The Komatsu PC450LC-8 Crawler Excavator Shop Manual (SEN02223-26) is the workshop book for tearing into this mid-size production excavator, not just changing filters. Guys like dealer techs, independent shop mechanics, and serious owner-operators reach for this when a fault code won’t clear or a major component has to come off the machine. They’re usually trying to chase down hydraulic or electrical problems, rebuild major assemblies, or verify they’re putting things back together the way Komatsu intended.
What this manual helps you do
- Trace hydraulic issues through the main and auxiliary circuits using factory-style diagnostic steps and schematic references.
- Diagnose electrical and electronic faults on the PC450LC-8 using wiring diagrams, connector views, and guided test procedures.
- Follow teardown and reassembly sequences for engine, pumps, final drives, swing machinery, and other major components.
- Check adjustment points for travel, swing, work equipment, and control linkages so the machine runs within Komatsu’s intended settings.
- Handle failure analysis and inspection after breakdowns, so you can decide whether to repair, rebuild, or replace components.
Who this is for
This shop manual is aimed at field techs, shop mechanics, and fleet maintenance people who already turn wrenches on heavy equipment. If you’re just operating the machine or only doing daily/250‑hour service, you really want the Operation & Maintenance Manual instead, not this level of detail.
FAQ
Q: Is this a PDF I can search and print?
A: Yes, this kind of shop manual is normally supplied as a searchable PDF that you can print specific sections for use in the shop.
Q: Is it detailed enough for a full rebuild?
A: The Komatsu PC450LC-8 Crawler Excavator Shop Manual usually covers workshop-level diagnostics, disassembly, inspection, and reassembly procedures for major systems.
Q: How do I know it matches my machine version?
A: You’ll need to match your machine’s ID plate and serial range against the book reference SEN02223-26; if they don’t line up, you should look for the correct variant.
Bottom line: if you’re doing real repair work or diagnostics on a PC450LC-8, this is the right manual; if you just want operating tips and routine service intervals, keep looking for the O&M book instead.
📘 Show Index
Table of Contents:
- 00 Index and foreword
- Index
- Composition of shop manual
- Table of contents
- Foreword and general information
- Safety notice
- How to read the shop manual
- Explanation of terms for maintenance standard
- Handling of electric equipment and hydraulic component
- Handling of connectors newly used for engines
- How to read electric wire code
- Precautions when carrying out operation
- Method of disassembling and connecting push-pull type coupler
- Standard tightening torque table
- Conversion table
- 01 Specification
- Specification and technical data
- Specification dimension drawings (Serial number: 70001 to 73000)
- Specification dimension drawings (Serial number: 73001 and up)
- Specifications (Serial number: 70001 to 73000)
- Specifications (Serial number: 73001 and up)
- Weight table (Serial number: 70001 to 73000)
- Weight table (Serial number: 73001 and up)
- Table of fuel, coolant and lubricants
- 10 Structure, function and maintenance standard
- Engine and cooling system
- Engine related parts
- Radiator, oil cooler and aftercooler
- Power train
- Power train
- Swing circle
- Swing machinery
- Final drive
- Sprocket
- Undercarriage and frame
- Track frame and recoil spring
- Idler
- Carrier roller
- Track roller
- Track shoe
- Hydraulic system, Part 1
- Hydraulic equipment layout drawing
- Hydraulic tank and filter
- Hydraulic pump
- Hydraulic system, Part 2
- Control valve
- CLSS
- Functions and operation by valve
- Merge-divider valve
- Attachment circuit selector valve
- Holding valve
- Hydraulic system, Part 3
- Valve control
- PPC valve
- Solenoid valve
- PPC accumulator
- Anti-drop valve for boom
- Anti-drop valve for arm
- Return oil filter
- Center swivel joint
- Travel motor
- Swing motor
- Hydraulic cylinder
- Work equipment
