhaust pipe and muffler
as an assembly, separate them from each
other, then take out of the engine room.
6. Remove air intake manifold (6).
7. Remove exhaust manifold (7).
8. Disconnect 3 spill hoses (8).
9. Remove 3 nozzle holder assemblies (9). m
10. Remove glow plug harness (IO).
125
CBP03328
30-16
a
PC12R, 15R-8
20. Thank you very much for
your reading. Please Click
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21. DISASSEMBLY AND ASSEMBLY CYLINDER HEAD
11. Remove glow plugs (II).
12. Remove cylinder head cover (12).
13. Remove rocker shaft and rocker arm assembly
(13). /x
Sr Loosen the locknut, then loosen adjustment
screw by 2 - 3 turns.
14. Remove 6 push rods (14).
15. Remove cylinder head assembly (15). m
INSTALLATION OF CYLINDER
HEAD ASSEMBLY
0 Carry out installation in the reverse order to re-
moval.
w Fuel injection tube sleeve nut :
31.85 f 2.45 Nm I3.25 k 0.25 kgm)
w Nozzle holder :
50.96 i 1.96 Nm 15.2 ? 0.2 kgm}
w Glow plug :
17.15 + 2.45 Nm Il.75 * 0.25 kgm1
m
*
*
*
a
*
Tighten the mounting bolts from the central
one to outer ones in order.
Check that the ball of the adjustment screw is
fitted to the socket of the push rod.
Adjust the valve clearance. For details, see
TESTING AND ADJUSTING, Adjusting valve
clearance.
Tighten the mounting bolts of the cylinder
head assembly in the order shown at right.
I
A : Cam side
B : Fuel injection pump side
C : Flywheel side
D : Gear case side
m Cylinder head assembly mounting bolts :
39.2 ? 1.96 Nm (4 k 0.2 kgm} DXP00901
PC1ZR, 15R-8 30-l 7
22. DISASSEMBLY AND ASSEMBLY RADIATOR
REMOVAL OF RADIATOR
ASSEMBLY
1.
2.
3.
Drain the cooling water.
Remove engine hood (I 1.
Lift off right protector (2).
fblkg Right protector : 30 kg
4.
5.
Remove air intake hose (3).
Disconnect radiator inlet hose (4) and outlet hose
(5).
6. Disconnect reservoir tank hose (6).
7. Remove fan guard (7).
8. Disconnect fan shroud (8) and move it toward the
engine.
9. Disconnect hydraulic oil cooler assembly (9) from
the radiator bracket.
* Do not disconnect the piping.
CBP03334
30-l 8
0
PC12R, 15R-8
23. DISASSEMBLY AND ASSEMBLY RADIATOR
10. Remove radiator assembly (IO).
* Remove the 4 mounting bolts on both sides
of the radiator bracket, then pull out the ra-
diator assembly toward the rear of the ma-
chine.
INSTALLATION OF RADIATOR
ASSEMBLY
l Carry out installation in the reverse order to re-
moval.
. Refilling with water
Add water through the water filler to the speci-
fied level. Run the engine to circulate the water
through the system. Then, check the water level
again.
PC12R, 15R-8 30-19
0
