PDF Shop Manual Komatsu PC400LC-6 EXCEL Hydraulic Excavator - 4 MB
The official shop manual for the Komatsu PC400LC-6 EXCEL Hydraulic Excavator provides comprehensive service and repair information.
It is designed for experienced technicians, offering detailed instructions on testing, adjusting, disassembly, and assembly of all machine components.
With this manual, you can diagnose complex issues and perform repairs to factory specifications.
It is the most critical tool for maintaining the performance and reliability of your Komatsu excavator.
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--- Page 1 ---
SEBM037200
1
(PIPE UNDERSIDE SOIL EXCAVATION MACHINE)
EXCEL
MACHINE MODEL SERIAL NUMBER
PC400LC-6 EXCEL 32933 and up
• This shop manual may contain attachments and optional equipment that are not available
in your area. Please consult your local Komatsu distributor for those items you may
require. Materials and specifications are subject to change without notice.
• PC400LC-6 EXCEL mount the SA6D125-2 engine.
For details of the engine, see the 125-2 Series Engine Shop Manual.
© 2004 1 00-1
All Rights Reserved
Printed in Japan 09-04(01)
--- Page 3 ---
FOREWORD COATING MATERIALS
Category Komatsu code Part No. Q'ty Container Main applications, featuresr
• Used as lubricant for sliding portion
LM-G 09940-00051 60 g Can (to prevent from squeaking).
Molybdenum • Used to prevent seizure or scuffling
disulphide of the thread when press fitting or
lubricant LM-P 09940-00040 200 g Tube shrink fitting.
• Used as lubricant for linkage, bear-
ings, etc.
SYG2-400LI • General purpose type
SYG2-350LI
G2-LI SYG2-400LI-A Various Various
SYG2-160LI
SYGA-160CNLI
SYG2-400CA • Used for normal temperature, light
SYG2-350CA load bearing at places in contact
G2-CA SYG2-400CA-A Various Various with water or steam.
SYG2-160CA
SYGA-160CNCA
Molybdenum • Used for heavy load portion
SYG2-400M 400 g × 10 Bellows type
disulphide
Grease SYG2-400M-A 400 g × 20 Bellows type
grease SYGA-16CNM 16 kg Can
LM-G (G2-M)
• Seizure resistance and heat resist-
Hyper White
Grease G2-T SYG2-400T-A ance higher than molybdenum di-
SYG2-16CNT 400 g Bellows type sulfide grease
G0-T (*) SYG0-400T-A (*) 16 kg Can • Since this grease is white, it does
*: For use in cold SYG0-16CNT (*) not stand out against machine
district
body.
Biogrease G2B • Since this grease is decomposed
SYG2-400B by bacteria in short period, it has
G2-BT (*) SYGA-16CNB 400 g Bellows type less effects on microorganisms,
*: For high SYG2-400BT (*) 16 kg Can animals, and plants.
temperature SYGA-16CNBT (*)
and large load
SUNSTAR • Used as primer for cab side
Glass (Using limit: 4 months)
PAINT PRIMER 20 ml container
580 SUPER
Primer
SUNSTAR • Used as primer for glass side
Glass (Using limit: 4 months)
GLASS PRIMER 20 ml container
580 SUPER 417-926-3910
Adhesive for cab glass
• "S" is used for high-tempera-
SUNSTAR ture season (April - October)
PENGUINE Polyethylene and "W" for low-temperature
SEAL 580 320 ml container season (November - April) as
SUPER "S" or
Adhesive adhesive for glass.
"W" (Using limit: 4 months)
Sika Japan, Polyethylene • Used as adhesive for glass.
20Y-54-39850 310 ml (Using limit: 6 months)
Sikaflex 256HV container
SUNSTAR • Used to seal joints of glass
Polyethylene parts.
PENGUINE 417-926-3920 320 ml container (Using limit: 4 months)
SEAL No. 2505
Caulking
material • Used to seal front window.
SEKISUI Polyethylene (Using limit: 6 months)
SILICONE 20Y-54-55130 333 ml container
SEALANT
00-11
--- Page 4 ---
FOREWORD CONVERSION TABLE
Temperature
Fahrenheit-Centigrade Conversion ; a simple way to convert a Fahrenheit temperature reading into a Cen-
tigrade temperature reading or vice versa is to enter the accompanying table in the center or boldface col-
umn of figures.
These figures refer to the temperature in either Fahrenheit or Centigrade degrees.
If it is desired to convert from Fahrenheit to Centigrade degrees, consider the center column as a table of
Fahrenheit temperatures and read the corresponding Centigrade temperature in the column at the left.
