On a 425 mini excavator, this is the book you grab when the boom drifts down, a drive motor gets weak, or you've got an electrical gremlin and downtime is killing you. Around my shop, I reach for the service manual when I need the exact teardown order, test ports, or torque pattern, not just where the fuel cap is. If you're trying to keep an older 425 alive without hauling it to the dealer every time, this is the level of detail you want.
What this manual helps you do
- Diagnose hydraulic problems, check pressures, and trace internal leaks in the 425's working and travel circuits
- Follow step-by-step teardown and reassembly on major components like cylinders, drive motors, swing motor, and final drives
- Troubleshoot electrical issues using wiring diagrams, connector callouts, and test procedures with a basic meter
- Replace and set up wear parts correctly, including seals, bushings, and bearings, with the right sequences and specs
- Verify adjustments after a repair so the machine digs straight, tracks right, and runs at proper engine and hydraulic settings
Who this is for
This is for a small contractor, owner-operator, field tech, or shop mechanic working on a Bobcat 425 excavator with serial number AACJ11001 through AACJ99999. If you just need operating tips, safety info, or basic maintenance intervals, you want the operator's handbook instead.
FAQ
Q: Is this a searchable PDF, and can I read the wiring diagrams clearly?
A: Yes, it's a PDF you can search by keyword, and the wiring diagrams are zoomable so you can read wire colors and pin labels.
Q: How do I know it fits my exact 425?
A: Check your serial plate. If it starts with AACJ and falls between AACJ11001 and AACJ99999, this manual matches your machine.
Q: Is this the right document if I'm doing real repairs, not just oil changes?
A: Yes, this is the workshop service manual, meant for diagnostics and component repair, not routine greasing and walk-around checks.
Bottom line: If your 425's serial is in that AACJ11001-AACJ99999 range and you're actually turning wrenches on it, this is the right manual. If not, skip it.
📘 Show Index
Table of Contents:
- CONTENTS
- FOREWORD
- FOREWORD
- SAFETY INSTRUCTIONS
- FIRE PREVENTION
- Maintenance
- Operation
- Electrical
- Hydraulic System
- Fueling
- Starting
- Spark Arrester Exhaust System
- Welding And Grinding
- Fire Extinguishers
- SERIAL NUMBER LOCATIONS
- Excavator Serial Number
- Engine Serial Number
- DELIVERY REPORT
- EXCAVATOR IDENTIFICATION
- SAFETY & MAINTENANCE
- LIFTING AND BLOCKING THE EXCAVATOR
- UPPERSTRUCTURE SLEW LOCK
- LIFTING THE EXCAVATOR
- OPERATOR CAB (ROPS / TOPS)
- Description
- Cab Door
- Front Window
- Front Wiper
- Window Washer Reservoir
- Right Side Window
- Right Front Window
- Heating, Ventilation, And Air Conditioning Duct
- TRANSPORTING THE EXCAVATOR ON A TRAILER
- Loading And Unloading
- Fastening
- TAILGATE
- RIGHT SIDE COVER
- SERVICE SCHEDULE
- AIR CLEANER SERVICE
- Daily Check
- Replacing Filter Elements
- ENGINE COOLING SYSTEM
- Cleaning
- Checking Level
- Removing And Replacing Coolant
- FUEL SYSTEM
- Fuel Specifications
- Biodiesel Blend Fuel
- Filling The Fuel Tank
- Fuel Filters
- Draining The Fuel Tank
- Removing Air From The Fuel System
- ENGINE LUBRICATION SYSTEM
- Checking And Adding Engine Oil
- Engine Oil Chart
- Removing And Replacing Oil Filter
- HYDRAULIC SYSTEM
- Checking And Adding Fluid
- Hydraulic Fluid Chart
- Removing And Replacing The Hydraulic Filter
- Removing And Replacing The Case Drain Filter
- Removing And Replacing The Hydraulic Fluid
- LUBRICATING THE EXCAVATOR
- TRAVEL MOTOR
- Checking And Adding Oil
- Removing And Replacing Oil
- SPARK ARRESTER MUFFLER
- ALTERNATOR BELT
- Belt Adjustment
- Belt Replacement
- SEAT BELT
- Inspection And Maintenance
- MOTION ALARM SYSTEM (IF EQUIPPED)
- Description
- Inspecting
- Adjusting Switch Position
- EXCAVATOR STORAGE AND RETURN TO SERVICE
- Storage
- Return To Service
- STOPPING THE ENGINE AND LEAVING THE EXCAVATOR
- Procedure
- Emergency Exits
- MOTION ALARM SYSTEM (IF EQUIPPED)
