PDF Shop Manual Komatsu D155AX-6 Crawler Bulldozer - 7 MB
This is the complete shop manual for the Komatsu D155AX-6 Crawler Bulldozer.
It contains in-depth information on maintenance, troubleshooting, and repair procedures.
With detailed diagrams and step-by-step instructions, this manual is the ultimate guide for service technicians to keep the dozer in optimal condition.
It covers everything from the engine and transmission to the undercarriage and hydraulics.
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--- Page 1 ---
SEN00596-22
BULLDOZER D155AX -6
SERIAL NUMBERS 80001 and up
--- Page 3 ---
SEN00599-04 00 Index and foreword
Safety notice 1
(Rev. 2008/08)
Important safety notice
Proper service and repair are 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 k is used to mark safety precautions in this manual. The
cautions accompanying these symbols should always be followed carefully. If any dangerous situa-
tion arises or may possibly arise, first consider safety, and take the necessary actions to deal with
the situation.
1. General precautions 7) If welding repairs are needed, always
k Mistakes in operation are extremely have a trained and experienced welder
dangerous. Read the Operation and carry out the work. When carrying out
Maintenance Manual carefully before w elding work, alw ays wear welding
operating the machine. In addition, gloves, apron, shielding goggles, cap and
read this manual and understand its other clothes suited for welding work.
contents before starting the work. 8) Before starting work, warm up your body
1) Before carrying out any greasing or thoroughly to start work under good condi-
repairs, read all the safety labels stuck to tion.
the machine. For the locations of the 9) Avoid continuing work for long hours and
safety labels and detailed explanation of take rests at proper intervals to keep your
precautions, see the Operation and Main- body in good condition. Take rests in
tenance Manual. specified safe places.
2) Decide a place in the repair workshop to
keep tools and removed parts. Always Safety points
keep the tools and parts in their correct
places. Always keep the work area clean 1 Good arrangement
and make sure that there is no dirt, water, 2 Correct work clothes
or oil on the floor. Smoke only in the areas 3 Following work standard
provided for smoking. Never smoke while
working. 4 Making and checking signs
3) When carrying out any operation, always Prohibition of operation and handling by
5
wear safety shoes and helmet. Do not unlicensed workers
wear loose work clothes, or clothes with 6 Safety check before starting work
buttons missing.
q Always wear safety glasses when hit- Wearing protective goggles
7
(for cleaning or grinding work)
ting parts with a hammer.
q Always wear safety glasses when Wearing shielding goggles and protectors
8
grinding parts with a grinder, etc. (for welding work)
4) When carrying out any operation with 2 or 9 Good physical condition and preparation
more workers, always agree on the oper- Precautions against work which you are
ating procedure before starting. Always 10
not used to or you are used to too much
inform your fellow workers before starting
any step of the operation. Before starting
work, hang UNDER REPAIR warning
signs in the operator's compartment.
5) Only qualified workers must carry out work
and operation which require license or
qualification.
6) Keep all tools in good condition, learn the
correct way to use them, and use the
proper ones of them. Before starting work,
thoroughly check the tools, machine, fork-
lift, service car, etc.
2 D155AX-6
--- Page 4 ---
00 Index and foreword SEN00599-04
3. Push lock type
q 95, 107, 114 engines
Example)
Fuel pressure sensor in common rail
(BOSCH-03)
Disconnect connector (3) according to the fol-
lowing procedure.
1) While pressing lock (C), pull out connector
(3) in the direction of the arrow.
q 114 engine
q 107, 114 engines
Example)
Intake air pressure/temperature sensor in
intake manifold
(SUMITOMO-04)
3) While pressing lock (D), pull out connector
(4) in the direction of the arrow.
q 107 engine
a If the lock is on the underside, use
flat-head screwdriver [1] since you
cannot insert your fingers.
2) While pressing up lock (C) of the connec-
tor with flat-head screwdriver [1], pull out
connector (3) in the direction of the arrow.
D155AX-6 21
--- Page 5 ---
SEN00599-04 00 Index and foreword
Temperature
Fahrenheit-Centigrade conversion: A simple way to convert a Fahrenheit temperature reading into a Centi-
grade temperature reading or vice versa is to enter the accompanying table in the center (boldface column)
of figures. These figures refer to the temperature in either Fahrenheit or Centigrade degrees.
