Komatsu 1D84-1B(S/N 00101-UP)
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu 1D84-1B is a diesel engine used in the PC03-1 mini excavator class, a compact machine designed for utility and municipal work. Production for this specific engine serial range began in 1991. The PC03-1 sits in the compact equipment category, typically weighing under 20,000 lbs, and serves as a predecessor to later mini-excavator generations like the PC50 series. Configurations offered for this class include standard and low-ground-pressure track setups, with varying bucket and arm options to suit tight access jobsites.
Across the Komatsu mini-excavator lineage, the 1D84-1B represents an earlier generation of powertrain technology compared to modern Tier 4 Final engines. While newer models feature advanced electronic controls and emissions systems, the 1D84-1B relies on robust mechanical fuel delivery and simpler hydraulic architectures. This machine remains significant in the used and parts market because its mechanical simplicity allows for easier field repairs and lower maintenance costs, making it a durable choice for contractors who prioritize uptime and serviceability over complex emissions compliance.
Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.
Komatsu 1D84-1B(S/N 00101-UP) specifications
Engine
| Model | 1D84-1B |
| Gross Power | 5.5 kW (7.4 HP) @ 2800 rpm |
| Displacement | 0.39 l (23.6 cu. inch) |
| Cylinders | 1 |
| Emissions Tier | Not documented for this exact serial range — verify with your dealer |
Weights
| Operating Weight | Not documented for this exact serial range — verify with your dealer |
| Shipping Weight | Not documented for this exact serial range — verify with your dealer |
| Ground Pressure | Not documented for this exact serial range — verify with your dealer |
Dimensions
| Transport Length | Not documented for this exact serial range — verify with your dealer |
| Transport Width | Not documented for this exact serial range — verify with your dealer |
| Transport Height | Not documented for this exact serial range — verify with your dealer |
| Track Gauge | Not documented for this exact serial range — verify with your dealer |
| Ground Clearance | Not documented for this exact serial range — verify with your dealer |
Performance
| Travel Speeds | Not documented for this exact serial range — verify with your dealer |
| Gradeability | Not documented for this exact serial range — verify with your dealer |
Service capacities (summary)
| Fuel Tank | Not documented for this exact serial range — verify with your dealer |
| Hydraulic System | Not documented for this exact serial range — verify with your dealer |
| Engine Oil | Not documented for this exact serial range — verify with your dealer |
| Cooling System | Not documented for this exact serial range — verify with your dealer |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
Komatsu 1D84-1B(S/N 00101-UP) maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
Servicing the 1D84-1B(S/N 00101-UP) beyond the schedule
Predictive Maintenance & Fluid Analysis
Utilize KOWA fluid analysis at every 500-hour interval to monitor engine wear metals and hydraulic contamination. Check coolant SCA levels at 500 hours to prevent liner cavitation in the 1D84-1B block. Monitor hydraulic oil viscosity and particle count to protect the PC03-1’s piston pumps. Track fuel dilution in the engine oil to detect injector or piston ring wear early. Use KOMTRAX telematics data to correlate load frequency with fluid degradation rates for accurate service scheduling.
Corrective & Common Repairs
Address intermittent starting issues by inspecting the 1D84-1B starting motor and battery terminals. Replace hydraulic hoses showing cracks or leaks to prevent pressure loss in the PC03-1 system. Clean the air cleaner outer element to restore airflow if the restriction indicator triggers. Inspect the fuel water separator daily to prevent injector corrosion. Check track tension and roller alignment to correct uneven undercarriage wear on the PC03-1 chassis.
Overhaul & Rebuild Points
Plan engine overhaul when valve adjustment checks at 1,000 hours reveal excessive clearance or compression loss. Replace the turbocharger if inspection reveals shaft play or oil seal leakage. Rebuild the hydraulic pump if KOWA analysis shows high copper or iron levels. Inspect the swing machinery oil for metal particles indicating gear wear. Check final drive oil for grit or discoloration to determine if planetary gears require service.
Seasonal & Environment Servicing
In cold climates, verify coolant freeze protection and use appropriate viscosity engine oil for the 1D84-1B. Drain the fuel water separator more frequently in humid conditions to prevent microbial growth. In dusty environments, clean the radiator and oil cooler fins daily to prevent overheating. Check the air filter more often in high-dust jobsites. Inspect rubber tracks for hardening or cracking due to UV exposure and extreme temperatures.
