PDF Shop Manual Komatsu PC700LC-8E0 Hydraulic Excavator - 9 MB
Unlock the full potential of your heavy machinery with the official shop manual for the Komatsu PC700LC-8E0 Hydraulic Excavator.
This document is meticulously detailed, offering factory-approved procedures for diagnostics, repairs, and assembly.
It is the definitive guide for technicians needing to service the complex hydraulic and electrical systems.
Using this manual is the best way to reduce downtime and maintain your excavator's powerful performance.
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--- Page 1 ---
UEN05377-00
HYDRAULIC
EXCAVATOR
PC700LC-8E0
SERIAL NUMBERS PC700LC-8E0 K50001 and up
--- Page 3 ---
Table of Contents
Troubleshooting with gauge pressure.................................................................................. 75
Connection of service tool ................................................................................................... 78
Precautions for disconnecting and connecting air conditioner piping .................................. 80
Handling of compressor oil .................................................................................................. 82
90 Diagrams and drawings ........................................................................................................ 1
Hydraulic circuit diagram ........................................................................................................ 3
Symbols used in hydraulic circuit diagrams......................................................................... 3
Hydraulic circuit diagram (1/3) Backhoe specification ......................................................... 7
Hydraulic circuit diagram (2/3) Attachment specification ..................................................... 9
Hydraulic circuit diagram (3/3) Breaker specification for low back pressure ....................... 11
Electrical circuit diagram ......................................................................................................... 13
Symbols used in electric circuit diagrams............................................................................ 13
Air conditioner electrical circuit diagram .............................................................................. 27
PC700LC-8E0 00-11
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Foreword and general information
Method of disconnecting and connecting push-pull type coupler
Method of disconnecting and connecting push-pull type coupler 0 -23
(Rev. 2010/03)
k Before performing the following work, loosen the oil filler cap of the hydraulic tank gradually to
release the remaining pressure in the hydraulic tank.
k Even if the remaining pressure is released from the hydraulic tank, some hydraulic oil flows out
when the hose is disconnected. Accordingly, prepare an oil container.
Type 1 0 -23
1. Disconnection
1) Hold adapter (1) and push hose joint (2) into
mating adapter (3). (Fig. 1)
a The adapter can be pushed in about 3.5
mm.
a Do not hold rubber cap portion (4).
2) With hose joint (2) pushed into adapter (3),
press rubber cap portion (4) against adapter
(3) until it clicks. (Fig. 2)
3) Hold hose adapter (1) or hose (5) and pull it
out. (Fig. 3)
a Since some hydraulic oil flows out, pre-
pare an oil container.
2. Connection
1) Hold hose adapter (1) or hose (5) and insert
it in mating adapter (3), aligning them with
each other. (Fig. 4)
a Do not hold rubber cap portion (4).
2) After inserting the hose fitting in the adapter
on the other side perfectly, pull it back to
check the connecting condition (Fig. 5)
a When the hose is pulled back, the rubber
cap portion moves toward the hose about
3.5 mm. This does not indicate abnormal-
ity, however.
PC700LC-8E0 00-23
--- Page 5 ---
Foreword and general information
Handling of electric equipment
5. Handling controller
1) The controller contains a microcomputer and
electronic control circuits. These control all of
the electronic circuits on the machine, so be
extremely careful when handling the
controller.
2) Do not place objects on top of the controller.
3) Cover the control connectors with tape or a
vinyl bag. Never touch the connector
contacts with your hand.
4) During rainy weather, do not leave the
controller in a place where it is exposed to
rain.
5) Do not place the controller on oil, water, or
soil, or in a place that can be heated to a high
temperature even for a short time. (Place it
on a suitable dry stand.)
6) Precautions when performing arc welding
When performing arc welding on the
machine body, disconnect all of the wiring
harness connectors connected to the
controller. Fit an arc welding ground to the
place close to the welding point.
6. Points to remember when troubleshooting
electric circuits
1) Be sure to turn the power OFF before discon-
necting or connecting connectors.
2) Before performing troubleshooting, check all
the related connectors for loose connection.
a Disconnect and connect the related con-
nectors several times to check.
3) Be sure to connect any disconnected
connectors before going on to the next step.
a If the power is turned ON with the connec-
tors still disconnected, unnecessary
warning will be displayed.