When convert from Fahrenheit to Centigrade degrees, consider the center column to be a table of Fahren-
heit temperatures and read the corresponding Centigrade temperature in the column at the left.
When convert from Centigrade to Fahrenheit degrees, consider the center column to be a table of Centi-
grade values, and read the corresponding Fahrenheit temperature on the right.
1Β°C = 33.8Β°F
Β°C Β°F Β°C Β°F Β°C Β°F Β°C Β°F
β40.4 β40 β40.0 β11.7 11 51.8 7.8 46 114.8 27.2 81 177.8
β37.2 β35 β31.0 β11.1 12 53.6 8.3 47 116.6 27.8 82 179.6
β34.4 β30 β22.0 β10.6 13 55.4 8.9 48 118.4 28.3 83 181.4
β31.7 β25 β13.0 β10.0 14 57.2 9.4 49 120.2 28.9 84 183.2
β28.9 β20 β4.0 β9.4 15 59.0 10.0 50 122.0 29.4 85 185.0
β28.3 β19 β2.2 β8.9 16 60.8 10.6 51 123.8 30.0 86 186.8
β27.8 β18 β0.4 β8.3 17 62.6 11.1 52 125.6 30.6 87 188.6
β27.2 β17 1.4 β7.8 18 64.4 11.7 53 127.4 31.1 88 190.4
β26.7 β16 3.2 β7.2 19 66.2 12.2 54 129.2 31.7 89 192.2
β26.1 β15 5.0 β6.7 20 68.0 12.8 55 131.0 32.2 90 194.0
β25.6 β14 6.8 β6.1 21 69.8 13.3 56 132.8 32.8 91 195.8
β25.0 β13 8.6 β5.6 22 71.6 13.9 57 134.6 33.3 92 197.6
β24.4 β12 10.4 β5.0 23 73.4 14.4 58 136.4 33.9 93 199.4
β23.9 β11 12.2 β4.4 24 75.2 15.0 59 138.2 34.4 94 201.2
β23.3 β10 14.0 β3.9 25 77.0 15.6 60 140.0 35.0 95 203.0
β22.8 β9 15.8 β3.3 26 78.8 16.1 61 141.8 35.6 96 204.8
β22.2 β8 17.6 β2.8 27 80.6 16.7 62 143.6 36.1 97 206.6
β21.7 β7 19.4 β2.2 28 82.4 17.2 63 145.4 36.7 98 208.4
β21.1 β6 21.2 β1.7 29 84.2 17.8 64 147.2 37.2 99 210.2
β20.6 β5 23.0 β1.1 30 86.0 18.3 65 149.0 37.8 100 212.0
β20.0 β4 24.8 β0.6 31 87.8 18.9 66 150.8 40.6 105 221.0
β19.4 β3 26.6 0 32 89.6 19.4 67 152.6 43.3 110 230.0
β18.9 β2 28.4 0.6 33 91.4 20.0 68 154.4 46.1 115 239.0
β18.3 β1 30.2 1.1 34 93.2 20.6 69 156.2 48.9 120 248.0
β17.8 0 32.0 1.7 35 95.0 21.1 70 158.0 51.7 125 257.0
β17.2 1 33.8 2.2 36 96.8 21.7 71 159.8 54.4 130 266.0
β16.7 2 35.6 2.8 37 98.6 22.2 72 161.6 57.2 135 275.0
β16.1 3 37.4 3.3 38 100.4 22.8 73 163.4 60.0 140 284.0
β15.6 4 39.2 3.9 39 102.2 23.3 74 165.2 62.7 145 293.0
β15.0 5 41.0 4.4 40 104.0 23.9 75 167.0 65.6 150 302.0
β14.4 6 42.8 5.0 41 105.8 24.4 76 168.8 68.3 155 311.0
β13.9 7 44.6 5.6 42 107.6 25.0 77 170.6 71.1 160 320.0
β13.3 8 46.4 6.1 43 109.4 25.6 78 172.4 73.9 165 329.0
β12.8 9 48.2 6.7 44 111.2 26.1 79 174.2 76.7 170 338.0
β12.2 10 50.0 7.2 45 113.0 26.7 80 176.0 79.4 175 347.0
40 D155AX-6
--- Page 6 ---
10 Structure, function and maintenance standard SEN00603-01
1. Overflow hose
2. Air bleed hose
3. Inlet hose
4. Coolant filler cap
5. Radiator core assembly
6. Reservoir tank
7. Inlet hose (for circulating at low coolant
temperature)
8. Outlet hose
9. Lower tank (power train oil cooler built-in)
10. Fan
11. Drain plug
12. Cushion
13. Breather cap
14. Pressure valve
a: Aftercooler
b: Aftercooler outlet hose
c: Aftercooler inlet hose
Outline
q The reservoir tank is provided for radiator.
q The power train oil cooler is built in the lower
tank of the radiator.