- Work equipment
- Dimensions of components
- Cab and its attachments
- Electrical system
- Engine control
- Electrical control system
- Monitor system
- Sensors
- KOMTRAX terminal system
- 20 Standard value table
- Standard service value table
- Standard value table for engine
- Standard value table for chassis related parts
- Standard value table for chassis related parts (Loading shovel specification)
- 30 Testing and adjusting
- Testing and adjusting, Part 1
- Tools for testing, adjusting and troubleshooting
- Sketches of special tools
- Testing engine speed
- Testing air boost pressure
- Testing exhaust temperature
- Testing exhaust gas color
- Adjusting valve clearance
- Testing compression pressure
- Testing blow-by pressure
- Testing engine oil pressure
- Testing EGR valve drive pressure
- Handling fuel system parts
- Releasing residual pressure from fuel system
- Testing fuel pressure
- Handling during cylinder cut-out operation
- Handling during no injection cranking operation
- Testing fuel return and leakage
- Bleeding air from fuel circuit
- Checking fuel circuit for leakage
- Checking and adjusting fan belt and alternator belt
- Checking and adjusting air conditioner compressor belt tension
- Testing swing circle bearing clearance
- Checking and adjusting track shoe tension
- Testing and adjustment oil pressure in work equipment, swing, and travel circuits
- Testing control circuit basic pressure
- Checking and adjusting pump PC control circuit oil pressure
- Checking and adjusting pump LS control circuit oil pressure
- Testing solenoid valve output pressure
- Testing PPC valve output pressure
- Adjusting play of work equipment and swing PPC valves
- Inspecting locations of hydraulic drift of work equipment
- Releasing residual pressure from hydraulic circuit
- Testing oil leakage amount
- Bleeding air from various parts
- Testing and charging accumulator (manufactured by NOK) nitrogen gas pressure for attachment (low pressure side)
- Testing and charging accumulator nitrogen gas pressure for attachment (high pressure side)
- Replacing accumulator bladder on high pressure side for accumulator piping
- Testing and adjusting, Part 2
- Special functions of machine monitor
- Testing and adjusting, Part 3
- Handling voltage circuit of engine controller
- Preparation work for troubleshooting of electrical system
- Procedure for testing diodes
- Pm Clinic service
- Undercarriage troubleshooting report
- 40 Troubleshooting
- Failure code table and fuse locations
- Failure code table
- Fuse locations
- General Information on troubleshooting
- Points to remember when troubleshooting
- Sequence of events in troubleshooting
- Check before troubleshooting
- Checking water pump for water leakage
- Classification and troubleshooting steps
- Information in troubleshooting table
- Possible problems and troubleshooting No.
- Connection table for connector pin numbers
- T- branch box and T- branch adapter table
- Troubleshooting by failure code, Part 1
- Failure code [989L00] Engine Controller Lock Caution 1
- Failure code [989M00] Engine Controller Lock Caution 2
- Failure code [989N00] Engine Controller Lock Caution 3
- Failure code [AA10NX] Air cleaner Clogging
- Failure code [AB00KE] Charge Voltage Low
- Failure code [B@BAZG] Eng Oil Press Low
- Failure code [B@BAZK] Eng Oil Level Low
- Failure code [B@BCNS] Eng Water Overheat
- Failure code [B@BCZK] Eng Water Level Low
- Failure code [B@HANS] Hydr Oil Overheat
- Failure code [CA111] EMC Critical Internal Failure
- Failure code [CA115] Eng Ne and Bkup Speed Sens Error
- Failure code [CA122] Chg Air Press Sensor High Error
- Failure code [CA123] Chg Air Press Sensor Low Error
- Failure code [CA131] Throttle Sensor High Error
- Failure code [CA132] Throttle Sensor Low Error
- Failure code [CA135] Eng Oil Press Sensor High Error
- Failure code [CA141] Eng Oil Press Sensor Low Error
- Failure code [CA144] Coolant Temp Sensor High Error
- Failure code [CA145] Coolant Temp Sensor Low Error
- Failure code [CA153] Chg Air Temp Sensor High Error
- Failure code [CA154] Chg Air Temp Sensor Low Error
