0445120231
BOSCH 0445120231 Common Rail Injector for Komatsu PC200-8 / Cummins QSB6.7
6754-11-3010, 6754-11-3011, 6754-11-3012, 6754113010, 6754113011, 6754113012, 3976372, 4945969, 5263262, 397637D, 5263314NXF00RJ02130DSLA128P55101600 barProduct Overview
The Bosch 0445120231 common rail diesel injector is an authentic original equipment CRIN2 heavy-duty solenoid injector engineered specifically for harsh construction and earthmoving machinery. Powered by the 6.7-liter Komatsu SAA6D107E-1 turbocharged diesel engine and industrial Cummins QSB6.7 / QSB4.5 power units, this component is the factory benchmark for the world-renowned Komatsu PC200-8, PC220-8, and PC270-8 hydraulic crawler excavators as well as WA200-6 and WA380-6 wheel loaders. Operating at high-pressure common rail injection pressures up to 1600 bar, the 0445120231 integrates a precision-engineered Bosch DSLA128P5510 8-hole spray nozzle (Bosch production part number 0433175510) and an ultra-durable F00RJ02130 high-pressure balanced control valve set. Driven by a dedicated heavy-duty solenoid magnet assembly F00RJ02697 and sealed by an industrial fluorocarbon seal ring kit F00RJ02176, this injector guarantees full compliance with Tier 3 and EU Stage IIIA off-highway emissions standards while maximizing hydraulic breakout force and fuel economy. In severe jobsite environments, heavy equipment fuel injectors face abrasive micro-particulate wear, water emulsification, and fuel thermal degradation. As the internal control valve ball and seat erode, dynamic return backleak flow surges beyond tolerance, triggering diagnostic trouble code P0087 (Rail Pressure Too Low During Cranking), prolonged starter engagement (hot-start cranking exceeding 8-10 seconds), rough engine idle, black exhaust soot under heavy hydraulic load, and unburned fuel dilution of engine crankcase oil. Replacing worn injectors with genuine 0445120231 units completely restores rail pressure stability, cold-weather responsiveness, and factory power output.
CRITICAL FIELD ADVISORY: The Bosch 0445120231 is the factory-reinforced successor to the earlier 0445120059 injector. When servicing Komatsu PC200-8 excavators, always install a brand-new fuel feed connector tube (Komatsu OE 6754-11-3111) alongside a 1.5mm copper crush washer. This industrial CRIN2 unit does NOT require IMA programming, but failure to follow the 3-step torque procedure will cause unmetered fuel leak-off into the valvetrain.
Vehicle & Engine Fitment
| Vehicle | Engine | Years |
|---|---|---|
| Komatsu PC200-8 / PC220-8 / PC270-8 Crawler Excavator | Cummins ISB / QSB 6.7L (ISDe / Komatsu SAA6D107E) | 2006-2017 |
| Komatsu WA200-6 / WA250-6 / WA380-6 Wheel Loader | Cummins ISB / QSB 6.7L (ISDe / Komatsu SAA6D107E) | 2006-2016 |
| Hitachi ZW180 / ZW180-PL Wheel Loader | Cummins ISB / QSB 6.7L (ISDe / Komatsu SAA6D107E) | 2007-2015 |
| Hyundai Robex R210LC-9 / HL770-7A Excavator & Loader | Cummins ISB / QSB 6.7L (ISDe / Komatsu SAA6D107E) | 2008-2016 |
Technical Specifications
| Specification | Value |
|---|---|
| Injector Part Number | 0445120231 |
| Manufacturer | BOSCH |
| Fuel System Type | Common Rail (CRIN2 Solenoid) |
| Operating Rail PressureCore Spec | |
| Nozzle Stamping CodeCore Spec | |
| Nozzle Order NumberCore Spec | |
| Control Valve SetCore Spec | |
| Magnet Assembly | F00RJ02697 |
| Seal Ring Kit | F00RJ02176 |
| High-Pressure Fitting Torque | 35 N·m |
| Injector Clamp Hold-Down Torque | 8 N·m + 90° TTY (approx. 30 N·m)📐 Torque & Angle Wizard → |
| Feed Connector Tube Nut Torque | 15 N·m preliminary / 50 N·m final |
| Coil Resistance at 20°C | 0.25 - 0.50 Ohms |
| ECU Compensation Coding | Not Required (CRIN2 Industrial Mechanical Calibration) |
| Emissions Certification | EPA Tier 3 / EU Stage IIIA Off-Highway |
| Compatible Predecessor | 0445120059 (Direct Drop-in Replacement) |
| Operating PressureCore Spec |
Installation Tips
- ### 1. The 3-Step Torque Procedure for Side-Feed Connector Tubes
- Komatsu SAA6D107E-1 and Cummins QSB6.7 engines utilize cross-cylinder fuel feed connector tubes (Komatsu OE 6754-11-3111) that deliver high-pressure fuel from the rail to the side port of the injector. The conical nose of the tube must crush into the injector side inlet port to create a leak-tight metal-to-metal seal at 1600 bar. Never torque the hold-down clamp before seating the connector tube!
