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Komatsu JW30-2(S/N 2001-UP)
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu JW30-2 (S/N 2001-UP) is a compact seven-wheel pneumatic (rubber-tired) roller built for asphalt finish-rolling and light compaction work, sitting at the small end of Komatsu's compaction equipment line alongside other small tandem and pneumatic rollers of its era. Operating weight runs approximately 3,000 kg (6,600 lb). Power comes from a Komatsu 3D78AE three-cylinder, water-cooled diesel producing roughly 16 kW (21-22 hp) at 2,400 rpm from 1.20 L displacement, running mechanical fuel injection with no electronic engine controls or fault-code readout. Drive is hydraulic with power steering, the pneumatic tires are staggered across the front and rear axles for full-width overlap coverage, and the operator sits under an open ROPS canopy. A dual-tank spray/wetting system feeds water to the tires to control asphalt pickup. A confirmed production-year window, a specific predecessor, and a direct successor model for this exact S/N 2001-UP block are not established in available documentation.
Because the 3D78AE runs mechanical fuel injection rather than an electronically controlled system, the JW30-2 has no OEM diagnostic fault codes to reference - service relies on mechanical inspection, oil analysis, and OMM-scheduled intervals rather than a dealer scan tool. That keeps the machine straightforward to service in the field, but it also means wear such as injection-timing drift, hydraulic seal leakage, or wetting-system deterioration shows up gradually rather than as a warning light. In today's used and parts market, the JW30-2 represents a legacy small pneumatic roller: demand and part availability lean toward used and reconditioned engine components, tires, and wetting-system hardware rather than new-production OEM stock, and buyers should verify capacities and any generation-specific parts against the actual serial number rather than assuming shared specification with other JW-family or similarly numbered Komatsu machines.
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 JW30-2(S/N 2001-UP) specifications
Engine
| Engine model | 3D78AE, 3-cylinder diesel |
| Gross power | 16.0 kW (21.4 hp) at 2,400 rpm |
| Displacement | 1.20 L (73.5 cu in) |
| Cylinders | 3 |
| Emissions tier | Not documented for this serial range; mechanical, pre-Tier engine of its era |
Weights
| Operating weight (standard) | 3,000 kg (6,614 lb) |
| Average weight per wheel (standard) | 375 kg (827 lb) |
| Ballasted/water-filled weight | Not documented for this exact serial range - verify with your dealer; many pneumatic rollers of this class offer heavier ballasted configurations |
Dimensions
| Overall width | 1.31 m (4.3 ft) |
| Overall height (to ROPS) | 1.74 m (5.7 ft) |
| Wheelbase | 1.92 m (6.2-6.3 ft) |
| Ground clearance | 0.21 m (0.7 ft) |
| Compaction/rolling width | approx. 1,300 mm (51 in) |
| Overall length | Not reliably documented - published figures conflict/appear truncated; verify with factory spec sheet |
Performance
| Maximum travel speed | 13.0 km/h (8.1 mph) |
| Tire configuration | Pneumatic tires in a staggered front/rear arrangement for full-width coverage; total wheel count is reported as 7 in some listings and 8 in spec-chart sources - verify against the dataplate |
| Standard tire size | 9.50/65 series pneumatic tire; exact ply rating and rim size vary by listing - confirm against the sidewall marking |
| Gradeability | Not published |
Service capacities (summary)
| Fuel tank | 36.3 L (9.6 gal) |
| Hydraulic system | Not documented in available sources - verify with your dealer |
| Engine oil | Not documented in available sources - verify with your dealer |
| Cooling system | Not documented in available sources - verify with your dealer |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
JW30-2(S/N 2001-UP) fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter), 3D78AE 3-cylinder diesel | not documented for this exact serial range in available sources — verify with your dealer | Komatsu EO series diesel engine oil; grade selected by ambient temperature per the standard Komatsu viscosity chart (10W-30 in temperate range, 30 in warmer climates, 0W-20/10W in cold climates) |
| Cooling system | not documented for this exact serial range in available sources — verify with your dealer | Komatsu AF-NAC (Super Coolant) or equivalent ethylene-glycol antifreeze/coolant, mixed to local climate minimum-temperature requirement |
| Fuel tank | 36.3 L (9.6 US gal) | Diesel fuel, low-sulfur, grade selected by ambient temperature (No. 2-D in warm weather, No. 1-D in cold weather, per standard practice) |
| Hydraulic system (drive/steering circuit) | not documented for this exact serial range in available sources — verify with your dealer | Komatsu HO series hydraulic oil (or TO series where the OMM specifies a shared hydraulic/powertrain fluid), viscosity graded to ambient temperature |
| Water tank (tire-wetting spray system) | not documented for this exact serial range in available sources — verify with your dealer; JW30-series rollers carry a spray-pump water system with dual tanks | Clean water; add a compatible anti-freeze agent for below-freezing operation per the OMM's cold-weather note |
| Grease points (roller drums/wheel bearings, linkages) | per fitting, no reservoir volume specified | Komatsu multipurpose lithium-based grease (Komatsu Grease series), NLGI grade per ambient temperature |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Komatsu JW30-2(S/N 2001-UP) maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 50 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 4,000 h |
|
Servicing the JW30-2(S/N 2001-UP) beyond the schedule
Predictive Maintenance & Fluid Analysis
With no ECM or fault-code readout on the 3D78AE, condition monitoring on the JW30-2 leans on scheduled oil sampling and physical inspection rather than telematics. Send engine oil for analysis at each scheduled drain to catch injection-pump wear before it surfaces as hard starting or smoke. Track hydraulic drive and steering oil condition for water intrusion from the tire-wetting spray system, and log tire pressure across all seven wheels to catch slow leaks before they skew compaction uniformity.