Radiator
Rectangle
Core type
wave fin
Fin pitch (mm) 4.0
Heat dissipation area (m )
2 41.99 x 2
Relief
(MPa {kg/cm2}) 0.09 {0.9}
Pressure pressure
valve Vacuum
(MPa {kg/cm2}) 0.005 {0.05}
pressure
Specification
Aftercooler: Rectangle wave fin 8.0/2P
D155AX-6 3
--- Page 7 ---
SEN00604-03 10 Structure, function and maintenance standard
Power train skeleton 1
Outline
q The power generated by engine (1) has its tor- q The power transmitted to the bevel gear shaft
sional vibration dampened by damper (2), and is transmitted to HSS (Hydrostatic Steering
then passes through universal joint (3), and is System) (11). Hydraulic, HSS pump (5) is
transmitted to torque converter (8). driven by PTO (6), and output oil of the
q The power from the engine is transmitted Hydraulic, HSS pump drives HSS motor (12).
through the oil by torque converter (8) to the The rotation of the pair of the HSS gears on
transmission input shaft (turbine shaft) in the right and left is controlled by HSS motor
accordance with the change in load. (with L/U) (12). The steering is carried out by generating
q Transmission (9) uses a combination of a plan- a difference in speed on the right and left. It is
etary gear system and hydraulic clutches to also possible to use the HSS mechanism to
reduce the speed and shift the gears (3 for- rotate the right and left sides in opposite direc-
ward gears and 3 reverse gears). It connects tions to carry out pivot turns.
2 sets of clutches selected according to the q Brake (13) of the HSS is used for braking the
change in load, and transmits the power to machine. Brake (13) is a wet, multiple disc
bevel gear (10) from the bevel pinion at the clutch, spring boosted type. The power sent
rear end of the transmission. from brake (13) is transmitted to final drive
(14).
q Final drive (14) consists of a single-stage spur
gear and a single-stage planetary gear system.
It reduces the speed and rotates sprocket (15)
to drive track shoe (16) and move the machine.
It also rotates cooling fan motor (18) with the
oil discharged from cooling fan pump (17)
driven with PTO (6).
2 D155AX-6
--- Page 8 ---
10 Structure, function and maintenance standard SEN00604-03
ECMV for lockup clutch Operation
Outline When traveling in torque converter range
q This valve is used to switch the clutch in order
to regulate the clutch oil pressure to the set
pressure.
Since the modulation waveform is used for the
pressure application characteristics to the
clutch, ECMV is capable of connecting the
lockup clutch smoothly, thereby reducing
shocks resulting from gear shift. Above also
prevents generation of peak torque in the
power train. These arrangements make the
machine comfortable to operator and enhance
durability of the power train.
When changing from torque converter travel to
direct travel
$ 7 *
q When traveling in torque converter range, cur-
rent is not supplied to proportional solenoid (1).
Pressure control valve (3) drains the oil from
clutch port (A) through drain port (T), and
lockup clutch is βreleasedβ.
Also at this time, fill switch (5) is turned βoffβ
At gear shift (in direct travel) because oil pressure is not applied to pressure
detection valve (4).
D155AX-6 21
--- Page 9 ---
SEN00604-03 10 Structure, function and maintenance standard
Forward 3rd speed
40 D155AX-6
--- Page 10 ---
10 Structure, function and maintenance standard SEN00605-03
1. PCCS lever Outline
2. Power train controller q HSS system is an abbreviation for the Hydro-
3. Control valve static Steering System.
4. Hydraulic, HSS pump q The HSS system consists of a set of control
5. Engine valve, hydraulic, HSS pump, and HSS motor
6. EPC valve as shown in the figure. It turns the machine
7. Hydraulic tank continuously without lowering the travel speed
8. Sprocket by making a difference in speed between both
9. Final drive tracks.
10. HSS motor q The power train controller controls the EPC
11. HSS open circuit valve of the control valve to control the revolv-
12. Servo valve ing direction and revolving speed of the HSS
13. Engine throttle controller motor according to the tilting direction and
angle of the PCCS lever. The HSS motor acts
A: FORWORD REVERSE signal on the planetary gear mechanism of the bevel
B: STEERING signal gear shaft to make a difference in speed
C: Engine control information between both sprockets. As a result, the
D: Work equipment pressure signal machine turns.