4) When performing troubleshooting of circuits
(measuring the voltage, resistance, conti-
nuity, or current), wag the related wiring
harnesses and connectors several times and
check that there is no change in the reading
of the tester.
a If there is any change, there may be de-
fective contact in the circuit.
PC700LC-8E0 00-35
--- Page 6 ---
Foreword and general information
List of abbreviation
Purpose of use (major appli-
Abbrevia-
Full Spelling cable machine (*), or compo- Explanation
tion
nent/system)
System that allows data (filter, oil replacement
Equipment Management interval, malfunctions on machine, failure code,
E.M.M.S. Machine monitor
Monitoring System and failure history) from each sensor on the
machine to be checked on monitor.
Control system that moves an actuator in propor-
Electromagnetic Propor-
E.P.C. Hydraulic tion to the amperage of an electric current passing
tional Control
through the solenoid.
F-N-R Forward-Neutral-Reverse Operation Position of the gear shift lever or switch.
System that is used to determine the current loca-
Global Positioning Sys- Communication tion on the Earth of a ship, car, machine, etc. by
G.P.S.
tem (KOMTRAX, VHMS) receiving the radio wave signals transmitted from
the navigation satellites.
Steering function that uses a combination of
Hydrostatic Steering Sys- Steering hydraulic motor and bevel shaft to control differ-
H.S.S.
tem (D) ence in travel speed of right and left tracks to turn
machine without using steering clutch.
Hydraulic transmission system that uses a combi-
Hydro Static Transmis- Transmission
H.S.T. nation of hydraulic pump and hydraulic motor to
sion (D, WA)
shift gear steplessly without using gears.
Valve installed at inlet port of pump to adjust fuel
I.M.A. Inlet Metering Actuator Engine intake amount in order to control fuel discharge
amount of supply pump. Same as IMV.
Valve installed at inlet port of pump to adjust fuel
I.M.V. Inlet Metering Valve Engine intake amount in order to control fuel discharge
amount of supply pump. Described as IMV (IMA).
Image display device made up of a large number of
L.C.D. Liquid Crystal Display Machine monitor
pixels filled with liquid crystal.
Semiconductor element that emits light when the
L.E.D. Light Emitting Diode Electronic parts voltage is applied in forward direction, positive volt-
age to anode and negative voltage to cathode.
Function that senses differential pressure of pump
L.S. Load Sensing Hydraulic
and controls discharge amount according to load.
Service that allows transmission and reception of
Multimedia Messaging
M.M.S. Communication short messages consisting of characters or voice
Service
or images between cell phones.
Device actuated to open electric or hydraulic cir-
N.C. Normally Closed Electric and hydraulic
cuits that are normally closed if not actuated.
Device actuated to close electric or hydraulic cir-
N.O. Normally Open Electric and hydraulic
cuits that are normally open if not actuated.
Open-center Load Sens- Hydraulic system that can operate multiple actua-
O.L.S.S. Hydraulic
ing System tors at the same time, regardless of the load.
P.C. Pressure Control Hydraulic Controlling the oil pressure.
System in which a controller instantly analyses
Palm Command Control Steering data from each lever, pedal, and dial, and performs
P.C.C.S.
System (D) optimum electronic control of the engine and trans-
mission.
Valve installed at inlet port of pump to adjust fuel
P.C.V. Pump Control Valve Engine intake amount in order to control fuel discharge
amount of supply pump.
Proportional Pressure Control system that moves an actuator in propor-
P.P.C. Hydraulic
Control tion to the oil pressure.
Hydraulic
P.P.M. Piston Pump and Motor Piston pump and motor.
(D, PC, etc.)
P.T.O. Power Take Off Power transmission A device to take off power of the engine.
Power Tilt and power Work equipment Function that performs hydraulic control of the tilt
P.T.P.
Pitch dozer (D) and pitch of the bulldozer blade.