1D84-1B(S/N 00101-UP) common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| YM114654-55600 | Fuel Filter Ass'Y | Fuel system service | Check fitment → |
| YM102103-55520 | O-Ring,(For Fuel Filter) | Fuel system service | Check fitment → |
| YM171051-92760 | Wrench,Fuel Filter? Water Separator | Fuel system service | Check fitment → |
| YM114650-12590 | Element Ass'Y | Scheduled service item | Check fitment → |
| YM114650-12540 | Element | Scheduled service item | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
1D84-1B(S/N 00101-UP) fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| CA111 | Engine Controller Internal Fault | Internal failure of the Electronic Control Module (ECM) hardware or logic. | Replace or reprogram the ECM. |
| CA115 | Engine Speed Sensor and Backup Speed Sensor Failure | Faulty crankshaft speed sensor, broken wiring, or corroded connector. | Replace the speed sensor and verify voltage at the pin connector. |
| CA441 | Battery Voltage Low Error | Weak battery, loose connections, or failing alternator. | Replace the battery or alternator; check the voltage regulator. |
| CA451 | Common Rail Pressure Sensor Feedback Value Too High | Malfunctioning rail pressure sensor or actual overpressure condition. | Diagnose the fuel rail pressure sensor or check pump lines. |
| B@BCNS | Engine Coolant Overheating | Low coolant level, blocked radiator fins, or failed fan belt. | Check radiator fins, fan belt, and coolant level. |
| AA10NX | Air Cleaner Clogging | Dirty or blocked air filter element. | Replace the air filter element. |
| E10 | Engine Controller Power Failure | Loss of power to the engine controller or drive system circuit malfunction. | Inspect ECM power connections, fuses, or ground wires. |
| CA234 | Engine Overspeed | Throttle calibration error, engine load cycle issue, or operator misuse. | Verify throttle calibration and engine load cycle. |
| CA122 | Intake Air Pressure Sensor High Error | Intake pressure sensor feedback voltage too high or sensor fault. | Verify the intake pressure sensor and wiring. |
| B@HANS | Hydraulic Oil Overheating | Contaminated hydraulic oil, clogged filter, or cooler fan failure. | Change hydraulic filter and oil; check cooler fan operation. |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
1D84-1B(S/N 00101-UP) attachments & work tools
Engine Identification
The machine designation 1D84-1B(S/N 00101-UP) identifies the specific engine model and serial range for this unit. The '1D84' prefix denotes the engine series, while '-1B' specifies the configuration variant within that series. Serial numbers starting from 00101 and continuing upward define the production batch for this specific engine configuration.
Work Tool Compatibility
The 1D84-1B engine is a power unit component and does not directly interface with work tools. Work tool compatibility is determined by the host machine model (e.g., PC03-1 excavator) that utilizes this engine. The source text references a '10 inch bucket' in the context of the PC03-1 model associated with this engine serial range, indicating the typical attachment class for the host equipment.
Hydraulic System Specifications
Komatsu hydraulic systems for this class typically utilize Komatsu Hydraulic Oil (HO) meeting KES 07.841.1 standards. The system requires ISO VG46 viscosity grade fluid for optimal performance across operating temperatures. Fluid specifications are critical for maintaining pump and valve longevity in excavator applications.
Engine Fluid Specifications
Diesel engine oil must meet Komatsu Engineering Standards, typically requiring SAE 10W or 15W-40 viscosity grades depending on ambient temperature. Powertrain oil and axle oil specifications include TO30 and AXO80 types respectively, ensuring compatibility with the transmission and final drive components associated with the host machine.
Cooling System Specifications
The cooling system requires Super-coolant AF-NAC meeting KES 07.892.1 standards. This coolant provides corrosion protection and heat transfer efficiency for the 1D84-1B engine block and cylinder head. Capacity varies by host machine configuration but is designed to maintain optimal operating temperatures under heavy load.
All 1D84-1B(S/N 00101-UP) assemblies by section
Every catalogued assembly group for the Komatsu 1D84-1B(S/N 00101-UP). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Cooling System
Komatsu : 1d84-1b(S/N 00101-Up) : Cooling System : Flywheel And Cooling Fan Case
| YM***01 | Case,Fan | 1 |
| YM***00 | Cushion | 4 |
| YM***92 | Flywheel Ass'Y | 1 |
Cylinder Block
Komatsu : 1d84-1b(S/N 00101-Up) : Cylinder Block : Balancer Shaft(#20101-)
| YM***34 | Bearing,Ball | 2 |
| YM***10 | Balancer Ass'Y | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Cylinder Block : Camshaft And Tappet(#20101-)
| YM***81 | Camshaft Ass'Y | 1 |
| YM***01 | Rod,Push | 2 |
| YM***60 | Tappet | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Cylinder Block : Crankshaft(#20101-)