E: CAN communication network q The power train controller senses the engine
speed and oil pressure at each part and con-
trols the hydraulic, HSS pump and control
valve to drive the hydraulic, HSS pump so that
the engine will not stall.
q The engine speed signal and other engine
control information items are sent and received
through the CAN communication network
which connects the engine throttle controller
and power train controller.
D155AX-6 3
--- Page 11 ---
SEN00605-03 10 Structure, function and maintenance standard
2) Action for the direction of maximizing the pump delivery
37
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q When the difference between pump discharge q The pressure at the large piston diameter end
pressure (PP) and LS pressure (PLS), in other of servo piston (10) becomes drain pressure
words, LS differential pressure ( PLS) (PT), and pump discharge pressure (PP)
becomes smaller [for example, when the area always enters the small diameter end port (J),
of opening of the control valve becomes larger so servo piston (10) is pushed to the left, and
and pump discharge pressure (PP) drops], moves the swash plate in the direction to make
spool (6) is pushed to the left by the combined the delivery larger.
force of LS pressure (PLS) and the force of
spring (4).
q When spool (6) moves, port (D) and port (E)
are interconnected and connected to the PC
valve.
q The PC valve is connected to the drain port, so
the pressure across circuits (D) and (K)
becomes drain pressure (PT). (The operation
of the PC valve is explained later.)
22 D155AX-6
--- Page 12 ---
10 Structure, function and maintenance standard SEN00605-03
A: To transmission case
B: From scavenging pump, steering lubrication pump
C: R.H. brake oil pressure pickup port (RB)
D: L.H. brake oil pressure pickup port (LB)
E: From the pin puller solenoid valve (Drain)
D155AX-6 41
--- Page 13 ---
SEN00605-03 10 Structure, function and maintenance standard
Brake operation
When the brake is βreleasedβ When the brake is βappliedβ
* *
q When the PCCS lever is in the βneutralβ posi- q If the brake pedal is depressed, the brake
tion and the brake pedal is released, the maxi- pressure applied to the back of brake piston (1)
mum brake pressure is applied to the back of starts to lower by the brake control valve.
brake piston (1) by the brake control valve. q At this time, brake piston (1) is pushed back to
q As the oil pressure rises, brake piston (1) com- the right by the tension of the brake spring (2)
presses brake spring (2) and moves to the left to press discs (3) and plates (4) against brake
to eliminate the pressing force between discs drum (5).Brake drum (5) is fixed to the steering
(3) and plates (4). case.
q The power transmitted from bevel gear shaft q Power towards brake hub (6) or output shaft
through HSS to brake hub (6) is transmitted to (7) is controlled by compressing disc (3) and
output shaft (7), then to the final drive. plate (4).
q The brake force can be adjusted by controlling
the oil pressure applied to the back side of
brake piston (1) according to the stroke of the
brake pedal.
60 D155AX-6
--- Page 14 ---
10 Structure, function and maintenance standard SEN00605-03
Sprocket tooth shape of full scale
D155AX-6 79
--- Page 15 ---
SEN00606-01 10 Structure, function and maintenance standard
Main frame 1
18 D155AX-6
--- Page 16 ---
10 Structure, function and maintenance standard SEN00607-06
Accumulator 1 Function
q The accumulator is installed between the
For EPC valve redusing valve and the EPC valve. Even if the
engine is started with the work equipment still
raised, the pressure of the nitrogen gas com-
pressed inside the accumulator sends the pilot
pressure to the control valve to actuate it and
enable the work equipment to move down
under its own weight.
Operation
q After the engine is stopped, when the EPC
valve is at neutral, chamber (A) inside the blad-
der is compressed by the oil pressure in cham-
ber (B).
q When the EPC valve is operated, the oil pres-
sure in chamber (B) goes below 2.9 MPa {30
kg/cm2}, and the pressure of the nitrogen gas
in chamber (A) expands the bladder, so the oil
in chamber (B) acts as the pilot pressure and
actuates the main control valve.