- Failure code [CA187] Sens Supply 2 Volt Low Error
- Failure code [CA221] Ambient Press Sens High Error
- Failure code [CA222] Ambient Press Sens Low Error
- Failure code [CA227] Sens Supply 2 Volt High Error
- Failure code [CA234] Eng Overspeed
- Failure code [CA238] Ne Speed Sens Supply Volt Error
- Failure code [CA263] Fuel Temp Sensor High Error
- Failure code [CA265] Fuel Temp Sensor Low Error
- Failure code [CA271] IMV/PCV1 Short Error
- Failure code [CA272] IMV/PCV1 Open Error
- Failure code [CA273] PCV2 Short Error
- Failure code [CA274] PCV2 Open Error
- Failure code [CA322] Inj #1 Open/Short Error
- Failure code [CA323] Inj #5 (L/B#5) Open/Short Error
- Failure code [CA324] Inj #3 (L/B#3) Open/Short Error
- Failure code [CA325] Inj #6 Open/Short Error
- Failure code [CA331] Inj #2 Open/Short Error
- Failure code [CA332] Inj #4 Open/Short Error
- Troubleshooting by failure code, Part 2
- Failure code [CA342] Calibration Code Incompatibility
- Failure code [CA351] Injectors Drive Circuit Error
- Failure code [CA352] Sens Supply 1 Volt Low Error
- Failure code [CA386] Sens Supply 1 Volt High Error
- Failure code [CA441] Battery Voltage Low Error
- Failure code [CA442] Battery Voltage High Error
- Failure code [CA449] Rail Press Very High Error
- Failure code [CA451] Rail Press Sensor High Error
- Failure code [CA452] Rail Press Sensor Low Error
- Failure code [CA553] Rail Press High Error
- Failure code [CA554] Rail Press Sensor In Range Error
- Failure code [CA559] Rail Press Low Error
- Failure code [CA689] Eng Ne Speed Sensor Error
- Failure code [CA731] Eng Bkup Speed Sens Phase Error
- Failure code [CA757] All Continuous Data Lost Error
- Failure code [CA778] Eng Bkup Speed Sensor Error
- Failure code [CA1228] EGR valve servo error 1
- Failure code [CA1625] EGR valve servo error 2
- Failure code [CA1633] KOMNET Datalink Timeout Error
- Failure code [CA2185] Throt Sens Sup Volt High Error
- Failure code [CA2186] Throt Sens Sup Volt Low Error
- Failure code [CA2249] Rail Press Very Low Error
- Failure code [CA2271] EGR valve lift sensor high error
- Failure code [CA2272] EGR valve lift sensor low error
- Failure code [CA2351] EGR valve solenoid operation short circuit
- Failure code [CA2352] EGR valve solenoid operation disconnect
- Failure code [CA2555] Grid Htr Relay Volt Low Error
- Failure code [CA2556] Grid Htr Relay Volt High Error
- Failure code [D110KB] Battery Relay Drive S/C
- Failure code [D19JKZ] Personal Code Relay Abnormality
- Failure code [D862KA] GPS Antenna Discon
- Failure code [DA22KK] Pump Solenoid Power Low Error
- Failure code [DA25KP] 5V sensor power supply output 1 abnormality
- Failure code [DA29KQ] Model Selection Abnormality
- Troubleshooting by failure code, Part 3
- Failure code [DA2RMC] CAN Discon (Pump con detected)
- Failure code [DAF8KB] Short circuit in camera power supply
- Failure code [DAFGMC] GPS Module Error
- Failure code [DAFRMC] CAN discon (Monitor detected)
- Failure code [DGH2KB] Hyd Oil Sensor Short
- Failure code [DHPAMA] F Pump Press Sensor Abnormality
- Failure code [DHPBMA] R Pump Press Sensor Abnormality
- Failure code [DHS3MA] Arm Curl PPC Press Sensor Abnormality
- Failure code [DHS4MA] Bucket Curl PPC Press Sensor Abnormality
- Failure code [DHX1MA] Overload Sensor Abnormality (Analog)
- Failure code [DW43KA] Travel Speed Sol. Open Circuit
- Failure code [DW43KB] Travel Speed Sol. Short Circuit
- Failure code [DW45KA] Swing Brake Sol. Open Circuit
- Failure code [DW45KB] Swing Brake Sol. Short Circuit
- Failure code [DW91KA] Travel Junction Sol.Open Circuit
- Failure code [DW91KB] Travel Junction Sol. Short Circuit
- Failure code [DWA2KA] Attachment Sol Open Circuit
- Failure code [DWA2KB] Attachment Sol Short Circuit
- Failure code [DWJ0KA] Merge-divider Sol. Open Circuit
- Failure code [DWJ0KB] Merge-divider Sol. Short Circuit
- Failure code [DWK0KA] 2-stage Relief Sol. Open Circuit
- Failure code [DWK0KB] 2-stage Relief Sol. Short Circuit
- Failure code [DXA0KA] PC-EPC Sol. Open Circuit
- Failure code [DXA0KB] PC-EPC Sol. Short Circuit