- Description
- Inspecting
- Adjusting Switch Position
- HYDRAULIC SYSTEM
- HYDRAULIC/HYDROSTATIC SCHEMATICS
- HYDRAULIC SYSTEM INFORMATION
- Glossary Of Hydraulic / Hydrostatic Symbols
- Troubleshooting The Hydraulic Circuit
- Troubleshooting The Cylinder Circuit
- Troubleshooting The Swing (Upperstructure Slew) Circuit
- Troubleshooting The Travel Circuit
- CYLINDER (BOOM)
- Testing
- Removal And Installation
- Parts Identification
- Disassembly
- Assembly
- CYLINDER (ARM)
- Testing
- Removal And Installation
- Parts Identification
- Disassembly
- Assembly
- CYLINDER (BOOM SWING)
- Testing
- Removal And Installation
- Parts Identification
- Disassembly
- Assembly
- CYLINDER (BUCKET)
- Testing
- Removal And Installation
- Parts Identification
- Disassembly
- Assembly
- CYLINDER (BLADE)
- Testing
- Removal And Installation
- Parts Identification
- Disassembly
- Assembly
- VALVE (MAIN RELIEF)
- Testing And Adjusting The Main Relief Valve
- VALVE (PORT RELIEF)
- Testing And Adjusting Port Relief Valve Pressure
- VALVE (CROSSPORT RELIEF)
- Testing And Adjusting The Crossport Relief Valves
- 425 With Standard Arm
- 425, 428 With Long Arm
- VALVE (PRESSURE REDUCING)
- Testing And Adjusting The Pressure Reducing Valve
- HYDRAULIC CONTROL VALVE
- Description
- Removal And Installation
- Parts Identification
- Disassembly
- Right Travel Valve Section Disassembly And Assembly
- Left Travel Valve Section Disassembly And Assembly
- Blade Valve Section Disassembly And Assembly
- Slew Valve Section Disassembly And Assembly
- Auxiliary Valve Section Disassembly And Assembly
- Bucket Valve Section Disassembly And Assembly
- Arm Valve Section Disassembly And Assembly
- Boom Valve Section Disassembly And Assembly
- Boom Swing Valve Section Disassembly And Assembly
- Inlet Section Disassembly And Assembly
- Assembly
- HYDRAULIC PUMP
- Description
- Torque Adjustment
- Testing The Piston Pump
- Testing Auxiliary Hydraulic Flow
- Removal
- Installation
- Coupler Removal And Installation
- Hydraulic Pump Start Up
- Parts Identification (Piston Pump)
- Disassembly
- Piston Pump Disassembly
- Piston Pump Assembly
- Assembly
- MANIFOLD ASSEMBLY / ACCUMULATOR
- Description
- Removal And Installation
- Parts Identification
- Disassembly And Assembly
- TRAVEL MOTOR
- Description
- Removal And Installation
- Parts Identification
- Disassembly
- Assembly
- SWIVEL JOINT
- Description
- Removal And Installation
- Parts Identification
- Disassembly
- Assembly
- SWING MOTOR
- Description
- Removal And Installation
- Parts Identification
- Disassembly
- Assembly
- SWING MOTOR (DRIVE CARRIER)
- Description
- Removal And Installation
- Parts Identification
- Disassembly
- Assembly
- CONTROL PATTERN SELECTOR VALVE
- Description
- Removal And Installation
- Parts Identification
- Disassembly And Assembly
- RIGHT CONTROL LEVER (JOYSTICK)
- Description
- Testing
- Handle Removal And Installation
- Removal And Installation
- Parts Identification
- Disassembly
- Assembly
- LEFT CONTROL LEVER (JOYSTICK)
- Description
- Testing
- Handle Removal And Installation
- Removal And Installation
- Parts Identification
- Disassembly
- Assembly
- TRAVEL CONTROL VALVE
- Removal And Installation
- Parts Identification
- Disassembly And Assembly
- HYDRAULIC FILTER
- Description
- Housing Removal And Installation
- CASE DRAIN FILTER
- Description
- Removal And Installation
- HYDRAULIC RESERVOIR
- Description
- Removal And Installation
- OIL COOLER
- Description
- Removal And Installation
- DIRECT TO TANK VALVE
- Description
- Removal And Installation
- Parts Identification
- Disassembly And Assembly
- NON-PRESSURIZED ACCUMULATOR
- Description
- Removal And Installation
- HYDRAULIC X-CHANGE VALVE
- Removal And Installation
- Parts Identification
- Disassembly
- Assembly
- CASE DRAIN FILTER MOUNT
- UNDERCARRIAGE
- BLADE
- Description
- Removal And Installation
- TRACK FRAME COMPONENTS
- Description
- Track Lug Height
- Checking Tension
- Adjusting Tension
- Rubber Track Removal And Installation
- Steel Track Removal And Installation
