4PCS Fuel Injector 400903-00074D 7275454 28337917 for Doosan D24 D18 Bobcat Compact Track Loader T450 T550 T590 T595 T630 T650

4PCS Fuel Injector 400903-00074D 7275454 28337917 for Doosan D24 D18 Bobcat Compact Track Loader T450 T550 T590 T595 T630 T650

This fuel injector is a direct replacement unit designed for Doosan D24 D18 Bobcat Compact Track Loader T450 T550 T590 T595 T630 T650. It delivers a precise atomized fuel spray into the combustion chamber for efficient burning. When an injector fails, the affected cylinder runs lean — or doesn’t fire at all — which puts extra stress on the remaining injectors and can damage the catalytic converter over time.

Vehicle Compatibility

Replaces OEM Part Numbers

400903-00074D • 40090300074D • 400903-00074C • 40090300074C • 7275454 • 28337917 • 7516848 • Doosan • Engine • D24NAP • Application • Bobcat

Signs You Need a Replacement

If your equipment is showing any of these symptoms, the injectors & nozzle may be the cause:

• Black or gray exhaust smoke — especially noticeable under load or acceleration
• Rough or uneven idle — the engine shakes or vibrates at low RPM
• Engine misfire or hesitation — stumbling when you step on the throttle
• Poor fuel economy — filling up more often for the same work
• Knocking or nailing sound — metallic noise from the engine under load
• Fuel smell in engine oil — diesel leaking past the injector seat into the crankcase

Replace as a Set

Replacing injectors as a set is the standard practice. Mixing old and new injectors creates uneven spray patterns — the new unit works harder and burns out faster. On multi-cylinder engines, a single failing injector can reduce total output by 20 to 30 percent. When you pull the old injectors, inspect the seats and copper sealing washers. If the seats are pitted or the washers are crushed, replace them before installing the new units.

Frequently Asked Questions

Is this the same as OEM part number 400903-00074D?
Yes. This part directly replaces 400903-00074D and other listed OEM numbers. It matches the original dimensions, connector type, and performance specifications. No modifications are needed for installation.

Do I need any special tools for installation?
Basic hand tools are usually sufficient — wrenches or sockets for mounting bolts, plus a torque wrench if the service manual specifies it. For some applications, you may need a seal puller or a specialized socket. Check your service manual for the specific procedure.

How do I verify this fits my vehicle?
Check the OEM part number on your existing component and match it against the numbers listed above. You can also verify by your vehicle’s engine code (stamped on the engine block) or VIN number. If you’re unsure, send us your vehicle details and we’ll confirm the fit.

Should I replace all injectors or just the bad one?
Replace all of them at the same time if possible. Mixing old and new injectors creates uneven fuel delivery, which makes the new one work harder and shortens its life. It also causes rough running and can clog the DPF or catalytic converter.

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