PC700LC-8E0 00-47
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Specifications
Working range drawings
Working range drawings
Backhoe specification 01-5
Item Unit PC700LC-8E0
A Max. digging reach mm 12,640
B Max. digging depth mm 8,010
C Max. digging height mm 11,680
D Max. vertical wall digging depth mm 6,480
E Max. dumping height mm 7,810
F Max. reach at ground level mm 12,380
PC700LC-8E0 01-5
--- Page 8 ---
Power train system
Power train
1. Idler 7. Engine 14. Swing machinery
2. Centre swivel joint 8. PTO 15. Swing circle
3. Swing motor (KMF90ABE-3) 9. No. 2 pump (HPV95+95) 16. Travel speed solenoid valve
4. Control valve 10. Fan pump (LPV75) 17. Swing holding brake solenoid valve
5. Final drive and sprocket 11. Control pump (SAL56)
6. Travel motor 12. PTO lubrication pump A. Control valve
PC700 (MSF-340VP-FH9) 13. No. 1 pump (HPV95+95) B. Swing brake solenoid valve
PC700LC-8E0 10-7
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Hydraulic system
Hydraulic tank and filter
1. Hydraulic oil filter
1A. Bypass valve
1B. Strainer
1C. Element
1D. Cooler check valve
2. Hydraulic tank
3. Suction strainer
4. Sight gauge
5. Oil filler port cap
6. Breather
Specifications 10-21
Tank capacity: 500 l
Hydraulic oil level in tank: 380 l (at level H)
Cap 10-21
q Relief cracking pressure:
16.7 ± 6.9 kPa {0.17 ± 0.07 kg/cm2}
q Suction valve operating pressure:
0 – 0.49 kPa {0 – 0.005 kg/cm2}
q Bypass valve set pressure:
0.15 ± 0.03 MPa {1.5 ± 0.3 kg/cm2}
Breather 10-21
q Suction valve operating pressure:
0 – 2 kPa {0 – 0.02 kg/cm2}
q Relief cracking pressure:
0.1 ± 0.015 MPa {1.0 ± 0.15 kg/cm2}
PC700LC-8E0 10-19
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Hydraulic system
Hydraulic pump (piston pump)
Function 10-3
q When the power mode is set in the P-mode or q When the emergency pump drive switch is in ON
E-mode, the pump delivery is optimally control- position, the pump delivery is controlled by sens-
led with the command current sent from the con- ing the pump delivery pressure (load) to keep the
troller according to the engine speed. pump absorption torque at a constant level.
1) When command current value from controller is small in P and E mode 10-3
Operation 10-3
q The command current sent from the controller q As a result, the opening between ports (a) and
actuates solenoid push pin (9) and spool (2) (b) are opened almost fully and almost all of the
moves. Spool (2) stops at a point where the total pressurized oil from the control pump is output
forces acting on piston (3), that are the force of as TVC valve output pressure (PE). Then, TVC
spring (1), the force of push pin (9) and the force valve output pressure (PE) and signal pressure
exerted by TVC valve output pressure (PE), are (PECN) increase, thus the pump delivery in-
balanced. In this case, the force of push pin (9) creases.
is small because of the small command current,
spool (2) is stopped at the bottom.
PC700LC-8E0 10-31
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Hydraulic system
Hydraulic pump (piston pump)
No.2 main pump 10-45
Model: HPV95+95
PA1: Front pump delivery port 1. Front pump
PA2: Rear pump delivery port 2. Front servo valve
PD12: Drain 3. Rear servo valve
PD22: Drain 4. Rear pump
PS: Pump suction port
PSV: Servo source pressure IN port
PECN: CO+NC valve output pressure port
PC700LC-8E0 10-43
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Hydraulic system
Cooling fan pump
Operation 10-57
q The EPC valve output pressure enters the piston
chamber and presses the piston (6). Piston (6)
moves spool (5) to a position where it is bal-
anced with the spring force.
q Then, the notch in spool (5) connects land (PE)
in the servo piston pressure passage to the
pump delivery pressure passage. Pump delivery
pressure is transmitted to the servo piston.
q The servo piston pushes up the rocker cam.
Then a positioning feedback is applied, and the
lever moves in the direction contracting the
spring.
q When spool (5) is pushed back, the pump dis-
charge pressure passage is disconnected from
the servo piston circuit. The pressure in the ser-
vo piston chamber lowers and the rocker cam re-
turns toward the position for the maximum
swash plate angle.
q These processes are repeated until the swash
plate stabilizes at an angle where the force ex-
erted by the EPC output pressure is balanced
with the spring force.
q Accordingly, as the EPC output pressure in-
creases, the swash plate angle decreases. As
the EPC output pressure lowers, the swash plate
angle increases.