Corrective & Common Repairs
Typical JW30-2 repairs center on the wetting/spray system - clogged nozzles and worn spray-pump seals from mineral buildup in the dual water tanks are the most common callback. Expect periodic tie-rod and steering-linkage wear from the oscillating axle absorbing uneven ground, plus staggered-tire replacement as the pneumatic tires pick up asphalt aggregate and lose tread. On the 3D78AE, injection-pump and injector service is the recurring fix once the mechanical system drifts out of calibration, showing up as rough idle or exhaust smoke.
Overhaul & Rebuild Points
Major rebuild work on the JW30-2 concentrates on the 3D78AE's top end - injection-pump recalibration, injector reconditioning, and valve or cylinder-head service once compression or fuel economy fall off. On the chassis side, the hydraulic drive motor and power-steering pump are the wear items behind a full rebuild at higher hours, alongside the axle oscillation pins and bushings carrying the machine's rocking motion over uneven grade. Inspect the ROPS canopy mounts and frame welds for fatigue on older, hard-worked units before returning the roller to service.
Seasonal & Environment Servicing
Before winter layup or cold-weather work, drain the tire-wetting system's dual water tanks and spray lines to prevent freeze cracking, or dose them with a compatible anti-freeze agent. Check coolant concentration on the 3D78AE ahead of temperature swings, and re-check tire pressure as ambient temperature drops, since pneumatic tire pressure trends down in cold weather. In hot, dusty asphalt-season conditions, service the fuel filter more often for water and sediment, and keep the open ROPS canopy's engine air intake clear of aggregate dust.
JW30-2(S/N 2001-UP) common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| YM119833-55620 | 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 → |
| 257-80-17300 | Filter Ass'Y,Hydraulic Oil | Hydraulic service | Check fitment → |
| 258-81-25400 | Filter Ass'Y | Scheduled service item | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
JW30-2(S/N 2001-UP) fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| No electronic fault code system | The JW30-2 (S/N 2001-UP) uses a mechanical fuel-injection diesel with no engine control module and no diagnostic display, so it does not generate CID/FMI or Komatsu monitor error codes. | Not applicable — mechanical-era engine and roller controls have no onboard diagnostics to fault. | Diagnose by mechanical symptom and gauge/warning-lamp readings rather than by code lookup; use the shop manual troubleshooting tables for this engine range. |
| Charge/alternator lamp ON | Battery not charging. | Worn or slipping fan/alternator belt, faulty alternator, loose or corroded wiring connection. | Check belt tension and condition, check wiring and connections, test alternator output; replace as needed. |
| Engine oil pressure lamp ON | Low engine oil pressure. | Low oil level, worn oil pump, clogged oil filter, faulty pressure sender/switch. | Stop engine immediately, check oil level and condition, inspect filter, verify sender before restarting. |
| Coolant temperature gauge in red / overheat lamp ON | Engine coolant overheating. | Low coolant level, clogged radiator fins, slipping fan belt, faulty thermostat, failed water pump. | Stop and idle engine, let it cool, check coolant level and radiator for debris, inspect belt and thermostat. |
| Hard or no start | Engine fails to start or starts with difficulty. | Air in fuel system, clogged fuel filter, weak battery, worn glow plugs/starter, injection pump timing off. | Bleed fuel system, check battery state and connections, inspect fuel filter and glow plug circuit, verify starter operation. |
| Low power / black or white smoke | Engine runs but lacks power, or exhaust smoke is abnormal. | Dirty air filter, clogged fuel filter, injector wear, incorrect injection timing, low compression. | Check and clean/replace air and fuel filters, inspect injectors, check compression and injection timing per shop manual. |
| Excessive vibration or drum/wheel roll irregularity | Rolling or vibration system not performing to spec (on models with vibratory option). | Worn drive belt, low hydraulic fluid, worn bearings, tire pressure imbalance across the pneumatic wheel set. | Check hydraulic fluid level, inspect belts and bearings, verify and equalize tire pressures across all wheels. |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
JW30-2(S/N 2001-UP) attachments & work tools
Machine type / work-tool scope
JW30-2 is a self-propelled pneumatic (rubber-tired) roller in the roughly 3,000 kg operating class, built for asphalt finish and soil/base compaction. It is not an excavator or loader base machine, so it does not take digging buckets, breakers, or quick-coupler-mounted work tools; its "attachments" are compaction-support accessories only.
