Bosch 0445120400 Common Rail Diesel Injector For CAT C4.4 & Perkins 1204E

This Bosch 0445120400 common rail injector is a solenoid-actuated fuel delivery unit engineered for the Caterpillar C4.4 and Perkins 1204E engine families, delivering precise pilot and main injection events at pressures up to 1,600 bar. Supplied as a direct-fit replacement for workshops and parts distributors handling C4.4 industrial, construction, and generator applications, each unit is bench-tested for delivery stability and back-leakage before dispatch.

The 0445120400 belongs to the Bosch CRI2-16 injector family, using a two-way solenoid control valve (part number F00ZC01310) to meter fuel into the nozzle assembly. The nozzle fitted is the DLLA140P2483 (0433172483), a 4-hole configuration with a 140° spray angle, matched to the combustion chamber geometry of the C4.4 and C7.1 platforms . Each injector carries an individual IMA/ISA correction code that must be programmed into the ECM after installation; failure to enter this code will result in rough running, excessive balance rate deviation, and potential DPF regeneration faults on Tier 4 Final equipment.

This injector is not confined to a single chassis. Beyond the Caterpillar C4.4 and C7.1 engine blocks, it serves the CAT 320D2 and 323D excavator lines, M315D2 and M317D2 wheeled excavators, and the AP500F/AP555F asphalt paver range . Road construction fleets running CB7 through CB16 tandem rollers and CP44B/CS54B compactors will also encounter this part number in their Perkins 1104D-E44TG1 powered units. For generator set operators, the XQP100 and DE88E3 diesel gensets using the C4.4 engine represent a steady replacement demand, particularly in rental fleets where units accumulate high idle hours and the injector's pilot injection quantity drifts out of specification.

The most common comeback on a 0445120400 replacement is not a defective injector-it is contaminated installation. Before fitting, the cylinder head injector bore must be reamed with the correct brush and the copper sealing washer renewed without exception; reusing a crushed washer alters nozzle protrusion and changes the spray cone penetration into the piston bowl . Torque the pressure clamp bolts in two stages following the engine-specific sequence, and never lubricate the injector body where it contacts the bore-only the O-rings and sealing surfaces receive assembly lubricant. After mechanical installation, connect the diagnostic tool and input the correction code from the injector label before cranking. Skipping this step leaves the ECM operating on default injection timing maps, which masks the true performance of the new unit and often triggers a false rail pressure deviation code.

For a diesel repair shop, the 0445120400 represents a high-frequency service item on C4.4 engines that have passed the 4,000-hour mark. The typical failure signature is excessive back-leakage from the control valve seat, producing hard cold starts and a distinct injector knock under light load. Rather than condemning the entire rail system, bench-testing the injector for return flow at 400 bar and 1,000 bar isolates whether the control valve or the nozzle needle is at fault. Because this injector shares its nozzle and valve components with the 0445120399 and 0445120518 references, stocking the complete unit reduces diagnostic downtime and allows the shop to offer a same-day repair rather than a three-day order-in .

Every 0445120400 injector we supply ships with an individual bench test report recording delivery volume across the operating pressure band, back-leakage values, and solenoid response time. We encourage buyers to request the factory floor images showing our assembly and testing stations before placing a stocking order-not as a marketing gesture, but as a verifiable reference point for the production standards behind the part number.

We don't just sell parts; we validate them. Every component we supply undergoes rigorous testing on our in-house calibration benches. We provide full test documentation for our products, ensuring you receive verifiable data rather than generic claims.

Parts Bench Test

Component Performance

Injection Part Test Data

 

Factory Warehousing & Packing Real Shots

 

In addition, original real-shot photos of packing operations from our own workshop are available. All images are captured on-site at our factory workstation rather than stock pictures, allowing you to clearly view the full packaging workflow of our fuel parts, from factory sealing to carton packing.

Cargo Loading Preparation

Finished Goods Warehouse

Manual Warehouse Handling

Q1: Can I install a 0445120399 in place of a 0445120400 if my supplier is out of stock?
A: They share the same nozzle and valve group, but the IMA code and flow classification differ. The ECM will accept the 0399 calibration if you enter its own code, but verify the engine serial break-early C4.4 builds have different injection timing maps that may not tolerate the substitution cleanly.

Q2: What is the most reliable bench test to catch a failing 0445120400 before it triggers a fault code?
A: Run a back-leakage test at 400 bar and compare to the Bosch specification. A return flow exceeding 25 ml/min at that pressure indicates the control valve seat is worn, even if the injector still passes a delivery volume test.

Q3: My customer's 320D2 has a persistent cylinder 3 balance rate correction. Is the injector always the cause?
A: Not always. Check the pressure damping of the rail and the condition of the high-pressure pump inlet metering unit first. A failing pump sends debris downstream that scores the control valve on the new injector within hours.

Q4: Do you supply the copper washer and O-ring kit with the injector?
A: The injector is supplied bare as standard. We strongly recommend ordering the seal kit separately-reusing a copper washer on a C4.4 head is the leading cause of compression leakage past the injector body.

Q5: What is the realistic service life of this injector in a genset application running 24/7?
A: Expect 6,000 to 8,000 hours before back-leakage exceeds specification, provided fuel filtration is maintained to 4-micron absolute and water separation is functioning. Rental fleets with poor fuel handling see failures as early as 3,500 hours.

Q6: Can you provide the test report for a specific serial number before I commit to a 20-unit stock order?
A: Yes. Provide the serial numbers from the carton labels and we will return the bench data sheets for those exact units prior to invoicing.