PC700LC-8E0 10-55
--- Page 13 ---
Hydraulic system
Control valve
(4/4)
1. Suction-safety valve 7. Spool (arm Lo)
2. Spool (bucket Lo) 8. Safety valves with suction
3. Spool (arm throttle) 9. Check valve
4. Spool (service / bucket Hi) 10. Spool (R.H. travel)
5. Spool (arm Hi) 11. Suction-safety valve
6. Check valve 12. Suction valve
PC700LC-8E0 10-67
--- Page 14 ---
Hydraulic system
Swing motor
1. Drive shaft 11. Cylinder block
2. Spacer 12. Valve plate
3. Case 13. Piston
4. Disc 14. Centre shaft
5. Plate 15. Safety valve
6. Brake ring 16. Check valve
7. Brake piston 17. Check valve spring
8. Housing 18. Shuttle valve
9. Reversal prevention valve 19. Shuttle valve spring
10. Centre spring 20. Brake spring
PC700LC-8E0 10-79
--- Page 15 ---
Hydraulic system
Travel motor
2) At high-speed setting (automatic Hi/Low speed switching) 10-103
q When the pilot signal is ON, pilot pressure (PI) 1) When travelling on a flat ground and in other
from the control pump acts on speed selector cases where the travel motor's drive pres-
valve (1) and the motor capacity is automatically sure is low, the relationship between these
switched by the drive pressure of the travel mo- forces is F1 > F2, and spool (1a) is pushed to
tor. the right.
At this time, main hydraulic pressures (M1)
Balance of force for travel speed selector valve and (M2) are transmitted through spool (1a)
F1 [force pushing spool (1a) to the right (high-speed to the control piston chamber. Thrust force
side)] (Fc) of control piston (10) lets rocker cam
= A (area of pressure-receiving surface of spool (14) to hydraulically overcome moment (Mx).
(1a)) x PI Rocker cam (14) tilts and is fixed on the
F2 [force pushing spool (1a) to the left (low-speed high-speed surface where the moment is
side)] balanced. (Mx < Fc, L)
= A (area of pressure-receiving surface of spool
(1a)) x PH (motor drive pressure) x force in 2) When steering, travelling uphill, or in other
spring (1b) cases where the travel motor's drive pres-
sure is high and exceeds the set pressure,
the relationship F1 < F2 holds, and spool (1a)
is pushed to the left.
In this situation, main hydraulic pressures
(M1) and (M2) are drained to the motor case
via spool (1a), and in the same way as when
(PI) = 0, the low-speed setting is achieved.
PC700LC-8E0 10-91
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Hydraulic system
PPC valve
1. Plate
2. Case
3. Piston
4. Seal
5. Spool
6. Damper
PC700LC-8E0 10-103
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Hydraulic system
Boom drift prevention valve
2. When the boom is in neutral 10-127
Operation 10-127
q When the control lever is returned to NEUTRAL
with the boom raised, the holding pressure at the
bottom end of the boom cylinder is trapped by
poppet (5). At the same time, the oil flowing into
the valve through orifice (a) of poppet (5) is
trapped by pilot spool (3). As a result, the boom
is held in position.
PC700LC-8E0 10-115
--- Page 18 ---
Hydraulic system
Hydraulic drift prevention valve
3. When returning pressurized oil to the main If the piping is bursted
valve from the work equipment cylinder • If piping (A) bursts between the control valve
and the work equipment cylinder.
When the piping is free of burst • Pressurized oil in chamber (a) flows out to the
• Holding pressure of the work equipment cylin- bursted portion but re supplied from chamber
der is led to chamber (b) and check valve (5) (b).
closes. • Since pressurized oil flows via opening (c) of
• Pilot pressure from the PPC valve is led to port spool (1), a sudden drop of the cylinder is pre-
(PI) and reaches [Pilot Pressure > Force of vented.
Spring (3)] (area of d).
• Spool (1) moves to the right to the standby
position. (1st stage stroke)
• At this point, chambers (a) and (b) are not
interconnected.
• Pilot pressure further rises, and reaches [Pilot
pressure > Force of spring (2)] (area of d).
• Spool (1) moves further to the right, and cham-
bers (a) and (b) are interconnected. (2nd stage
stroke)
• Pressurized oil returns to the control valve
from the work equipment cylinder.