Tire / wheel arrangement
Fitted with smooth-tread pneumatic tires arranged in a staggered front/rear pattern so the wheel tracks overlap for full-width coverage in one pass. Reported tire counts for this class vary by source (around 7 to 9 wheels total) and standard tire size is quoted near 9.50/65-16, 6-ply rating; verify exact count and size against the machine's dataplate.
Water ballast system
Operating weight can be increased by filling the wheel/frame ballast with water, raising compaction force above the dry operating weight. For this size class wet-ballasted weight runs up to roughly 3,300 kg depending on fill level; treat the exact figure as varying by configuration.
Tire wetting / sprinkler system
A water tank feeds spray bars mounted front and rear to keep tire tread wet during operation. This prevents hot-mix asphalt from picking up on the tires during finish rolling and is standard equipment for this roller class.
Operator guarding / ROPS canopy
Standard configuration is an open operator station with a ROPS canopy overhead guard rather than an enclosed cab. No factory cab option is documented for this model in available records.
Scraper bars
Scraper bars that ride against the tire faces to strip off adhering material are a common accessory on pneumatic tire rollers of this size class, working alongside the tire wetting system. Fitment specifically on the JW30-2 is not independently documented in available sources — confirm with a dealer or the parts book for the actual serial range.
All JW30-2(S/N 2001-UP) assemblies by section
Every catalogued assembly group for the Komatsu JW30-2(S/N 2001-UP). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
3d78ae-3b Engine S/N 00101-Up
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Air Cleaner And Mounting
| YM***41 | Buffle | 1 |
| YM***10 | Support | 1 |
| YM***70 | Seat,Rubber | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Air Intake Manifold And Connection
| YM***01 | Heater,Intake Air | 1 |
| YM***52 | Screw | 4 |
| YM***00 | Clamp | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Alternator (40a)
| YM***50 | Brush Ass'Y | 1 |
| YM***00 | Retainer,Bearing | 1 |
| YM***70 | Diode Ass'Y | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Alternator And Mounting (40a)
| YM***30 | Plate,Adjust | 1 |
| YM***02 | Nut | 1 |
| YM***50 | Bolt | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Camshaft And Tappet
| YM***01 | Gear Ass'Y,Camshaft | 1 |
| YM***00 | Rod,Push | 6 |
| YM***50 | Bearing, Thrust | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Crankshaft
| YM***00 | Gear,Crank | 1 |
| YM***80 | Parallel Pin | 1 |
| YM***50 | Pulley,Crank | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Cylinder Block
| YM***00 | O-Ring (Kit) | 2 |
| YM***30 | Thrust Metal Ass'Y (Std) | 2 |
| YM***20 | Plug,Drain(Without Oil Cooler Type) | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Cylinder Head
| YM***80 | Retainer, Spring | 6 |
| YM***00 | Guide,Valve? Exhaust | 6 |
| YM***00 | Plug | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Cylinder Head Cover
| YM***20 | Cover, Breather | 1 |
| YM***50 | Cover Ass'Y,Head | 1 |
| YM***51 | Cap, Lub. Oil Supply | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Engine Stop Motor
| YM***80 | Ring,Snap | 1 |
| YM***00 | Pin,Cotter | 1 |
| YM***10 | Bracket | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Exhaust Manifold And Muffler
| YM***62 | Bolt | 2 |
| YM***02 | Stud | 1 |
| YM***80 | Collar | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Flywheel And Flywheel Housing
| YM***50 | Oil Seal Case, Assembly | 1 |
| YM***80 | Seal? Rear | 1 |
| YM***02 | Screw | 6 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Front Cover And Gear
| YM***90 | Front Cover Ass'Y | 1 |
| YM***51 | Cap, Lub. Oil Supply | 1 |
| YM***52 | Bolt | 4 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Fuel Filter And Piping
| YM***70 | Union | 1 |
| YM***40 | Lever | 1 |
| YM***00 | Hose | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Fuel Injection Pump (Governor) (1/2)
| YM***02 | Lever Ass'Y,Stop | 1 |
| YM***10 | Pin,Stop Lever | 1 |
| YM***00 | O-Ring (Kit) | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Fuel Injection Pump (Governor) (2/2)
| YM***01 | Weight Assembly., Governor | 1 |