- Idler (Front) Removal And Installation
- Idler (Front) Parts Identification
- Idler (Front) Disassembly
- Idler (Front) Assembly
- Coil Spring Assembly And Cylinder Disassembly And Assembly (AACJ11223 & Below, A9K311309 & Below And A9K411308 & Below)
- Coil Spring Cylinder Parts Identification (AACS11224 & Above, A9K311310 & Above And A9K411309 & Above)
- Coil Spring Assembly And Cylinder Disassembly And Assembly (AACJ11224 & Above, A9K311310 & Above And A9K411309 & Above)
- Roller Removal And Installation (AACJ13005 & Below, A9K313003 & Below And A9K413005 & Below)
- Roller Removal And Installation (AACJ13006 & Above, A9K313004 & Above And A9K413006 & Above)
- Roller Parts Identification (AACJ13005 & Below, A9K313003 & Below And A9K413005 & Below)
- Roller Disassembly (AACJ13005 & Below, A9K313003 & Below And A9K413005 & Below)
- Roller Assembly (AACJ13005 & Below, A9K313003 & Below And A9K413005 & Below)
- Track Guide Removal And Installation
- Sprocket Removal And Installation
- Track Damage Identification
- SWING CIRCLE GEAR
- UPPERSTRUCTURE AND SWING SECTION
- UPPERSTRUCTURE
- Description
- Removal
- Installation
- CANOPY
- CAB
- Removal And Installation
- Door Removal And Installation
- Front Window Removal And Installation
- Right Side Rear Sliding Window Removal And Installation
- Right Side Front Sliding Window Removal And Installation
- Glass Removal
- Right Side Front And Rear Sliding Window Weather Strip Removal And Installation
- Right Side Front And Rear Sliding Window Wiper Strip Removal And Installation
- Glass Installation
- SEAT AND SEAT MOUNT
- Seat Mount Removal And Installation
- Seat Removal And Installation
- RIGHT CONSOLE
- Description
- Console Cover Removal And Installation
- Console Base Cover Removal And Installation
- LEFT CONSOLE
- Description
- Joystick Console Cover (Bottom) Removal And Installation
- Joystick Console Cover (Top) Removal And Installation
- Compression Spring Removal And Installation
- Compression Spring Disassembly And Assembly
- Lever Removal And Installation
- Joystick Console Frame Removal And Installation
- Joystick Console Frame Disassembly And Installation
- Left Rear Console Cover Removal And Installation
- Left Rear Console Frame Removal And Installation
- Left Rear Console Frame Disassembly And Assembly
- BLADE CONTROL
- Removal And Installation
- Disassembly And Assembly
- Linkage Removal And Installation
- Linkage Disassembly And Assembly
- UPPERSTRUCTURE SLEW LOCK
- FLOOR MAT AND FLOOR PANEL
- Description
- Removal And Installation
- BOOM SWING PEDAL
- Description
- Removal And Installation
- Disassembly And Assembly
- Linkage Removal And Installation
- TRAVEL LEVER / PEDALS
- Description
- Removal And Installation
- Disassembly And Assembly
- Adjustment
- Linkage Removal And Installation
- FUEL TANK
- HORN
- SWING FRAME
- Description
- Removal And Installation
- Hose Routing
- Bushing Removal And Installation
- Swing Frame Bushing Removal And Installation
- BOOM
- Description
- Removal And Installation
- ARM
- Description
- Removal And Installation
- Arm To Boom Bushing Removal And Installation
- Arm To Bucket And Bucket Link Bushing Removal And Installation
- BUCKET
- Removal And Installation (Pin-On X-Change)
- Removal And Installation (Bolt-On X-Change)
- Removal And Installation (Pin-On Attachment)
- Bucket Teeth Removal And Installation
- Bucket Side Cutting Edge Removal And Installation
- CLAMP
- TAILGATE
- Removal And Installation
- Latch Removal And Installation
- X-CHANGE
- Pin-On Removal And Installation
- Pin-On Disassembly And Assembly
- RIGHT SIDE COVER
- Removal And Installation
- Latch Removal And Installation
- COUNTERWEIGHT
- Description
- Removal And Installation (Long Arm Counterweight)
- Removal And Installation (Standard Counterweight)
- ELECTRICAL SYSTEM & ANALYSIS
- ELECTRICAL SCHEMATICS
- ELECTRICAL SYSTEM INFORMATION
- Glossary Of Electrical Symbols
- Harness Connectors
- Troubleshooting
- Description
- Fuse And Relay Location / Identification
- BATTERY
- Removal And Installation
- Servicing
