0445120236
0445120236 Injector: Cummins QSL9 Komatsu PC300 Specs
3965721, 3973060, 4939061, 4940170, 5263308, 6745113102, 6745123100, 84346812F00RJ01941DLLA118P22031600 barProduct Overview
The Bosch 0445120236 common rail diesel injector is an original equipment CRIN2 solenoid-actuated injector engineered for heavy commercial, industrial, and off-highway applications powered by the 8.9-liter Cummins QSL9 and Komatsu SAA6D114E-3 six-cylinder engines. Operating at operating injection pressures up to 1600 bar, this unit integrates a Bosch DLLA118P2203 hole-type nozzle (Bosch part number 0433172203) alongside a precision F00RJ01941 control valve set to deliver high-pressure atomization across demanding duty cycles. Used extensively across Komatsu PC300-8 and PC350-8 excavators as well as Case construction machinery, the 0445120236 ensures Tier 3 and Stage IIIA emissions compliance. Typical field failures stem from fuel contamination, abrasive particulate ingress, and internal valve seat erosion, resulting in excessive backleak flow, hard starting under hot conditions, black exhaust smoke, erratic engine idle, or low common rail pressure fault codes.
Before installation, confirm cross-references against Cummins OE 5263308, Case 84346812, or Komatsu 6745-12-3100; this CRIN2 heavy-duty injector does not require IMA coding but always replace the fuel feed connector tube and nozzle copper crush washer.
Vehicle & Engine Fitment
| Vehicle | Engine | Years |
|---|---|---|
| Komatsu PC300-8 / PC350-8 / WA380-6 Excavator & Wheel Loader | Cummins QSL9 / ISLe 8.9L & Komatsu SAA6D114E-3 (8.9L) | 2006-2018 |
| Cummins QSL9 Industrial, Construction & Marine Power Unit | Cummins QSL9 / ISLe 8.9L & Komatsu SAA6D114E-3 (8.9L) | 2007-2018 |
| Case CX290B / CX350B Heavy Crawler Excavator | Cummins QSL9 / ISLe 8.9L & Komatsu SAA6D114E-3 (8.9L) | 2007-2017 |
| Case Axial-Flow 5088 / 6088 / 7088 Combine Harvester | Cummins QSL9 / ISLe 8.9L & Komatsu SAA6D114E-3 (8.9L) | 2008-2016 |
Technical Specifications
| Specification | Value |
|---|---|
| SKU | 0445120236 |
| Brand | Komatsu / Cummins / Case / BOSCH |
| Type | Complete Injector Assembly (Bosch Common Rail (CRIN2 solenoid)) |
| OE Number | 3965721, 3973060, 4939061, 4940170, 5263308, 6745113102, 6745123100, 84346812 |
| Control ValveCore Spec | |
| Nozzle CodeCore Spec | |
| Internal Nozzle P/NCore Spec | |
| Injection System | Bosch Common Rail (CRIN2 solenoid) |
| Operating PressureCore Spec | |
| Torque Spec | 35 N·m |
| Hold Down Torque | 30 N·m |
| Warranty | 12 Months |
| Emission Standard | Tier 3 / Stage IIIA |
| Engine Family | Cummins QSL9 / Komatsu SAA6D114E-3 (8.9L) |
| Coding Required | Verify with OEM tool |
| Magnet Assembly | F00RJ02697 |
| Seal Ring Kit | F00RJ02176 |
Installation Tips
Tools needed: 10mm & 11mm flare nut wrench (rail and injector inlet unions), Injector slide hammer / mechanical puller kit (if seized), Injector seat cleaning brass brush set & industrial vacuum, Seat reaming tool (if carbon erosion is present), Torque wrench (2 N·m - 40 N·m range), ECU diagnostic scan tool with IMA/QR coding capability, Digital micrometer / depth gauge for copper washer check
- Disconnect Battery & Relieve Rail Pressure: Isolate negative battery terminal and verify rail residual pressure drops below 10 bar via live diagnostics before cracking fuel fittings.
- Clean Engine Bay & Injector Recesses: Thoroughly blast away grit, oil slurry, and loose dirt around cylinder head injector wells using compressed air and degreasing solvent.
- Label Wiring Harness & Spill-Off Connectors: Tag each cylinder harness connector and gently disengage delicate plastic spill-off return rail clips.
- Remove High-Pressure Supply Lines: Back off high-pressure union nuts with a flare-nut wrench; IMMEDIATELY cap all open fuel rail orifices and injector inlets with clean blanking caps.
- Extract Hold-Down Clamp Fasteners: Back out hold-down clamp bolts. Note that torque-to-yield stretch bolts must always be discarded and never reused.
- Extract Injector Body: Withdraw injector vertically. If carbon-bonded or coked, attach an approved mechanical slide-hammer puller to the inlet adaptor without rotating the injector body.
- Inspect Injector Well & Bore: Ensure old copper seal washer has not remained fused at the base of the cylinder head seat; remove with a brass retrieval pick if stuck.
- Clean & Ream Injector Seat: Ream and burnish injector seating face using dedicated seat cutter brushes and industrial vacuum until seat is 100% bare, flat metal.
- Install New Copper Sealing Washer: Mount an OEM-specification copper washer of designated thickness (standard 1.5mm-2.0mm) using high-temp grease to hold in position.