| YM***90 | Shaft,Governor Lever | 1 |
| YM***16 | Pin,Spring | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Fuel Injection Pump (Pump) (1/2)
| YM***50 | Kit, Shim | 1 |
| YM***10 | Plate? Caution | 1 |
| YM***50 | Cover,Side | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Fuel Injection Pump (Pump) (2/2)
| YM***70 | Retainer, Spring | 3 |
| YM***00 | Plunger W/Barrel | 3 |
| YM***02 | Screw | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Fuel Injection Pump And Piping
| YM***20 | Retainer, Pipe | 1 |
| YM***60 | O-Ring,Fuel Injection Pump | 1 |
| YM***20 | Pipe,Injection? No.2 | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Fuel Nozzle And Spill Pipe
| YM***20 | Spring | 1 |
| YM***00 | Fuel Injection Nozzle, Assembly | 1 |
| YM***80 | Pipe | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Gasket Kit
| YM***60 | O-Ring,Fuel Injection Pump | 1 |
| YM***40 | O-Ring,Drain Plug | 1 |
| YM***10 | Gasket,Exhaust Manifold | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Lubricating Oil Filter
| YM***50 | Nut | 1 |
| YM***00 | Valve,Relief | 1 |
| YM***02 | Bolt Plated | 3 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Lubricating Oil Pump And Piping
| YM***50 | Oil Pressure Transmitter | 1 |
| YM***50 | Oil Pressure Transmitter | 1 |
| YM***02 | Seal,Ring (Kit) | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Oil Pan
| YM***30 | Hose,Drain | 1 |
| YM***00 | Gasket | 2 |
| YM***00 | Bolt,Joint | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : P.P.C. Pump And Mounting
| YM***70 | Pin | 2 |
| YM***02 | Screw | 3 |
| YM***20 | Clip | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Piston And Connecting Rod
| YM***50 | Ring Set (+0.25 mm) | 1 |
| YM***00 | Connecting Rod, Assembly | 3 |
| YM***00 | Screw | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Rocker Arm
| YM***50 | Rocker Arm Ass'Y | 6 |
| YM***02 | Screw | 6 |
| YM***80 | Spring | 3 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Safety Relay? Diode And Glow Plug Timer
| YM***00 | Diode | 1 |
| YM***00 | Relay, Safety | 1 |
| YM***20 | Timer,Ribbon Heater | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Starting Motor (2kw)
| YM***50 | Pinion Ass'Y,Pinion | 1 |
| YM***20 | Housing,Center | 1 |
| YM***40 | Field Coil Ass'Y | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Starting Motor And Mounting (2kw)
| YM***52 | Bolt Plated | 2 |
| (Y***1) | Starting Motor Ass'Y,(See Fig.A6210-B0a1) | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Tool
| YM***60 | Wrench,Fuel Filter? Water Separator | 1 |
| YM***70 | Wrench | 1 |
| YM***20 | Wrench | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : 3d78ae-3b Engine S/N 00101-Up : Water Pump And Cooling Fan
| YM***02 | Bolt Plated | 2 |
| YM***60 | Spacer | 1 |
| YM***20 | O-Ring,(Not Shown) | 1 |
Engine Related Parts And Electrical System
Komatsu : Jw30-2(S/N 2001-Up) : Engine Related Parts And Electrical System : Electrical System (1/3) (Relay And Front Line)
| 01***20 | Bolt,(Without Maintenance Monitor) | 4 |
| 01***16 | Bolt (With Air Heater & Conditioner) | 2 |
| 01***20 | Bolt,(With Auto Emergency Steering) | 4 |
Komatsu : Jw30-2(S/N 2001-Up) : Engine Related Parts And Electrical System : Electrical System (2/3) (Monitor Panel)
| 25***00 | Switch,Water Splinkler | 2 |
| 25***12 | Panel,Monitor | 1 |
| 25***60 | Switch,Brake | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Engine Related Parts And Electrical System : Electrical System (3/3) (Battery And Rear Line)
| 01***20 | Bolt, Wiring Harness Mounting Bracket | 4 |
| 01***16 | Screw, Mount Parking Lights | 2 |
| 01***04 | Nut,(For Air Conditioner Less) | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Engine Related Parts And Electrical System : Engine Mounting Parts And Hst Pump
| 01***20 | Bolt,(With Auto Emergency Steering) | 2 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 6 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Engine Related Parts And Electrical System : Exhaust Related Parts
| 01***25 | Bolt,Without Revolution Sensor | 2 |
| 01***65 | Bolt,R.H | 1 |
| 01***70 | Bolt (Op) | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Engine Related Parts And Electrical System : Fuel Tank(#2001-2085)
| 01***14 | Screw | 5 |