- | Assembly Step | Target Component | Torque & Angle Specification | Critical Workshop Objective |
- | :--- | :--- | :--- | :--- |
- | Step 1: Snug Tube | Side Connector Tube Nut | 15 N·m (11 ft-lbs) | Self-aligns the spherical nose of the tube perfectly into the injector cone inlet without galling. |
- | Step 2: Clamp Preload | Injector Hold-Down Bolt | 8 N·m (71 in-lbs) + 90° TTY | Stretches the clamp bolt into its elastic yield zone; firmly seats the injector onto its copper washer. |
- | Step 3: Final Tube Lock | Side Connector Tube Nut | 50 N·m (37 ft-lbs) | Crushes the metal sealing taper into a 1600 bar zero-leakage hydraulic joint. |
- ### 2. High-Pressure Line & Fuel Fitting Fastening
- High-Pressure Rail Pipe Fittings: Tighten rail union nuts to 35 N·m (26 ft-lbs).
- Two-Wrench Counter-Torque Rule: Always hold the injector inlet fitting stationary with an open-ended wrench while tightening the fuel line union nut to prevent shearing the internal anti-rotation alignment pins.
- ### 3. Cylinder Head Bore Preparation & Copper Washer Sizing
- Seat Bore De-Carboning: Use a brass wire rotary brush to remove all carbon crust from the cylinder head injector sleeve. Blow out debris with compressed air.
- Copper Washer Sizing: Install exactly one brand-new 1.5mm thick copper washer per injector. Never stack two washers. Stacking washers raises the nozzle tip by 1.5mm, misaligning the fuel spray cone outside the piston combustion bowl and causing thick black smoke and severe loss of engine torque.
- Ceramic Anti-Seize Paste: Apply a microscopic film of high-temperature, metal-free ceramic assembly paste to the injector steel body to prevent electrolytic seizure in the cylinder head. Keep all paste at least 25mm away from the nozzle tip and spray orifices.
- ### 4. Dynamic Backleak Test & Return Flow Acceptance Criteria
- Perform an injector return flow quantity test when troubleshooting P0087 or hot hard-cranking:
- Engine Cranking Speed (Starter Only): Return flow must not exceed 5 ml per cylinder over a 10-second cranking period.
- Engine Warm Idle (650-750 RPM): Return leakage must remain below 35 ml/min per injector.
- Engine Full Load / Relief Pressure (1600 bar): Maximum allowable backleak is 50 ml/min per injector.
- Diagnosis: Any injector exceeding 45 ml/min at idle indicates internal F00RJ02130 control valve seat erosion and must be replaced immediately.
Frequently Asked Questions
Can I use Bosch 0445120231 to replace the older 0445120059 on my Komatsu PC200-8?
Yes, absolutely. The 0445120231 is Bosch's official upgraded and direct drop-in replacement for the discontinued 0445120059 injector. It features identical mounting dimensions, spray angle, and flow rating, while incorporating an improved internal control valve (F00RJ02130) and hardened DSLA128P5510 nozzle for significantly enhanced service life in harsh construction environments.
Does the 0445120231 common rail injector require IMA / QR coding into the engine ECU?
No. The CRIN2 fuel injection system on Komatsu SAA6D107E-1 and Cummins QSB6.7 industrial engines relies on precision mechanical bench calibration and does not utilize individual injector IMA compensation codes. Once physically installed according to the 3-step torque procedure, the engine will start and run smoothly without scan tool programming.
What are the symptoms of a leaking fuel feed connector tube on a Cummins QSB6.7?
A loose or damaged connector tube allows 1600 bar fuel to escape internally under the valve cover directly into the engine lubricating oil. Key warning signs include a rising engine oil level on the dipstick, a distinct diesel fuel odor in the crankcase, and low rail pressure fault code P0087 accompanied by long engine cranking times before starting.
Why does my Komatsu excavator suffer from long cranking times when the engine is hot?
Hot hard-cranking is the classic signature of worn injector control valves (F00RJ02130). When diesel fuel warms up, its viscosity drops significantly, allowing high-pressure fuel to bypass eroded valve seats directly into the fuel return line. The starter motor cannot spin the high-pressure pump fast enough (only 150-200 RPM) to overcome this excessive return leakage and achieve the minimum 250 bar cranking rail pressure.
What is the correct tightening torque for the injector hold-down clamp bolt?
The hold-down clamp bolt is a torque-to-yield (TTY) stretch bolt. The official factory procedure specifies torquing the bolt to 8 N·m (71 in-lbs), followed by a 90-degree clockwise angle turn (yielding approximately 28-32 N·m of equivalent fastener tension). Never reuse stretched or damaged clamp bolts.
Can I replace only one faulty injector, or must I replace all six together?
While replacing all six injectors ensures balanced cylinder performance and prevents subsequent downtime on a high-hour machine, it is technically permissible to replace only the single injector failing the backleak test. However, you must always install a brand-new fuel feed connector tube and copper washer for each disturbed cylinder.
Which OEM part numbers correspond to this 0445120231 injector?
This injector corresponds directly to Komatsu OE part numbers 6754-11-3010, 6754-11-3011, and 6754-11-3012 (6754113010 / 6754113011 / 6754113012), as well as Cummins part numbers 4945969, 5263262, 3976372, and 5263314NX. The official Bosch remanufactured exchange part numbers are 0986435550 and 0986435597.
What is the electrical resistance specification for the 0445120231 solenoid coil?
Using a digital multimeter, check the electrical resistance across the two solenoid terminal studs at 20°C (68°F). The normal coil resistance must measure between 0.25 and 0.50 Ohms. Resistance below 0.20 Ohms indicates an internal short circuit, while resistance above 0.60 Ohms or infinite resistance (OL) indicates a broken internal winding or high-resistance connection.
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.
Technical Diagnostic & Service Protocols
Authoritative field procedures, diagnostic testing thresholds, and service SOPs for this assembly.