- Fit Injector with Ceramic Anti-Seize: Lightly coat the injector body barrel with approved high-temperature ceramic grease; keep nozzle tip and copper washer strictly dry and clean.
- Torque Hold-Down Clamp to Spec: Secure hold-down clamp bolts and torque to factory specified stages (30 N·m) using a calibrated torque wrench.
- Refit High-Pressure Delivery Pipes: Thread union nuts by hand to avoid cross-threading, then tighten injector inlet and rail unions to 35 N·m evenly.
- Reconnect Return Leak-Off Line & Harness: Push on leak-off return clips until retaining collars click home; reattach electrical plug and lock harness tab firmly.
- ECU IMA / QR Code Calibration & Fuel Priming: Program the unique alphanumeric IMA/QR calibration code etched on the injector head into the corresponding ECU cylinder address; prime fuel system prior to initial cranking.
- CRITICAL IMA CALIBRATION: Never operate the engine without programming the new IMA/QR trim code into the ECU map — uncalibrated injectors cause combustion knocking, cylinder imbalance, and premature DPF clogging.
- CRITICAL COPPER WASHER REPLACEMENT: Always install brand new copper crush washers and torque-to-yield clamp bolts — reusing old seals leads to catastrophic combustion gas leakage ('black death' buildup).
- HOSPITAL-GRADE FUEL CLEANLINESS: A microscopic contamination particle as small as 5 microns can jam the internal F00RJ01941 valve or needle — ensure all fuel line plugs stay on until final connection.
- STRICT HOLD-DOWN TORQUE: Adhere strictly to the 30 N·m tightening sequence — overtightening distorts the injector body and binds the needle.
Frequently Asked Questions
Does Bosch injector 0445120236 require ECU coding (IMA / QR code)?
Yes, Bosch injector 0445120236 requires cylinder-specific IMA calibration code programming into the engine control unit (ECU). Each unit has a unique multi-character calibration code stamped on its electrical connector body or solenoid head that defines fuel delivery tolerances across multiple rail pressure points. Programming this code via a diagnostic scanner (Bosch KTS, VCDS, ODIS, INPA/ISTA, or Autel MaxiSys) is mandatory to ensure balanced cylinder idle, Tier 3 / Stage IIIA emissions compliance, and smooth throttle response.
What are the most common symptoms of a failing 0445120236 injector on Komatsu / Cummins / Case Cummins QSL9 / Komatsu SAA6D114E-3 (8.9L)?
Common symptoms include prolonged cold-start cranking, rough or oscillating idle, black exhaust smoke under acceleration (nozzle needle wear/over-fueling), white smoke on startup (unburnt fuel spray), ticking/clattering under load, increased fuel consumption, cylinder misfire trouble codes (P0201-P0206 / P0300-P0306), and high fuel spill-off return rates causing low rail pressure fault codes under heavy acceleration.
Should I replace injectors individually or as a complete set?
While replacing a single failed injector is acceptable if fuel contamination is ruled out, industry best practice on engines with over 150,000 km is to replace or bench-test all injectors as a complete set. Wear across the high-pressure control valve (F00RJ01941) and nozzle (DLLA118P2203) occurs evenly across all cylinders; fitting one new unit alongside worn units often leads to noticeable idle vibration due to delivery quantity variance.
Why must the copper crush washer and hold-down bolt be replaced on every install?
The copper washer forms the critical gas-tight seal between the injector nozzle and the cylinder head combustion chamber. During combustion, temperatures exceed 1,500°C and pressures surpass 150 bar. A compressed washer work-hardens and will not re-seal properly. Furthermore, most hold-down clamp bolts are torque-to-yield (stretch) fasteners designed for single use; reusing them risks bolt snapping inside the cylinder head or loss of clamp tension.
What preventative maintenance is required after installing replacement 0445120236 injectors?
Always replace the diesel fuel filter with a high-efficiency OEM-spec filter (3 to 5 micron rating), inspect the fuel tank and fuel lines for metallic swarf from high-pressure pump wear, flush the common rail if debris is present, use high-quality EN590 diesel, and verify injector smooth running balance values with diagnostic software after 500 km of driving.
Diagnostic Trouble Codes & Fault Protocols
Common diagnostic trouble codes (DTCs) triggered when this common rail injector experiences wear, circuit faults, or calibration drift:
Fuel Rail / System Pressure Too Low
Excessive internal backleak from worn control valve seats drops common rail pressure below target under engine load.
Injector Circuit Malfunction / Open Circuit
Solenoid coil resistance drift (0.2-0.5 Ω) or piezo stack degradation triggers driver stage shutdown on affected cylinders.
Cylinder Misfire & Balancing Deviation
Carbon-clogged nozzle spray holes or missing IMA calibration causes uneven cylinder contribution. Recode ECM and verify washer seating.
Fuel Rail / System Pressure Too High
Spill line backpressure or stuck metering valve prevents rail depressurization, creating overpressure risks under load.
Cross-Reference & Compatibility
Sister parts, same-platform variants, and known incompatibilities.
Technical Diagnostic & Service Protocols
Authoritative field procedures, diagnostic testing thresholds, and service SOPs for this assembly.