| 01***13 | Washer,Spring(For Wiper Switch Earth) | 5 |
| 25***23 | Cap | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Engine Related Parts And Electrical System : Fuel Tank(#2086-)
Komatsu : Jw30-2(S/N 2001-Up) : Engine Related Parts And Electrical System : Radiator And Mounting Parts
| 01***12 | Bolt,(With Cylinder Cover) | 8 |
| 01***16 | Bolt (With Air Heater & Conditioner) | 2 |
| 01***06 | Nut,(With Back-Up Alarm) (Op), Nut; Was 01580-10806 | 8 |
Frame And Body
Komatsu : Jw30-2(S/N 2001-Up) : Frame And Body : Bonnet And Tank Cover(#2001-2040)
| 01***20 | Bolt,(Without Air Con. Or Heater) | 2 |
| 01***20 | Bolt, Wiring Harness Mounting Bracket | 2 |
| 01***20 | Bolt,(For Mono Lever Steering) | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Frame And Body : Bonnet And Tank Cover(#2041-)
| 01***20 | Bolt, Wiring Harness Mounting Bracket | 2 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 6 |
| 01***30 | Bolt,(Not Used When Towing Winch) | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Frame And Body : Dashboard
| 01***20 | Bolt,(Without Maintenance Monitor) | 4 |
| 01***16 | Bolt (With Air Heater & Conditioner) | 8 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 4 |
Komatsu : Jw30-2(S/N 2001-Up) : Frame And Body : Main Frame And Cover
| 01***16 | Bolt (With Air Heater & Conditioner) | 8 |
| 01***20 | Bolt,(With Auto Emergency Steering) | 4 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Frame And Body : Operator'S Seat
| 01***20 | Bolt,(With Auto Emergency Steering) | 8 |
| 01***35 | Bolt,(For Quick Shift) (Mitsubishi) | 8 |
| 01***06 | Nut,(With Back-Up Alarm) (Op), Nut; Was 01580-10806 | 10 |
Komatsu : Jw30-2(S/N 2001-Up) : Frame And Body : Steering Yoke
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 2 |
| 01***25 | Bolt,(Without Rops Guard? Canopy) | 4 |
| 01***40 | Bolt,(With Service Valve R.H.) | 4 |
Mark Plate And Tool
Komatsu : Jw30-2(S/N 2001-Up) : Mark Plate And Tool : Marks And Plates (English)(#2086-)
| 09***21 | Plate? Caution,Fuel Inlet | 1 |
| 09***10 | Plate? Safety,Hydraulic Tank Cap | 1 |
| 09***01 | Plate? Caution,Radiator | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Mark Plate And Tool : Tool
| 07***00 | Pump,Grease | 1 |
| 07***04 | Cartridge,Grease | 1 |
| 07***00 | Nozzle,(For Rubber Shoe) | 1 |
Steering And Control Systems
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Barke Cylinder And Mounting Parts
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 1 |
| 01***16 | Nut (Op) | 2 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Brake Pedal And Linkage
| 01***20 | Bolt,(With Auto Emergency Steering) | 2 |
| 01***25 | Bolt,Without Revolution Sensor | 2 |
| 01***30 | Bolt,(For Mechanical Governor) | 3 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Forward And Reverse Control Lever
| 01***16 | Bolt (With Air Heater & Conditioner) | 4 |
| 01***20 | Bolt,(With Auto Emergency Steering) | 11 |
| 01***30 | Bolt,(Not Used With Emergency Str.) | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Fuel Control Lever
| 01***16 | Bolt (With Air Heater & Conditioner) | 4 |
| 01***50 | Bolt,(Shim Thickness?Less Than 8mm) | 1 |
| 01***25 | Screw | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : High And Low Speed Control Linkage
| 01***16 | Bolt (With Air Heater & Conditioner) | 2 |
| 01***06 | Nut,(With Back-Up Alarm) (Op), Nut; Was 01580-10806 | 2 |
| 01***25 | Washer,Spring?For Additional Rear Lam | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Steering Cylinder
| 07***65 | O-Ring,Injection Pump Case | 1 |
| 07***60 | O-Ring,(F4350-59a0 -6 ) | 1 |
| 07***26 | Nut, Nylon | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Steering Cylinder Mounting Parts
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 2 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 2 |
| 04***18 | Ring, Snap | 4 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Steering Piping (1/5) (Suction Line)
| 01***16 | Bolt (With Air Heater & Conditioner) | 6 |
| 01***20 | Screw | 3 |
| 01***19 | Washer,Spring (With Extinguisher) (D31p) | 3 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Steering Piping (2/5) (Delivery Line)
| 01***20 | Screw | 3 |
| 01***19 | Washer,Spring (With Extinguisher) (D31p) | 3 |
| 25***23 | Elbow | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Steering Piping (3/5) (Cylinder Line)