- Using A Booster Battery (Jump Starting)
- ALTERNATOR
- Belt Adjustment
- Belt Replacement
- Charging System Inspection
- Description
- Tests
- Alternator Output Test
- Full Field Test
- Alternator Regulator Test
- Alternator Regulator Test With Voltmeter
- Removal And Installation
- Parts Identification
- STARTER
- Testing
- Removal And Installation
- Parts Identification
- LIGHTS
- Removal And Installation
- Boom Light Removal And Installation
- Boom Light Bulb Replacement
- MAGNETIC LOCKOUT SENSOR
- Testing Left Console Magnetic Lockout Sensor
- Left Console Magnetic Lockout Sensor Removal And Installation
- FUEL LEVEL SENDER
- Removal And Installation
- Testing
- DIAGNOSTIC SERVICE CODES
- Description
- Service Codes List
- ENGINE SERVICE
- ENGINE INFORMATION
- Description
- Specifications
- Torque Values
- Troubleshooting
- Removal And Installation
- Engine Mount Replacement
- Compression – Checking
- ENGINE SPEED CONTROL
- SPARK ARRESTER MUFFLER
- AIR CLEANER
- ENGINE COOLING SYSTEM
- Radiator Removal And Installation
- Radiator Disassembly And Assembly
- Water Pump Removal And Installation
- Water Pump Disassembly And Assembly
- Thermostat Housing Removal And Installation
- Testing The Thermostat
- LUBRICATION SYSTEM
- Oil Pan Removal And Installation
- Oil Pump Removal And Installation
- Oil Pump Inspection
- Engine Oil Pressure – Testing
- FUEL SYSTEM
- Fuel Camshaft Removal And Installation
- Fuel Camshaft Governor Disassembly And Assembly
- Fuel Shutoff Solenoid – Checking
- Fuel Shutoff Solenoid Removal And Installation
- Fuel Injection Pump Removal And Installation
- Timing The Injection Pump
- Fuel Injector Removal And Installation
- Fuel Injector Nozzles Pressure – Checking
- Nozzle Spray Condition
- Valve Seat Tightness
- CYLINDER HEAD
- Glow Plug – Testing
- Glow Plug Removal And Installation
- Valve Clearance Adjustment
- Valve Timing – Checking
- Cylinder Head Removal And Installation
- Cylinder Head Disassembly And Assembly
- Cylinder Head – Servicing
- Cylinder Head Top Clearance
- Valve Guide – Checking
- Reconditioning The Valve And Valve Seat
- Valve Spring
- Valve Tappets
- Rocker Arm And Shaft – Checking
- CRANKSHAFT AND PISTONS
- Piston And Connecting Rod Removal And Installation
- Piston And Connecting Rod – Servicing
- Cylinder Bore Checking
- Connecting Rod Alignment
- Crankshaft And Bearings Removal And Installation
- Crankshaft And Bearings – Servicing
- CAMSHAFT AND TIMING GEARS
- Timing Gearcase Cover Removal And Installation
- Timing Gears Backlash – Checking
- Idler Gear And Shaft Removal And Installation
- Camshaft – Servicing
- Idler Gear And Shaft Servicing
- FLYWHEEL AND HOUSING
- Flywheel Housing Removal And Installation
- Hydraulic Pump Coupler Removal And Installation
- Flywheel Removal And Installation
- Rear End Plate Removal And Installation
- HEATING, VENTILATION & AIR CONDITIONING
- HEATER SYSTEM
- REGULAR MAINTENANCE
- Filter Element Removal And Installation
- Heater Coil
- TROUBLESHOOTING
- Blower Motor Does Not Operate
- Blower Motor Operates Normally, But Air Flow Is Insufficient
- Electrical System
- HEATER UNIT
- HEATER COIL
- BLOWER FAN
- HEATER VALVE
- SPECIFICATIONS
- EXCAVATOR SPECIFICATIONS
- 425 With Standard Arm
- 425, 428 With Long Arm Option
- Performance
- Controls
- Engine
- Hydraulic System
- Hydraulic Cylinders
- Hydraulic Cycle Times
- Electrical
- Instrumentation
- Drive System
- Slew System
- Undercarriage
- Crawler Track Design
- Capacities
- Fuel Tank
- Tracks
- Type
- Ground Pressure
- TORQUE SPECIFICATIONS FOR BOLTS
- Torque For General SAE Bolts
- Torque For General Metric Bolts
- HYDRAULIC CONNECTION SPECIFICATIONS
- O-ring Face Seal Connection
- Straight Thread O-ring Fitting
- Tubelines And Hoses
- Flare Fitting
- Port Seal Fitting
- HYDRAULIC FLUID SPECIFICATIONS
- CONVERSIONS
- Decimal And Millimeter Equivalents
- U.S. To Metric Conversion Chart
- SERVICE TOOLS REQUIRED
- Remote Start Tools
- Hydraulic Tools
- Engine Tools
- HVAC Tools
- ALPHABETICAL INDEX
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