F00RJ01727 Control Valve Replacement for Bosch 0445120086 0445120391

The 0445120086 injector is the unit normally carried on a WP12 application in this family, and the sibling injector 0445120391 covers the WD615 / WD618 series trucks. The same matched valve is fitted across the Weichai CRI2-16 line (0445120087, 0445120127, 0445120166, 0445120265, 0445120266, 0445120388, 0445120088), so a fleet running several models can standardise on one control valve number and one stock line.

Fitment check. Confirm three things before you order: the injector number stamped on the injector body, the engine code shown on the vehicle’s engine code plate, and the vehicle itself (chassis number or VIN). If any of the three disagrees with the table above, send us a photo of the valve and the injector and we will confirm the match first.

A control valve must match the injector it is built into, because the cap calibration is set for that injector. This valve is listed for the Bosch CRI2-16 injectors 0445120086 and 0445120391. If your vehicle runs a Cummins or another common rail injection system, this valve is not the right part — check the injector number first.

In a modern common rail injection system, a diesel common rail injector is opened by a fuel injector control valve rather than by a mechanical linkage — and a fuel injector valve of this type decides both timing and quantity. The F00RJ01727 is that valve for the Bosch CRI2-16 injector. It sits at the top of the injector, above the nozzle, and it decides when the high-pressure fuel that has built up inside the injector is released back to the return line. When the solenoid is energised, the valve lifts and the pressure above the needle drops; the needle then opens and the nozzle sprays. When the solenoid is released, the valve closes again and the injector is ready for the next injection event.

Because the valve is on the return side, it is a precision metering part and not just an on/off tap. The small hole machined into the valve cap, the matching face on the valve stem, and the ball that seals the return orifice together set how much fuel is returned on each cycle. That is why the cap carries an engraved calibration face: the valve is matched to its injector so the return quantity stays inside tolerance. Two valves can look identical and still be calibrated differently, which is the single most common reason a rebuilt injector runs badly after a valve swap.

In service the valve wears in a few predictable ways. Diesel is not perfectly clean, and fine debris laps the stem and the cap bore over time. Heat and pressure cycling can leave the sealing face of the ball and seat slightly grooved or varnished. A valve that no longer seals cleanly returns too much fuel, so rail pressure takes longer to build and the injector delivers less fuel than the ECU expects. The engine compensates as far as it can through the fuel correction map, but once the correction runs out the cylinder starts to misfire, knock or smoke.

The F00RJ01727 is supplied here as a control valve assembly — the cap, stem and ball seat as one matched unit — for the Weichai engine family through its parent injectors. It is a Vidishi Auto compatible replacement, built to the Bosch CRI2-16 specification and sold under our own brand; it is not a genuine Bosch-branded part and we do not describe it as one. For buyers rebuilding Bosch CRI2-16 injectors, matching the valve to the correct injector number is what keeps the repair on specification.

Older injector valves were set by shim thickness; the CRI2-16 family sets return flow through the cap calibration instead. That is why this part belongs with the common rail injector parts that cannot be ordered by eye. Alongside the other Bosch common rail injector parts used on the same injectors, it is stocked by rebuilders as injector spare parts together with the wider diesel fuel injector parts a Weichai rebuild consumes.

How we label data. Confirmed values are backed by more than one independent catalogue; Reference values come from the Bosch cross-reference for the parent injector and say which unit this valve belongs to rather than claiming OE origin; Not published means we leave the field blank rather than guess it. Rows marked Not published are left blank on purpose. A control valve’s return and sealing behaviour is verified on the injector test bench, so we do not publish a figure we cannot stand behind.

Buyers usually reach this page from an injector cross reference rather than a valve code, so it helps to read the list as a map. This F00RJ01727 cross reference covers the parent and the sibling injector; it is not a substitute list. The 0445120086 control valve and the 0445120391 control valve are the same assembly from this page’s point of view, and the Bosch F 00R J01 727 formatting is simply how the number is written in Bosch catalogues. Where another catalogue lists a direct F00RJ01727 equivalent, match it against the injector number before you order.

Cross-reference numbers are shown as Reference — they tell you which injector and system the valve belongs to. They are not a claim that this part is interchangeable with every number in the list without checking the injector.