| 07***14 | O-Ring,(F4350-61a0a-20 ) | 1 |
| 25***23 | Elbow | 1 |
| 25***13 | Elbow | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Steering Piping (4/5) (Return Line)
| 07***20 | O-Ring,Relief Valve | 1 |
| 25***23 | Adapter | 1 |
| 25***50 | Bushing | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Steering Piping (5/5) (Drain Line)
| 07***20 | O-Ring,Relief Valve | 1 |
| 25***23 | Elbow | 1 |
| 25***50 | Bushing | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Steering Valve (Inner Parts)
| 25***00 | Control Ass'Y | 1 |
| 25***10 | Spring | 1 |
| 25***00 | Plug Ass'Y | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Steering And Control Systems : Steering Wheel
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 4 |
| 01***35 | Bolt,(For Quick Shift) (Mitsubishi) | 4 |
| 01***11 | Nut - Mounting | 1 |
Tire And Brake
Komatsu : Jw30-2(S/N 2001-Up) : Tire And Brake : Front Wheel
| 01***30 | Bolt,(Not Used When Towing Winch) | 4 |
| 01***50 | Bolt,(For Large Size Tire) | 8 |
| 01***60 | Washer,(For Large Size Tire) | 8 |
Komatsu : Jw30-2(S/N 2001-Up) : Tire And Brake : Rear Wheel
| 01***25 | Bolt,(Without Rops Guard? Canopy) | 4 |
| 01***70 | Bolt, Accumulator Mounting Bracket | 4 |
| 01***36 | Washer,Spring | 4 |
Komatsu : Jw30-2(S/N 2001-Up) : Tire And Brake : Travel Motor And Chain
| 01***35 | Bolt, Mount Ground Driven Steering Pump | 6 |
| 01***45 | Bolt, Mounting Cranking Motor | 4 |
| 01***40 | Bolt,(For Slag Handling) (For Usa) | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Tire And Brake : Wheel Brake
| 01***35 | Bolt,(With Rops) | 4 |
| 01***45 | Bolt,(For 60ton Dump Body) | 2 |
| 01***48 | Washer,Spring (For Slag Handling), Washer-Spring | 6 |
Water Spray System And Hydraulic Piping
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Hst Pump (1/2)
| 25***00 | Pump Ass'Y,Hst | 1 |
| 25***10 | Housing | 1 |
| 25***20 | Seal | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Hst Pump (2/2)
| 25***00 | Seal Kit | 1 |
| 25***70 | Housing | 1 |
| 25***80 | Spacer | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Hydarulic Piping (Brake Cylinder Line)
| 25***12 | Elbow | 2 |
| 25***22 | Elbow | 1 |
| 26***02 | Nipple | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Hydraulic Oil Tank
| 01***16 | Bolt (With Air Heater & Conditioner) | 10 |
| 01***25 | Bolt,(For Canvas Canopy?Head Guard) | 2 |
| 01***45 | Bolt,(For Power Tilt Mech Angle) | 4 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Hydraulic Piping (Brake Valve Line)
| 01***90 | Bolt, Priority Valve Mounting | 3 |
| 01***06 | Nut,(With Back-Up Alarm) (Op), Nut; Was 01580-10806 | 3 |
| 01***25 | Washer,Spring?For Additional Rear Lam | 3 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Hydraulic Piping (Bypass Valve Line)
| 01***16 | Bolt (With Air Heater & Conditioner) | 2 |
| 01***20 | Bolt,(With Auto Emergency Steering) | 2 |
| 01***06 | Nut,(With Back-Up Alarm) (Op), Nut; Was 01580-10806 | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Hydraulic Piping (Hst Pump Line)
| 07***26 | Clamp,Hose | 2 |
| 25***00 | Filter Ass'Y,Hydraulic Oil | 1 |
| 25***10 | Element Ass'Y | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Hydraulic Piping (Travel Motor Line)
| 25***20 | Elbow | 1 |
| 25***40 | Hose | 2 |
| 25***14 | Elbow | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Oil Spray Piping (1/4) (Suction Line)(#2001-2085)
| 01***20 | Bolt, Wiring Harness Mounting Bracket | 2 |
| 01***16 | Screw,(P.O.C. Model) (Except Japan) | 4 |
| 01***19 | Washer,Spring (With Extinguisher) (D31p) | 4 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Oil Spray Piping (1/4) (Suction Line)(#2086-)
| 01***20 | Bolt, Wiring Harness Mounting Bracket | 2 |
| 01***16 | Screw,(P.O.C. Model) (Except Japan) | 4 |
| 01***19 | Washer,Spring (With Extinguisher) (D31p) | 4 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Oil Spray Piping (2/4) (Delivery Line)
| 07***37 | Clamp | 2 |
| 07***00 | Tee | 2 |
| 07***00 | Nipple | 3 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Oil Spray Piping (3/4) (Front Nozzle Line)
| 01***25 | Bolt,Without Revolution Sensor | 2 |
| 01***06 | Nut,(With Back-Up Alarm) (Op), Nut; Was 01580-10806 | 2 |
