This is the Alliant Power AP55177, a common-rail fuel injector remanufactured by Alliant Power. It replaces Cummins injector 5254261, which is the Bosch CRIN3 injector 0445120177, on the 6.7L Cummins inline six: the QSB6.7 industrial engine and ISB6.7 engines built with that same injector. Bosch remanufactures the same injector as 0986435697. The engine takes six, and a refundable core applies.

Hard starting, a miss, haze at idle, low power or fuel in the oil are the usual reasons these come out. Dirt and water in the fuel do most of the damage, so change the filters and find the source before the new injectors go in. The 6.7L Cummins was built with many different injectors, and they are not the same part: Bosch 0445120231 (Cummins 5263262), Bosch 0445120251 (Cummins 5263314) and Bosch 0445124019 (Cummins 5289266) are examples, and Ram pickup and chassis cab injectors carry other numbers again. Order by the number on your old injector or by engine serial number.

Specifications

Fits / Applications

• Cummins QSB6.7 industrial engines that call for Cummins injector 5254261
• Cummins ISB6.7 engines that call for the same Cummins 5254261 injector
• Six injectors per engine
• Not the same injector as Bosch 0445120231 (Cummins 5263262), Bosch 0445120251 (Cummins 5263314) or Bosch 0445124019 (Cummins 5289266)
• Ram pickup and chassis cab 6.7L engines use other Bosch numbers

Use new seals on each injector and inspect the high-pressure connector (feed) tube for that cylinder. Replace any tube with a worn or marked sealing tip. Change the fuel filters and flush out any water or dirt before start-up. Follow the Cummins service information for your engine for any injector setup step with Cummins INSITE or an equivalent service tool.

Part Numbers & Cross Reference

Cummins 5254261  ·  Cummins (suffix versions) 5254261NX, 5254261PX, 5254261RX  ·  Cummins (also listed) 5579332  ·  Bosch new 0445120177  ·  Bosch remanufactured 0986435697  ·  Bosch remanufactured (also listed) 0986435705

Cross-reference numbers can change with engine serial, build year and emissions tier, so treat this list as a starting point. Send us your engine serial number and we will confirm the exact match against your build before anything ships. That check is free and takes a few minutes.

Frequently Asked Questions

Will the AP55177 fit my Cummins QSB6.7?

It fits QSB6.7 engines that call for Cummins injector 5254261, which is Bosch 0445120177. QSB6.7 engines were built with several different injectors, so check the number on your old injector or call 530-668-0818 with the engine serial number and CPL.

What numbers does the AP55177 replace?

Cummins 5254261 and its suffix versions 5254261NX, 5254261PX and 5254261RX, new Bosch 0445120177 and the Bosch remanufactured number 0986435697.

Who remanufactures it, and is there a core?

It is remanufactured by Alliant Power. A refundable core applies, and it is refunded in full when we receive your rebuildable old injector.

Is it the same as Bosch 0445120231 or 0445124019?

No. 0445120231 is Cummins 5263262 and 0445124019 is Cummins 5289266. Both are different parts from the Cummins 5254261 injector this one replaces.

Related Parts

• Cummins QSB6.7 Common-Rail Fuel Injector | Bosch 0445120251 New (Cummins 5263314)
• Cummins QSB6.7 Tier 4 Common-Rail Fuel Injector | Bosch 0445124019 New (Cummins 5289266)
• Cummins QSB4.5, QSB5.9 & QSB6.7 Common-Rail Fuel Injector | Alliant Power AP55597 Remanufactured
• Cummins QSB4.5 & QSB6.7 Tier 4 CP4.2 High-Pressure Fuel Pump | Bosch 0445020609 New

Why Buy From Valley Fuel Injection

We are a diesel fuel-injection and turbocharger shop in Woodland, CA, rebuilding pumps, injectors and turbos on our own benches since 1993, not a drop-ship storefront. When you call, you talk to the people who test these units. We verify fitment against your engine serial, VIN or build date before anything ships, so the right part arrives the first time.

Not sure the injectors are the problem? We test and diagnose in-house before you buy. See our common rail injector testing and rebuild service.