If it is desired to convert from Centigrade to Fahrenheit degrees, consider the center column as a table of
Centigrade values, and read the corresponding Fahrenheit temperature on the right.
1°C = 33.8°F
°C °F °C °F °C °F °C °F
–40.4 –40 –40.0 –11.7 11 51.8 7.8 46 114.8 27.2 81 117.8
–37.2 –35 –31.0 –11.1 12 53.6 8.3 47 116.6 27.8 82 179.6
–34.4 –30 –22.0 –10.6 13 55.4 8.9 48 118.4 28.3 83 181.4
–31.7 –25 –13.0 –10.0 14 57.2 9.4 49 120.2 28.9 84 183.2
–28.9 –20 –4.0 –9.4 15 59.0 10.0 50 122.0 29.4 85 185.0
–28.3 –19 –2.2 –8.9 16 60.8 10.6 51 123.8 30.0 86 186.8
–27.8 –18 –0.4 –8.3 17 62.6 11.1 52 125.6 30.6 87 188.6
–27.2 –17 1.4 –7.8 18 64.4 11.7 53 127.4 31.1 88 190.4
–26.7 –16 3.2 –7.2 19 66.2 12.2 54 129.2 31.7 89 192.2
–26.1 –15 5.0 –6.7 20 68.0 12.8 55 131.0 32.2 90 194.0
–25.6 –14 6.8 –6.1 21 69.8 13.3 56 132.8 32.8 91 195.8
–25.0 –13 8.6 –5.6 22 71.6 13.9 57 134.6 33.3 92 197.6
–24.4 –12 10.4 –5.0 23 73.4 14.4 58 136.4 33.9 93 199.4
–23.9 –11 12.2 –4.4 24 75.2 15.0 59 138.2 34.4 94 201.2
–23.3 –10 14.0 –3.9 25 77.0 15.6 0 140.0 35.0 95 203.0
–22.8 –9 15.8 –3.3 26 78.8 16.1 61 141.8 35.6 96 204.8
–22.2 –8 17.6 –2.8 27 80.6 16.7 62 143.6 36.1 97 206.6
–21.7 –7 19.4 –2.2 28 82.4 17.2 63 145.4 36.7 98 208.4
–21.1 –6 21.2 –1.7 29 84.2 17.8 64 147.2 37.2 99 210.2
–20.6 –5 23.0 –1.1 30 86.0 18.3 65 149.0 37.8 100 212.0
–20.0 –4 24.8 –0.6 31 87.8 18.9 66 150.8 40.6 105 221.0
–19.4 –3 26.6 0 32 89.6 19.4 67 152.6 43.3 110 230.0
–18.9 –2 28.4 0.6 33 91.4 20.0 68 154.4 46.1 115 239.0
–18.3 –1 30.2 1.1 34 93.2 20.6 69 156.2 48.9 120 248.0
–17.8 0 32.0 1.7 35 95.0 21.1 70 158.0 51.7 125 257.0
–17.2 1 33.8 2.2 36 96.8 21.7 71 159.8 54.4 130 266.0
–16.7 2 35.6 2.8 37 98.6 22.2 72 161.6 57.2 135 275.0
–16.1 3 37.4 3.3 38 100.4 22.8 73 163.4 60.0 140 284.0
–15.6 4 39.2 3.9 39 102.2 23.3 74 165.2 62.7 145 293.0
–15.0 5 41.0 4.4 40 104.0 23.9 75 167.0 65.6 150 302.0
–14.4 6 42.8 5.0 41 105.8 24.4 76 168.8 68.3 155 311.0
–13.9 7 44.6 5.6 42 107.6 25.0 77 170.6 71.1 160 320.0
–13.3 8 46.4 6.1 43 109.4 25.6 78 172.4 73.9 165 329.0
–12.8 9 48.2 6.7 44 111.2 26.1 79 174.2 76.7 170 338.0
–12.2 10 50.0 7.2 45 113.0 26.7 80 176.0 79.4 175 347.0
00-21
--- Page 5 ---
10 STRUCTURE AND FUNCTION
Parts related to engine .............................. 10- 2
Radiator, oil cooler ..................................... 10- 4
Engine control ............................................ 10- 5
Power train ................................................. 10- 6
Final drive ................................................... 10- 7
Swing circle ................................................ 10- 8
Swing machinery ....................................... 10- 9
Track frame, recoil spring ......................... 10- 10
Track shoe ................................................... 10- 11
Hydraulic piping drawing .......................... 10- 12
Hydraulic circuit diagram .......................... 10- 14
Hydraulic tank, hydraulic filter .................. 10- 15
Hydraulic pump .......................................... 10- 17
Control valve .............................................. 10- 34
Self-reducing pressure valve .................... 10- 43
Suction safety valve ................................... 10- 48
CLSS ............................................................ 10- 49
Swing motor ............................................... 10-112
Center swivel joint ..................................... 10-116
Travel motor ............................................... 10-118
Valve control ............................................... 10-127
Work equipment • swing PPC valve ........ 10-128
Travel PPC valve ........................................ 10-132
Service PPC valve ...................................... 10-136
PPC accumulator ........................................ 10-139
PPC shuttle valve, travel junction valve ... 10-141
Solenoid valve ............................................ 10-148