| 01***25 | Washer,Spring?For Additional Rear Lam | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Oil Spray Piping (4/4) (Rear Nozzle Line)
| 01***20 | Bolt,(With Auto Emergency Steering) | 1 |
| 01***25 | Bolt,Without Revolution Sensor | 1 |
| 01***11 | Nut,(With Under Mirror) | 4 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Travel Motor
| 25***00 | Motor | 1 |
| 25***50 | Seal,Oil (Kit) | 1 |
| 25***60 | O-Ring (Kit) | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Water Filter
| 27***00 | Filter Ass'Y,Water | 1 |
| 27***20 | Case | 1 |
| 27***80 | O-Ring | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Water Pump
| 07***00 | O-Ring,(F4350-65a1 -5 ) | 1 |
| 25***00 | Pump Ass'Y,Water | 1 |
| 25***70 | Casing | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Water Spray Piping (1/5) (Suction Line)
| 01***12 | Bolt,(With Cylinder Cover) | 4 |
| 01***25 | Washer,Spring?For Additional Rear Lam | 4 |
| 07***59 | Clamp | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Water Spray Piping (2/5) (Delivery Line)
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 2 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 2 |
| 07***59 | Clamp | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Water Spray Piping (3/5) (Front Nozzle Line)
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 2 |
| 01***30 | Washer, Spring (Supplied W/Spider Assembly), Washer-Spring | 2 |
| 07***97 | Clamp | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Water Spray Piping (4/5) (Rear Nozzle Line)
| 01***11 | Nut,(With Under Mirror) | 4 |
| 07***97 | Clamp | 2 |
| 07***42 | Clip,(With Under Mirror) | 2 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Water Spray Piping (5/5) (Drain Line)
| 07***97 | Clamp | 2 |
| 07***00 | Elbow | 1 |
| 07***00 | Nipple | 1 |
Komatsu : Jw30-2(S/N 2001-Up) : Water Spray System And Hydraulic Piping : Water Tank
| 01***16 | Bolt, Mount Washer Tank To Bracket, Bolt | 4 |
| 01***20 | Bolt,(For Quick Shift) (Mitsubishi) | 2 |
| 01***20 | Bolt | 12 |
JW30-2(S/N 2001-UP) serial number reference
The PIN/serial plate on this roller is mounted on the frame near the operator platform or on the front chassis rail, stamped with the full machine designation (e.g. JW30-2) followed by the sequential unit number. This roller line does not use a separate multi-character regional or generation prefix ahead of the number - the model code itself is the prefix, and the digits after it are the running serial (real-world units are seen in the form JW30-2 followed by a 4-digit running number), so read S/N 2001 and up as the start of this production block.
| Prefix | Identifies | Notes |
|---|---|---|
| JW30-2 | Base 7-wheel pneumatic (rubber-tired) roller, S/N 2001-UP | Single confirmed serial block for this machine; no sub-prefixes or plant/region codes found tied to this range. Engine fitted is the 3-cylinder 3D78AE diesel, about 16 kW (21 hp) class at 2400 rpm. Operating weight about 3,000 kg (6,614 lb). Compaction width about 1300 mm (4.3 ft), open operator station, staggered pneumatic tires front and rear (exact size and wheel count vary by listing - confirm against the dataplate). The 3D78AE block is commonly cross-referenced in the parts trade to the Yanmar 3TNE78 engine family, but this manufacturer lineage is not documented in factory literature for this serial range - treat as unconfirmed. Confirm with dealer for any mid-run running changes inside the 2001-UP block. |
Frequently asked questions
What engine powers the Komatsu JW30-2 (S/N 2001-UP)?
A Komatsu 3D78AE three-cylinder, water-cooled diesel producing about 16 kW (21-22 hp) at 2,400 rpm from 1.20 L displacement. It uses mechanical fuel injection with no electronic engine controls or fault-code system.
What is the operating weight of the JW30-2 (S/N 2001-UP)?
Approximately 3,000 kg (6,600 lb) in standard configuration, with roughly 375 kg (827 lb) average weight per wheel. Ballasted/water-filled weight is not documented for this exact serial range - confirm with your dealer if working near a load limit.
What replaced the Komatsu JW30-2?
No confirmed direct successor model is documented in available sources for this exact S/N 2001-UP block. Treat any claimed replacement model with caution and verify current availability and cross-reference through a Komatsu dealer.