- Failure code [DXE0KA] LS-EPC Sol. Open Circuit
- Failure code [DXE0KB] LS-EPC Sol. Short Circuit
- Failure code [DXE4KA] Service Current EPC Open Circuit
- Failure code [DXE4KB] Service Current EPC Short Circuit
- Failure code [DY20KA] Wiper Working Abnormality
- Failure code [DY20MA] Wiper Parking Abnormality
- Failure code [DY2CKA] Washer Drive Open Discon
- Failure code [DY2CKB] Washer Drive Short Circuit
- Failure code [DY2DKB] Wiper Drive (Fwd) Short Circuit
- Failure code [DY2EKB] Wiper Drive (Rev) Short Circuit
- Troubleshooting of electrical system (E-mode)
- Before carrying out troubleshooting of electrical system
- Information contained in troubleshooting table
- E-1 Engine does not start
- E-2 Auto-decelerator does not operate
- E-3 Automatic warming-up system does not operate
- E-4 Preheater does not operate
- E-5 All work equipment, swing, and travel mechanism do not move
- E-6 Power maximizing function does not operate
- E-7 Machine monitor does not display at all
- E-8 Machine monitor does not display some items
- E-9 Contents of display by machine monitor are different from applicable machine
- E-10 Fuel level monitor was lighted in red while engine running
- E-11 Engine coolant temperature gauge does not indicate normally
- E-12 Hydraulic oil temperature gauge does not indicate normally
- E-13 Fuel level gauge does not indicate normally
- E-14 Swing lock monitor does not indicate normally
- E-15 When monitor switch is operated, monitor displays nothing
- E-16 Windshield wiper and window washer do not operate
- E-17 Machine push-up function does not operate normally
- E-18 Monitoring function fails to display “boom raise” normally
- E-19 Monitoring function fails to display “boom lower” normally
- E-20 Monitoring function fails to display “arm IN” normally
- E-21 Monitoring function fails to display “arm OUT” normally
- E-22 Monitoring function fails to display “bucket CURL” normally
- E-23 Monitoring function fails to display “bucket DUMP” normally
- E-24 Monitoring function fails to display “swing” normally
- E-25 Monitoring function fails to display “travel” normally
- E-26 Monitoring function fails to display “travel differential pressure” normally
- E-27 Monitoring function fails to display “service” normally
- E-28 KOMTRAX system does not operate normally
- E-29 Air conditioner does not operate
- E-30 Travel alarm does not sound or does not stop sounding
- E-31 Horn does not sound
- Troubleshooting of hydraulic and mechanical system (H-mode)
- System chart for hydraulic and mechanical system
- Information contained in troubleshooting table
- H-1 All work equipment lack power, or travel and swing speeds are slow
- H-2 Engine speed sharply drops or engine stalls
- H-3 No work equipment, swing or travel move
- H-4 Abnormal noise is heard from around hydraulic pump
- H-5 Auto-decelerator does not work
- H-6 Fine control mode does not function or responds slow
- H-7 Boom moves slowly or lacks power
- H-8 Arm moves slowly or lacks power
- H-9 Bucket moves slowly or lacks power
- H-10 Work equipment does not move in its single operation
- H-11 Work equipment has a bit too fast hydraulic drift
- H-12 Work equipment has big time lag
- H-13 Other work equipment moves when relieving single circuit
- H-14 Power max. switch does not operate
- H-15 Machine push-up function does not operate.
- H-16 In compound operation of work equipment, speed of part loaded more is low
- H-17 When machine swings and raises boom simultaneously, boom rising speed is low
- H-18 When machine swings and travels simultaneously, travel speed lowers largely
- H-19 Machine deviates during travel
- H-20 Travel speed is low
- H-21 Machine is not steered well or steering power is low
- H-22 Travel speed does not change or travel speed is low or high
- H-23 Travel system does not move (only one side)
- H-24 Upper structure does not swing
- H-25 Swing acceleration or swing speed is low
- H-26 Upper structure overruns remarkably when it stops swinging
- H-27 Large shock is made when upper structure stops swinging
- H-28 Large sound is made when upper structure stops swinging.