• Rough idle and injector misfireWhen the valve returns too much fuel, the affected cylinder gets less fuel than the ECU expects. An intermittent injector misfire at idle is usually the first report.
• Hard starting, long crankRail pressure takes longer to build if the valve does not seal, so the engine cranks before it fires.
• Fuel knock or sharp rattleOver-returning valves change injection timing and quantity, which shows up as combustion knock under load.
• Black smoke and poor powerA black smoke diesel engine complaint usually follows under-fuelling on one cylinder — the engine smokes and loses pulling power on hills.
• High return flow on the benchA valve that no longer seats cleanly shows up immediately as excessive back-leakage during a return-quantity test.
• Injector leakage past the seatFuel tracking back through the return path raises return flow and, on a badly worn valve, can pass fuel past the injector body.
• Fuel in the oil / strong smellA badly worn return path can thin the engine oil over time, which is what turns a small valve fault into a much larger repair.

Because these symptoms overlap with nozzle wear and injector coding problems, confirm the fault on the test bench and by return-quantity before replacing the valve. Read them as early warning of injector failure rather than proof: a valve code match plus a bench number is the reliable path, guessing from the symptom alone is not.

1. 1. Remove and cleanPull the injector with the correct injector removal tool, then clean the body and bore before any valve work. Dust entering the valve is the fastest way to ruin a new one.
2. 2. Strip on a clean benchWork on a lint-free surface. Keep the cap, stem and ball seat together and note the cap engraving before you disturb anything.
3. 3. Inspect the bore and seatCheck the cap bore and the ball seat for grooves, varnish or damage under magnification. A scored seat needs more than a new valve.
4. 4. Fit the matched assemblyInstall the control valve assembly as a matched unit. Keep the side inlet port aligned as the injector body requires.
5. 5. Reassemble and codeReassemble the injector, fit new seals, and set the injector coding the ECU expects for the rebuilt unit. Injector installation torque and sequence follow the figures used for the parent injector.
6. 6. Verify on the benchRun a return-quantity and leak test on an injector tester before the injector goes back on the engine. Bench numbers, not road feel, tell you it is right.

A control valve installation is a bench job: keep the bench clean, keep the assembly matched, and let the numbers decide. If you would rather not rebuild in-house, ask us for the parent injector 0445120086 as a complete unit instead, or read the installation guide and maintenance guide for the wider service routine.

Every F00RJ01727 control valve is covered by a 6-month warranty against manufacturing defects. This control valve warranty covers a valve that is out of tolerance when it arrives or fails early because of how it was made, not damage caused by dirt, incorrect fitting or a separate fault in the injector it is paired with. Like every injector spare parts warranty we issue, it is a supplier warranty from us and not a Bosch control valve warranty.

Warranty is a component-level cover: it applies to the control valve as supplied. It does not extend to the whole injector or to engine damage, and it is separate from any warranty on the injector you rebuild.

The F00RJ01727 is a common line item for anyone rebuilding Bosch CRI2-16 injectors for Weichai engines. We supply it to workshops, injector rebuilders and fleet operators who need a dependable valve rather than a one-off. Minimum order is 1 pc, and larger rebuild quantities are quoted per order.

We act as a control valve supplier and as a wider common rail injector parts supplier for export, and we build this line ourselves as the injector valve manufacturer behind the Vidishi Auto brand. Injector control valve wholesale pricing is quoted per order from the 1 pc minimum, and rebuilders who take diesel injector parts bulk-packed can put several CRI2-16 service lines on the same order.

The packaged dimensions above are the shipping figures for a single valve; the bare valve measurements are listed as Reference so you can check them against a parts diagram. Lead time is quoted per order and depends on quantity. Control valve export shipping is quoted per shipment and every injector parts export order leaves with its paperwork in place. Read our shipping information for freight options, and track your order once it ships.

A control valve is a small part with an outsized effect on how an injector runs, so control valve quality is checked unit by unit rather than by sample. Every batch passes an injector control valve check for stem freedom, sealing-face condition and clean orifices. Rather than publish reviews we cannot verify, we tell you how the part is inspected and let your test bench be the judge.

Control valve technical support starts with the injector number, and it is free before you order: send us the injector number, the vehicle and the valve code and we will check it against the F00RJ01727 listing before quoting. Ordering the wrong valve is the most common way a rebuild goes wrong, so we would rather spend a message confirming the part than have you bench a valve that does not match. Diesel injector support continues after delivery — bench figures, fitment questions and warranty claims all go to the same team.

Supplier note. WholesaleAutoPartsDirect is an independent supplier of compatible automotive parts and is not affiliated with, endorsed by or acting as an agent of Bosch or Weichai. Brand names and part numbers are used for reference and fitment only.