The Alliant Power AP55101 is a remanufactured XPI common-rail fuel injector for the Cummins ISX15 (14.9L) built to EPA10 emissions. It replaces Cummins 5579417 and 2872405. Catalogs also list it for QSX15 engines that use the same Cummins injector. It comes with a new high-pressure connector tube, the nozzle gasket installed and a new injector body seal.

XPI injectors wear from high hours and dirty fuel. Typical signs are hard starts, rough idle, a miss, smoke, low power and injector fault codes. Each injector carries its own trim code, and the new code must be entered with a scan tool after install. Cummins used more than one XPI injector on its 15L engines, so check your CPL before you order.

Specifications

Fits / Applications

• Cummins ISX15 (14.9L) XPI engines built to EPA10 (confirm by CPL)
• Cummins QSX15 engines that use Cummins injector 2872405 / 5579417 (confirm by CPL)
• Class 8 trucks with an EPA10 ISX15, including Freightliner, Kenworth and Peterbilt models

Clean the injector bore before the new injector goes in, and keep the open fuel system capped. Lube the injector O-ring with clean engine oil. Always fit a new high-pressure connector (feed) tube with the injector; one comes in the box. Start the hold-down bolt, seat the connector tube, then torque the hold-down bolt and the connector tube nut in stages (pre-torque both, then final torque) to Cummins specs. Route the injector harness clear of the rocker levers and engine brake. Enter each injector’s trim code with a scan tool; the label on the injector shows the part number, serial number and trim code. Change the fuel filters at the same time.

Part Numbers & Cross Reference

Cummins 5579417  ·  Cummins 5579417PX  ·  Cummins 5579417RX  ·  Cummins 2872405  ·  Cummins 2872405PX  ·  Cummins 2872405RX  ·  Cummins 2872405NX

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

Which engines does the Alliant Power AP55101 fit?

The Cummins ISX15 (14.9L) XPI engine built to EPA10 emissions. Catalogs also list it for QSX15 engines that use Cummins injector 2872405 / 5579417. Confirm by CPL.

What Cummins numbers does AP55101 cross to?

Cummins 5579417 and 2872405, along with 5579417PX, 5579417RX, 2872405PX, 2872405RX and 2872405NX.

How do I tell AP55101 from the other 15L XPI injectors?

Several look alike. AP55102 (5579415 / 2894920) is another ISX15 / QSX15 XPI injector, AP55100 (5579419) is ISX15 EPA13 and AP55128 (5579421) is X15 EPA17 and later. Call 530-668-0818 with your ESN and CPL, or the Cummins number on your old injector, and we confirm it at no charge.

Is the AP55101 remanufactured, and what is in the box?

It is a remanufactured Alliant Power injector. It comes with a new high-pressure connector tube, the nozzle gasket installed and a new injector body seal. The core charge added at checkout is refundable, and we refund it when we receive your rebuildable core.

Related Parts

• Cummins X15 & ISX15 EPA17 to EPA24 XPI Common-Rail Fuel Injector | Alliant Power AP55128 Remanufactured
• Cummins ISX15 Reman Turbocharger HE451VE with Actuator | Alliant Power AP90924 (EPA10)
• Cummins ISX12 XPI Fuel Injector | Alliant Power AP55103 Remanufactured
• Cummins ISX15 Reman Turbocharger with Actuator | Alliant Power AP90951

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. Confirm fitment against your engine serial, VIN or build date before you order. Call us and we will help you match the right part.