Boom holding valve ................................... 10-150
Work equipment ......................................... 10-154
Air conditioner ............................................ 10-155
Actual electric wiring diagram .................. 10-156
Electric circuit diagram .............................. 10-160
Electric control system .............................. 10-163
Machine monitor system ........................... 10-169
PC400-6 EXCEL 10-1
--- Page 6 ---
STRUCTURE AND FUNCTION TRACK SHOE
TRACK SHOE
Standard shoe
Model
PC400-6 EXCEL PC400LC-6 EXCEL
Item
Shoe width (mm)
600 600
(triple shoe)
Link pitch (mm) 228.6 228.6
No. of shoes
46 49
(each side)
Selection of track shoe
• Select the most suitable track shoe from the following table
PC400-6 EXCEL PC400LC-6 EXCEL
Specifications gory Specifications Cate-
Cate-
gory
Standard 600 mm triple A 600 mm triple A
Option 700 mm triple B 700 mm triple B
Option 800 mm triple B 800 mm triple B
Category Use Precautions when using
Rocky ground, • Travel in Lo speed when traveling on rough ground with
A
normal river soil obstacles such as large boulders and fallen trees.
• Cannot be used on rough ground where there are large
obstacles such as boulders and fallen trees.
B Normal soil, soft land • Travel in Hi speed only on flat ground; when it is impossible
to avoid traveling over obstacles, lower the travel speed
to approx. half of Lo speed.
• Use only for ground where “A” and “B” sink and are impossible
to use.
• Cannot be used on rough ground where there are large
Extremely soft ground
C obstacles such as boulders and fallen trees
(swampy ground)
• Travel in Hi speed only on flat ground; when it is impossible
to avoid traveling over obstacles, lower the travel speed
to approx. half of Lo speed.
D Paved surface • The shoes are flat, so they have low gradeability
• The shoes are made of rubber, so be careful when traveling
E Paved surface
on rough ground
fl Categories “B” and “C” are wide shoes, so fl When selecting the shoe width, select the
there are restrictions on their use. There- narrowest shoe possible within the range
fore, before using, check the restrictions and that will give no problem with flotation and
consider carefully the conditions of use be- ground pressure.
fore recommending a suitable shoe width. If If a wider shoe than necessary is used, there
necessary, give the customer guidance in will be a large load on the shoe, and this
their use. may lead to bending of the shoe, cracking of
the links, breakage of the pins, loosening of
the shoe bolts, or other problems.
PC400-6 EXCEL 10-11
--- Page 7 ---
STRUCTURE AND FUNCTION HYDRAULIC PUMP
2. Control of discharge amount
2 4
12 15
SAP00167
• If swash plate angle α becomes larger, the • With servo piston (12), the area receiving
difference in volumes E and F becomes larger the pressure is different on the left and right,
and discharge volume Q increases. so main pump discharge pressure (self pres-
• Swash plate angle α is changed by servo sure) PP is always connected to the cham-
piston (12). ber receiving the pressure on the small di-
• Servo piston (12) moves in a reciprocal ameter piston side (the self-pressure is
movement (↔) according to the command brought in). Output pressure Pen of the LS
from the control valve. valve is brought to the chamber receiving
• This straight line movement is transmitted the pressure at the large diameter piston
through rod (15) to rocker cam (4), and rocker end. The relationship in the size of self-pres-
cam (4), which is supported by the cylindri- sure PP and the pressure at the small diam-
cal surface to cradle (2), moves in a rocking eter piston end, and the ratio between the
movement on the cylindrical surface in area receiving the pressure at the small di-
↔
( direction). ameter piston end and the large diameter
piston end controls the movement of servo
piston (12).