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1. Gas plug
2. Shell *
3. Poppet
4. Holder
5. Bladder
6. Oil port
Specifications
Type of gas: Nitrogen
Gas volume: 500 cc
Max. actuation pressure: 6.86 MPa {70 kg/cm2}
Min. actuation pressure: 0.69 MPa {7 kg/cm2}
D155AX-6 15
--- Page 17 ---
SEN00607-06 10 Structure, function and maintenance standard
1. EPC valve
2. Suction valve
3. LS bypass valve
Unit: mm
No. Check item Criteria Remedy
Standard size Repair limit
Free length
Installation Installation Free Installation
x outer Replace spring if
length load length load
4 Suction valve spring diameter damaged or
5.49 N 4.41 N deformed.
46.8 x 7.5 40.6 β
{0.56 kg} {0.45 kg}
34 D155AX-6
--- Page 18 ---
10 Structure, function and maintenance standard SEN00607-06
Function When pump swash plate does not reach maxi-
q The steering valve is equipped with steering mum angle
priority valve spool (3), so if the steering valve q When the maximum oil flow from the pump is
and the downstream work equipment valve are greater than the sum of the flow demanded by
operated at the same time, priority is given to the steering valve and work equipment valve,
the flow of oil to the steering valve, and the rest an amount of oil that matches the opening of
of the oil discharged from the pump goes to the steering spool (1) flows to the steering valve.
work equipment valve. q An amount of oil decided by the pump dis-
charge pressure, the load pressure and the
Operation area of the spool opening, flows to the work
q When steering spool (1) is operated by EPC equipment valve.
valve output pressure (PI) and the oil flows, a
differential pressure is created between cham- When pump swash plate is at maximum angle
bers (C) and (D). q When the maximum flow of oil from the pump
q Steering priority valve spool (3) is controlled by is smaller than the sum of the oil flow
this differential pressure, and at the same time, demanded by the steering valve and work
the pump swash plate angle is controlled at equipment valve.
PLS = 2.0 MPa {20 kg/cm2}, and the flow of
oil to the steering valve is fixed. 1) When steering valve load Z work equipment
q For details, see β1. Steering valveβ of βControl valve load.
of oil flow.β q An amount of oil that matches the opening of
q In this condition, if downstream work equip- steering spool (1) flows to the steering valve,
ment blade lift spool (2) is operated, the pump and the remaining oil flows to work equipment
discharge pressure momentarily drops. valve.
q At this point, the differential pressure between
chambers (C) and (D) becomes smaller, and 2) When steering valve load > work equipment
steering priority valve spool (3) is moved to the valve load.
left by the pressure in chamber (E) in the direc- q Pump discharge pressure (P) is determined by
tion to throttle the opening to the work equip- the steering valve load, but in this condition, if
ment valve. the downstream work equipment valve where
q At the same time, PLS becomes smaller, so the load is smaller is operated, the difference
the pump swash plate angle moves in the max- in pressure will cause the oil to try to flow to the
imum direction to supply an oil flow to make up work equipment valve, so the pump discharge
the amount that the pressures drops. pressure will drop.
q Steering priority valve spool (3) increases the
size of the opening to the steering system,
while at the same time reducing the size of the
opening to the work equipment in order to
ensure the flow of oil to the steering system.
q In this condition, the flow of oil is divided in pro-
portion to the difference in pressure between
differential pressure (P) β (P1) and differential
pressure (P) β (P2).
The bigger (P1) β (P2) is, the smaller the flow of oil
to the steering system becomes.
D155AX-6 53
--- Page 19 ---
SEN00607-06 10 Structure, function and maintenance standard
At raise of load pressure (P2)
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q When load pressure (P2) rises due to digging q Therefore, differential pressure occurs around
or other operations, pump delivery increases hole (a) in spool (8) and spool (8) moves from
and (P1) pressure rises. Then the expression port (P1) in the direction to close (PR) opening.
{(P1) pressure > Spring (3) force + [area d x Then (P1) pressure is reduced and adjusted to
(PR) pressure]} will hold, and valve (2) will a certain pressure [set pressure] with the