- H-29 Hydraulic drift of swing is large
- H-30 Attachment circuit is not changed
- H-31 Oil flow in attachment circuit cannot be controlled
- Troubleshooting of engine (S-mode)
- Method of using troubleshooting chart
- S-1 Starting performance is poor
- S-2 Engine does not start
- S-3 Engine does not pick up smoothly
- S-4 Engine stops during operations
- S-5 Engine does not rotate smoothly
- S-6 Engine lacks output (or lacks power)
- S-7 Exhaust smoke is black (incomplete combustion)
- S-8 Oil consumption is excessive (or exhaust smoke is blue)
- S-9 Oil becomes contaminated quickly
- S-10 Fuel consumption is excessive
- S-11 Oil is in coolant (or coolant spurts back or coolant level goes down)
- S-12 Oil pressure drops
- S-13 Oil level rises (Entry of coolant or fuel)
- S-14 Coolant temperature becomes too high (overheating)
- S-15 Abnormal noise is made
- S-16 Vibration is excessive
- 50 Disassembly and assembly
- General information on disassembly andassembly
- How to read this manual
- Coating materials list
- Special tool list
- Sketches of special tools
- Engine and cooling system
- Removal and installation of fuel supply pump assembly
- Removal and installation of fuel injector assembly
- Removal and installation of engine front seal
- Removal and installation of engine rear seal
- Removal and installation of cylinder head assembly
- Removal and installation of muffler assembly
- Removal and installation of radiator assembly
- Removal and installation of hydraulic oil cooler assembly
- Removal and installation of aftercooler assembly
- Removal and installation of engine and hydraulic oil pump assembly
- Power train
- Removal and installation of travel motor and final drive assembly
- Disassembly and assembly of final drive assembly
- Removal and installation of swing motor and swing machinery assembly
- Disassembly and assembly of swing motor and swing machinery assembly
- Removal and installation of swing circle assembly
- Undercarriage and frame
- Disassembly and assembly of carrier roller assembly
- Disassembly and assembly of track roller assembly
- Disassembly and assembly of idler assembly
- Disassembly and assembly of recoil spring assembly
- Removal and installation of sprocket
- Expansion and installation of track shoe assembly
- Removal and installation of revolving frame assembly
- Removal and installation of counterweight assembly
- Hydraulic system
- Removal and installation of center swivel joint assembly
- Disassembly and assembly of center swivel joint assembly
- Removal and installation of hydraulic tank assembly
- Removal and installation of control valve assembly
- Disassembly and assembly of control valve assembly
- Removal and installation of hydraulic pump assembly
- Removal and installation of oil seal in hydraulic pump input shaft
- Disassembly and assembly of work equipment PPC valve assembly
- Disassembly and assembly of travel PPC valve assembly
- Disassembly and assembly of hydraulic cylinder assembly
- Work equipment
- Removal and installation of work equipment assembly
- Removal and installation of anti- drop valve assembly for boom
- Removal and installation of anti- drop valve assembly for arm
- Disassembly and assembly of anti-drop valve assembly
- Cab and its attachments
- Removal and installation of operator cab assembly
- Removal and installation of operator cab glass (stuck glass)
- Removal and installation of front window assembly
- Removal and installation of floor frame assembly
- Removal and installation of work equipment control lever assembly
- Electrical system
- Removal and installation of air conditioner unit assembly
- Removal and installation of KOMTRAX communication modem assembly
- Removal and installation of monitor assembly
- Removal and installation of pump controller assembly
- Removal and installation of engine controller
- 80 Appendix
- Combustion-type heater
- Handling combustion-type heater
- Overall layout of preheating device and flow of engine coolant
- Structure and function of combustion-type heater
- Electrical circuit diagram
- Operation and function
- Overheat prevention function
- Troubleshooting and repair instructions
- Electrical circuit diagram of combustion-type heater
- 90 Diagrams and drawings
- Hydraulic diagrams and drawings
- Hydraulic circuit diagram
- Electrical diagrams and drawings
- Electrical circuit diagram
- Connector list and stereogram
Komatsu