PC400-6 EXCEL 10-21
--- Page 8 ---
STRUCTURE AND FUNCTION HYDRAULIC PUMP
5
10
3
4
6
7
SBP00178
2) When load on actuator is small and pump
discharge pressure is high
• When the load is large and pump discharge • If main pump pressures Pa1 and Pa2 increase
pressures Pa1 and Pa2 are high, the force further and piston (2) moves further to the
pushing piston (2) to the left becomes larger left, main pump pressure Pa1 flows to port c
and piston (2) moves to the position shown and acts to make the discharge amount the
in the diagram above. When this happens, minimum. When piston (9) moves to the left,
as shown in the diagram above, with the piston (5) is moved to the right by cam (7)
pressurized oil flowing from port c to the LS and lever (6). For this reason, springs (3)
valve, part of the pressurized oil from port b and (4) are compressed and push back pis-
flows out to port d and becomes approxi- ton (2). Because of this force, piston (2) cuts
mately 2/5 of main pump pressure Pa1. off the connection from port b to port c, and
• When port h and port e of the LS valve are port c and port d are connected. As a result,
connected (see 1. LS valve), the pressure the pressure at port c (= f) drops, and piston
from port f enters the large piston diameter (9) stops moving to the left. The position in
end of servo piston (9), and servo piston (9) which piston (9) stops when this happens is
stops. further to the left than the position when
main pump pressures Pa1 and Pa2 are low.
PC400-6 EXCEL 10-31
--- Page 9 ---
STRUCTURE AND FUNCTION SELF-REDUCING PRESSURE VALVE
SELF-REDUCING PRESSURE VALVE
P1 : From front pump
T : To hydraulic tank
PC : —
PR : Supply to electromagnetic valve,
PPC valve, solenoid valve
PC400-6 EXCEL 10-43
--- Page 10 ---
STRUCTURE AND FUNCTION CLSS
1A. Main relief valve (bucket group)
Set pressure: 34.8 ± 0.5 MPa {355 ± 5 kg/cm2}
1B. Main relief valve (arm group)
Set pressure: 34.8 ± 0.5 MPa {355 ± 5 kg/cm2}
2A. Unload valve (bucket group)
Clutch pressure: 2.9 ± 0.2 MPa {30 ± 2 kg/cm2}
2B. Unload valve (arm group)
Clutch pressure: 2.9 ± 0.2 MPa {30 ± 2 kg/cm2}
3. Pressure compensation valve
4A. Safety-suction valve
Set pressure: 28.4 ± 0.5 MPa {290 ± 5 kg/cm2}
4B. Safety-suction valve
Set pressure: 35.8 ± 0.5 MPa {365 ± 5 kg/cm2}
5. Safety-suction valve (for large flow)
Set pressure: 35.8 ± 0.5 MPa {365 ± 5 kg/cm2}
6. Bucket spool
7. LS shuttle valve
8. R.H. travel spool
9. Suction valve
10. Boom Lo spool
11. Check valve (for boom regeneration circuit)
12. Swing spool
13. L.H. travel spool
14. Arm Lo spool
15. Check valve (for arm regeneration circuit)
16. Boom Hi spool
17. Arm Hi spool
18. LS select valve
19. Merge/flow divider valve
PC400-6 EXCEL 10-53
--- Page 11 ---
STRUCTURE AND FUNCTION CLSS
2 A 4 B
1
SLP00215
< For travel>
• No holding pressure is generated at port A
in the travel circuit, so a pressure compen-
sation valve without a shuttle valve is used.
SBP00216
Reference: When there is no shuttle valve
• If there is no shuttle valve, piston (4) and LS pressure
valve (2) will separate. In this condition, if Time lag
another actuator is operated, the piston acts
as an accumulator, so there is a time lag.
Holding pressure
Time
SAP00217
PC400-6 EXCEL 10-63
--- Page 12 ---
STRUCTURE AND FUNCTION CLSS
PC400-6 EXCEL 10-73
--- Page 13 ---
STRUCTURE AND FUNCTION CLSS
Operation (When pump flow merged, arm IN
operated independently)
• When the arm IN is operated, unload valves
(29A, 29B) are closed.
• The swash plate of the main pump is con-
trolled (LS control) to match the total area of
the meter-in opening of arm Lo spool (11)
and arm Hi spool (13).
(∆PLS = pump LS control pressure)
• When the spool meter-in opening comes
near the maximum, both pumps are at the
maximum swash plate angle.
(When the pump discharge is the maximum,
the maximum area of opening of the spool
is also large, so the LS differential pressure
is smaller than the LS control pressure and
the swash plate angle is always at the maxi-
mum.)
