This is the Alliant Power AP53906, a common rail fuel injector remanufactured by Alliant Power for the Isuzu 6HK1 7.8L diesel. Catalogs list it for the 2007 to 2009 Chevrolet Kodiak C6500 and C7500 and the T6500 and T7500 tilt cabs. It is the later injector of the family: AP53904 and AP53905 cover the 2004 to 2007 engines. A refundable core applies.

Rough idle, a miss, hard starting, white or black smoke, fuel in the oil and rail pressure faults are the usual reasons these injectors get pulled. Water or dirt in the fuel does most of the damage, so check the filters and the tank before you fit new ones. The 6HK1 is an inline six and takes six injectors.

Specifications

Fits / Applications

• Chevrolet Kodiak C6500 and C7500 with the Isuzu 6HK1 7.8L, 2007 to 2009
• GM T6500 and T7500 with the Isuzu 6HK1 7.8L, 2007 to 2009
• Six injectors per engine
• 2007 trucks can take the earlier injector. Confirm by engine serial number.

Fit new fuel filters and make sure the tank and lines are clean before the engine runs. Keep every fuel connection capped until it is made up, use new sealing washers and O-rings, and torque the hold-downs and high-pressure lines to the Isuzu service manual figures.

Part Numbers & Cross Reference

Alliant Power AP53906  ·  Earlier 6HK1 injector, 2004 to 2007 AP53904  ·  Earlier 6HK1 injector, 2004 to 2007 AP53905

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 AP53906 fit my 2007 Kodiak with the 7.8L Isuzu?

It may. 2007 is the changeover year, with AP53904 and AP53905 listed for 2004 to 2007 and AP53906 for 2007 to 2009. Call 530-668-0818 with your engine serial number and the numbers on your old injector.

Does the AP53906 replace AP53904 or AP53905?

We cannot confirm that it does. Those two are listed for the 2004 to 2007 6HK1, and AP53906 is listed for 2007 to 2009. They are separate part numbers, so match the one on your old injector.

Is the AP53906 new or remanufactured, and is there a core?

It is remanufactured by Alliant Power. A refundable core applies, and it comes back when we receive your old injector.

How many injectors does the 6HK1 take?

Six. The 6HK1 is a 7.8L inline six, and most shops replace them as a set so the cylinders stay balanced.

Related Parts

• 2003 Isuzu FTR, FVR, Chevy Kodiak & GMC TopKick 6HK1 7.8L Fuel Injector | Alliant Power AP53801 Remanufactured
• 2008-2010 Isuzu NPR, NPR-HD, NQR & NRR 4HK1 5.2L Fuel Injector | Alliant Power AP53907 Remanufactured
• 2005-2007 Isuzu NPR-HD, NQR, NRR & GMC W4500 4HK1 5.2L Fuel Injector | Alliant Power AP53903 Remanufactured
• Isuzu 4LE2 2.2L Tier 4 RHF3 Turbocharger | IHI F31CAD-S0182B New (Isuzu 8982236170)
• Common Rail Diesel Injector Testing & Rebuild Service

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.