What JW30-2(S/N 2001-UP) owners discuss
How does the hydraulic drive and steering feel on the JW30-2, and what's a common complaint?
This roller runs a hydraulic (hydrostatic) drive with power steering, typical for a small pneumatic finish roller of this class. Operators of this size machine commonly report a slow forward creep when the travel pedal or lever is released to neutral. On this class of hydrostatic drive that's usually traced to worn or gummed-up linkage bushings, a weak centering spring/damper on the pedal or lever assembly, or a neutral position that has drifted out of adjustment over time rather than a failed pump. Cleaning and lubricating the linkage and re-centering the neutral stop resolves most cases. Have your dealer verify pump and charge pressure if creep persists after linkage service, since that points to internal pump wear instead.
What wear pattern should I expect on the tires and rolling gear, and is wobble normal?
The JW30-2 uses a staggered 7-wheel layout, one axle carrying one wheel fewer than the other, so the wheel tracks overlap and no single tire repeats the same line twice. That design is meant to erase lap marks and even out compaction, and it works as intended when tire pressures are matched across all wheels. Uneven pressure between tires is the most common cause of an inconsistent finish and accelerated tread wear on one side. Any noticeable wheel wobble on turns is not normal for this design and usually means worn oscillating-axle bushings or pins rather than a tire problem; have that checked before it scuffs the finished surface.
Are there known quirks with the 3D78AE engine, especially in cold weather?
The 3D78AE is a small 3-cylinder water-cooled diesel rated around 16 kW (22 PS) at 2,400 rpm, and parts cross-references tie it to the same small industrial diesel family used across several other badges of this displacement class -- treat any specific manufacturer lineage claim as unconfirmed unless your dealer's parts lookup confirms it for your serial. Engines in this class commonly rely on compression heat plus a cold-start aid (glow plug or thermostart element) rather than a heavy pre-heat system, so slow cranking or a no-start in cold weather is more often a weak battery, thick cold oil, or a tired cold-start aid than an injection problem. If the engine only struggles to start cold but runs fine once warm, that pattern points to the glow/thermostart circuit first.
What electrical or sensor issues come up most on this class of small roller?
Detailed fault-code or sensor documentation isn't published for this exact serial range -- this machine predates the ECM-driven diagnostics common on later equipment, so most electrical complaints on this class of roller are basic charging-circuit and safety-interlock issues rather than sensor faults. A charge/battery warning light that stays lit at idle but clears at higher rpm usually points to a weak or slipping alternator belt rather than the alternator itself. Seat or neutral-start safety switches on small compaction equipment are a common nuisance-fault point since they sit exposed to vibration, dirt, and moisture; a machine that won't crank or that dies unexpectedly is worth checking there before assuming a bigger electrical fault. Have your dealer verify wiring and switch continuity before replacing the alternator or starter.
Why does the water spray system clog, and how do operators prevent it?
Spray-bar and nozzle clogging is one of the most common complaints across pneumatic finish rollers generally, not unique to this model, because the tank draws in whatever debris rides along with the fill water. Clogging causes uneven wetting across the tires, which shows up as inconsistent pickup and streaking on the finished mat. Common practice is filling only with clean water through a screened cap, flushing the tank and lines regularly, and clearing the bar end caps of debris rather than waiting for a nozzle to fully block. If a blending additive is used, operators flush the system before any extended idle period so residue doesn't set up in the lines.
Is tire ballast adjustment relevant on a roller this size, and what should I watch for?
Pneumatic rollers in general rely on ballast (water, sand, or weighted fill in the tire or wheel compartments) to fine-tune compaction load beyond the machine's base operating weight, and this small class of finish roller is no exception. The compartments should be inspected for the correct ballast type and level, since uneven or missing ballast between wheels defeats the staggered-tire design and produces an inconsistent finish even with correct tire pressures. Tire pressure and ballast should always be checked together, not independently, since one masks problems with the other.
What should I check before buying a used JW30-2?
Check tread depth and cracking on all tires and confirm pressures are even and consistent across every wheel; mismatched pressure or wobble on turns points to worn oscillating-axle bushings or pins. Inspect the ballast compartments for correct fill and look for water staining that suggests a leaking or overfilled tank. Look for hydraulic leaks at the drive motors, steering cylinders, and hoses, and cycle the steering fully both directions to feel for binding. Confirm the engine starts cleanly from cold without excessive smoke, and watch the charge warning light behavior at idle versus higher rpm. Test the water spray system for even flow across the full width of the bar, not just at the ends. Because documented service history and fault records are thin for this exact serial range on the used market, a cold start and full operating cycle with a dealer or qualified mechanic present is worth more than any spec sheet comparison.
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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