PC700LC-8E0 10-127
--- Page 19 ---
Electrical system
Engine control
EGR valve position sensor and bypass valve position sensor 10-146
q These sensors sense the opening and closing positions of the EGR valve and bypass valve.
1. EGR valve position sensor and bypass valve position sensor
q The following graph shows the output characteristics of the position sensor.
PC700LC-8E0 10-139
--- Page 20 ---
Electrical system
Electrical control system
1) Control in each mode 10-159
P, E and L modes
q Matching point of P, E and L modes: Rated output point
Model
PC700LC-8E0 Cut-off 2-stage relief Relief pressure
P0 1,800 rpm x x
31.9 MPa {325 kg/cm2}
P1 1,800 rpm Q x
E0 1,720 rpm
Mode
E1 1,680 rpm
Q x 31.9 MPa {325 kg/cm2}
E2 1,640 rpm
E3 1,580 rpm
L 1,730 rpm x Q 37.2 MPa {380 kg/cm2}
q When the load on the pump increases and the
pump pressure rises, the engine speed goes
down.
At this time, the pump is controlled to reduce its
delivery so that engine speed recovers close to
the rated output point. If the pump pressure goes
down, the pump is controlled to increase its
delivery so that the engine speed becomes close
to the rated output point.
By repeating this control, the engine can always
be used at near the rated output point.
q Compared with the P mode, which provides the
maximum engine output, the E mode lowers the
engine output to provide the matching point
which gives better fuel efficiency than that of the
P mode.
2) Cut-off function 10-159
q If the load during work increases and the pump
delivery pressure rises to near the relief pres-
sure, the hydraulic pump cut-off valve is actuat-
ed to reduce the relief loss.
PC700LC-8E0 10-151
--- Page 21 ---
Electrical system
Electrical control system
Travel speed selection function 10-171
1. Manual selection with travel speed switch
When one of "Lo" and "Hi" is selected with the
travel speed switch, the pump controller controls
the pump capacity and motor capacity for the
speed setting as shown below to change the
travel speed.
Lo Hi
Travel speed selector switch (low (high
speed) speed)
Motor capacity Max. Min.
Travel speed
PC700LC 2.8 4.6
(km/h)
2. Automatic selection according to engine speed
If the engine speed is set below 1,200 rpm by
using the fuel control dial:
q The travel speed does not switch to Hi setting
when the machine is travelling in Lo setting.
q The travel speed automatically switches to
Lo setting when the machine is travelling in
Hi setting.
3. Automatic selection according to pump delivery
pressure
When the machine is travelling with the travel
speed switch at Hi and the load increases, such
as when travelling up a steep hill, if the travel
pressure continues at 31.4 MPa {320 kg/cm2}
for more than 2.0 seconds, the pump volume is
automatically switched and the travel speed
changes to Lo setting.
(The travel speed switch stays at Hi.)
The machine continues to travel in Lo, and when
the load is reduced, such as when the machine
travels again on flat ground or goes downhill,
and the travel pressure stays at 22.6 MPa
{230 kg/cm2} or less for more than 1.0 second,
the pump volume is automatically switched and
the travel speed returns to Hi setting.
PC700LC-8E0 10-163
--- Page 22 ---
Electrical system
Monitor system
Input/Output signal 10-183
CN-CM01
Input/out- Input/out-
Pin No. Signal name Pin No. Signal name
put put
1 Battery power (+24V unswitched) Input RS232C RTS for communication termi-
6 Output
2 Battery power (+24V unswitched) Input nal
3 Battery power GND – RS232C TXD for communication termi-
7 Output
nal
4 Battery power GND – RS232C DTR for communication termi-
Input/out- 8 Output
5 Wake-up nal
put RS232C DSR for communication termi-
9 Input
6 Relay output Output nal
7 NC (*) – RS232C CTS for communication termi-
10 Input
nal
8 NC (*) –
11 RS232C RI for communication terminal Input
9 Fuel level Input
12 Power GND for communication terminal –
10 NC (*) – Input CH1 for communication terminal
13 Input
11 Battery charge Input status
12 Chassis analog signal GND – Output for communication terminal
14 Output
power control
13 Light (switch) Input Output CH1 for communication terminal
15 Output
14 Key switch (ACC) Input control
15 Key switch (C) Input Output CH2 for communication terminal