| YM***02 | Bolt Plated | 1 |
| YM***00 | Crankshaft Ass'Y | 1 |
| YM***40 | Key | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Cylinder Block : Cylinder Block(#20101-)
| YM***40 | Cap Ass'Y,Oil Gauge | 1 |
| YM***20 | Seal | 1 |
| YM***08 | Seal,Oil | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Cylinder Block : Front Cover
| YM***40 | Cap Ass'Y,Oil Gauge | 1 |
| YM***51 | Sensor,Oil Pressure | 1 |
| YM***08 | Seal,Oil | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Cylinder Block : Piston And Connecting Rod
| YM***42 | Piston Ring Ass'Y | 1 |
| YM***23 | Piston Ass'Y | 1 |
| YM***02 | Piston Ring Ass'Y | 1 |
Cylinder Head
Komatsu : 1d84-1b(S/N 00101-Up) : Cylinder Head : Air Cleaner And Mounting
| YM***50 | Sponge | 1 |
| YM***50 | Nut | 1 |
| YM***60 | Washer,Seal | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Cylinder Head : Air Intake Manifold And Connection
| YM***02 | Screw | 2 |
| YM***52 | Stud | 2 |
| YM***02 | Nut | 2 |
Komatsu : 1d84-1b(S/N 00101-Up) : Cylinder Head : Cylinder Head
| YM***40 | Bolt | 2 |
| YM***00 | Valve,Intake | 1 |
| YM***80 | Retainer, Spring | 2 |
Komatsu : 1d84-1b(S/N 00101-Up) : Cylinder Head : Cylinder Head Cover
| YM***40 | Spring | 1 |
| YM***02 | Screw | 2 |
| YM***01 | Shaft | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Cylinder Head : Muffler And Mounting
| YM***00 | Gasket (Kit) | 1 |
| YM***00 | Muffler | 1 |
| YM***62 | Bolt,(For Shipping) | 6 |
Komatsu : 1d84-1b(S/N 00101-Up) : Cylinder Head : Rocker Arm
| YM***62 | Arm | 1 |
| YM***52 | Arm | 1 |
| YM***61 | Support,Rocker Arm | 1 |
Electrical System
Komatsu : 1d84-1b(S/N 00101-Up) : Electrical System : Dynamo And Mounting(#20101-)
| YM***90 | Dynamo Ass'Y | 1 |
| YM***42 | Screw | 3 |
| YM***30 | Stator | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Electrical System : Starting Motor
| YM***67 | Bolt | 2 |
| YM***10 | Starting Motor Ass'Y | 1 |
| YM***13 | Brush (-) | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Electrical System : Starting Motor And Mounting
| YM***02 | Screw | 2 |
| (Y***0) | Starting Motor Ass'Y,(See Fig.0661) | 1 |
Fuel System
Komatsu : 1d84-1b(S/N 00101-Up) : Fuel System : Fuel Feed Pump
| YM***00 | Feed Pump Ass'Y | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Fuel System : Fuel Filter
| YM***00 | Gasket | 2 |
| YM***00 | O-Ring (Kit) | 1 |
| YM***50 | Plug,Air | 2 |
Komatsu : 1d84-1b(S/N 00101-Up) : Fuel System : Fuel Injection Pump
| YM***20 | Packing | 1 |
| YM***50 | Seat | 1 |
| YM***08 | Pin,Spring | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Fuel System : Fuel Injection Pump And Piping
| YM***30 | Cover | 1 |
| YM***50 | Pipe | 1 |
| YM***02 | Nut | 3 |
Komatsu : 1d84-1b(S/N 00101-Up) : Fuel System : Fuel Nozzle And Spill Pipe
| YM***90 | Pipe | 1 |
| YM***00 | Holder Ass'Y | 1 |
| YM***20 | Spring | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Fuel System : Governor Control(#20101-)
| YM***00 | Governor Lever Ass'Y | 1 |
| YM***00 | Governor Ass'Y | 1 |
| YM***52 | Spring,Return | 1 |
Lubricating Oil System
Komatsu : 1d84-1b(S/N 00101-Up) : Lubricating Oil System : Lubricating Oil Filter
Komatsu : 1d84-1b(S/N 00101-Up) : Lubricating Oil System : Lubricating Oil Pump
| YM***70 | Cover | 1 |
| YM***70 | O-Ring (Kit) | 1 |
| YM***42 | Bolt | 3 |
Tool And Kit
Komatsu : 1d84-1b(S/N 00101-Up) : Tool And Kit : Gasket Kit
| YM***00 | Gasket (Kit) | 1 |
| YM***40 | Seal,Valve Stem (Kit) | 2 |
| YM***80 | O-Ring (Kit) | 1 |
Komatsu : 1d84-1b(S/N 00101-Up) : Tool And Kit : Tool
| YM***60 | Wrench,Fuel Filter? Water Separator | 1 |
| YM***21 | Puller,Flywheel | 1 |
| YM***54 | Bolt | 3 |
Frequently asked questions
What engine does the Komatsu 1D84-1B use?
The Komatsu 1D84-1B is the engine designation itself, a diesel power unit used in the PC03-1 mini excavator.
What is the operating weight of the machine using this engine?
Operating weight varies by configuration and attachment package; consult the specific serial range specification sheet for exact figures.
What replaced the Komatsu 1D84-1B engine?
Successor models in the Komatsu mini-excavator line utilize newer generation engines meeting modern emissions tiers, replacing the 1D84-1B in later production years.
What 1D84-1B(S/N 00101-UP) owners discuss
What are the common hydraulic behaviors and failure patterns associated with Komatsu excavators, particularly regarding performance when hot?
What undercarriage and wear patterns are typical for Komatsu crawler equipment?
What are the known engine quirks and common powertrain issues for Komatsu engines?
What are common electrical and sensor issues reported by Komatsu owners?
What specific items should be checked when buying a used Komatsu 1D84-1B(S/N 00101-UP)?
What safety-critical fixes or verifications are recommended for Komatsu hydraulic and engine systems?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
Need a specific 1D84-1B(S/N 00101-UP) part?
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