(∆PLS < pump LS control pressure)
10-86 PC400-6 EXCEL
--- Page 14 ---
STRUCTURE AND FUNCTION CLSS
When pump flow merged, swing + boom RAISE operated simultaneously
Connection of ports when pump flow is merged
Connected ports: A – D, B – C
10-100 PC400-6 EXCEL
--- Page 15 ---
STRUCTURE AND FUNCTION SWING MOTOR
1. Spring 9. Piston assembly
2. Output shaft 10. Cylinder block
3. Oil seal 11. Spring
4. Case 12. Center shaft
5. Plate 13. Valve plate
6. Disc 14. Suction valve spring
7. Brake piston 15. Suction-safety valve
8. Housing
PC400-6 EXCEL 10-113
--- Page 16 ---
STRUCTURE AND FUNCTION TRAVEL MOTOR
Control valve
Operation of brake valve
• The brake valve consists of a check valve, PA PB
counterbalance valve, and safety valve in a
circuit as shown in the diagram on the right.
Check
(Fig. 1) valve
• The function and operation of each compo-
nent is as given below. Counter-
balance
valve
MA MB
1) Counterbalance valve, check valve
Function
• When traveling downhill, the weight of the Safety
valve
machine makes it try to travel faster than
the speed of the motor.
As a result, if the machine travels with the (Fig. 1)
SAP00262
engine at low speed, the motor will rotate
without load and the machine will run away,
which is extremely dangerous. Control valve
To prevent this, these valves act to make the 18a PA PB 18b
machine travel according to the engine speed
(pump discharge amount).
19
Operation when pressurized oil is supplied
• When the travel lever is operated, the pres-
surized oil from the control valve is supplied
to port PA. It pushes open check valve (18a)
and flows from motor inlet port MA to mo-
tor outlet port MB. MA MB
However, the motor outlet port is closed by
check valve (18b) and spool (19), so the pres-
sure at the supply side rises. (Fig. 2). (Fig. 2)
• The pressurized oil at the supply side flows SAP00263
from orifice E1 in spool (19) and orifice E2 in
the piston to chamber S1. When the pres-
sure in chamber S1 goes above the spool Control valve
switching pressure, spool (19) is pushed to
the right. As a result, port MB and port PB 18a PA PB 18b
are connected, the outlet port side of the
motor is opened, and the motor starts to E1 19
rotate. (Fig. 3).
S1 MA MB
E2
(Fig. 3)
SAP00264
PC400-6 EXCEL 10-123
--- Page 17 ---
STRUCTURE AND FUNCTION TRAVEL PPC VALVE
1. Plate 5. Metering spring
2. Body 6. Centering spring
3. Piston 7. Valve
4. Collar 8. Bolt
PC400-6 EXCEL 10-133
--- Page 18 ---
STRUCTURE AND FUNCTION PPC SHUTTLE VALVE, TRAVEL JUNCTION VALVE
1. Body
2. Plug
3. Ball
10-144 PC400-6 EXCEL
--- Page 19 ---
STRUCTURE AND FUNCTION AIR CONDITIONER
AIR CONDITIONER
AIR CONDITIONER PIPING
1. Hot water pickup piping A : Fresh air
2. Air conditioner compressor B : Recirculated air
3. Refrigerant piping C : Hot air/cold air
4. Condenser
5. Receiver tank
6. Hot water return piping
7. Air conditioner unit
8. Duct
PC400-6 EXCEL 10-155
--- Page 20 ---
STRUCTURE AND FUNCTION ELECTRIC CONTROL SYSTEM
Function
• The pump controller sets the pump absorp-
tion torque to match the engine speed.
• When the engine is running at high speed, it
raises the pump absorption torque to boost
the productivity. When the engine is run-
ning at low speed, it throttles the pump ab-
sorption torque to prevent the engine from
stalling.
PC400-6 EXCEL 10-165
--- Page 21 ---
TESTING AND ADJUSTING STANDARD VALUE TABLE FOR ENGINE RELATED PARTS
STANDARD VALUE TABLE FOR ENGINE RELATED PARTS
Applicable model PC400, 400LC-6 EXCEL
Engine SA6D125E-2
Item Measurement conditions Unit Standard value Service limit value
for new machine
High idling 2,150 ± 70 2,150 ± 50
+90 +90
Engine speed Low idling rpm 700 –10 850 –10
Rated speed 1,950 —
Air supply pressure At rated speed kPa Min. 107 Min. 107
(boost pressure) {mmHg} {Min. 800} {Min. 800}
At sudden acceleration Bosch Max. 5.5 7.5
Exhaust gas color index
At high idling Max. 1.0 2.0
Valve clearance Intake valve 0.33 —
(normal temperaure) mm
Exhaust valve 0.71 —
Oil temperature: