Description

L5P Duramax Fuel System Contamination Kit (2020–2023)

If your 6.6L Duramax L5P has experienced fuel system contamination, this complete Alliant Power AP57026 kit provides everything needed to properly restore the entire high-pressure fuel system, including the DCR injection pump and all 8 injectors.

Contamination from DEF misfueling, water intrusion, or poor fuel quality can quickly destroy injectors, pumps, and fuel rails. This kit is designed to eliminate guesswork and ensure a complete, reliable repair—not a partial fix that leads to repeat failure.

Why You Need a Complete Fuel System Replacement

When contamination occurs, debris spreads throughout the system. Replacing only one component often results in:

• Repeat injector failure
• Pump damage
• Contaminated fuel rails and lines

This kit addresses the entire system at once, helping prevent costly comebacks and downtime.

Key Features & Benefits

• Complete fuel system solution – Includes injectors, DCR pump, rails, lines, and supporting components
• 100% end-of-line tested injectors and pump for proven reliability
• Plug-and-play DCR fuel pump replacement
• OE-equivalent components for proper fit and performance
• Assembled in the USA in an ISO 9001:2015 certified facility
• 2-year unlimited mileage warranty from Alliant Power
• Pending CARB certification

What’s Included

This kit includes all major components required to restore your L5P fuel system:

• (8) New Common Rail Injectors
• (1) DCR High-Pressure Fuel Injection Pump
• Fuel Rails & High-Pressure Lines
• Return Lines (LH & RH)
• Fuel Cooler
• Aftertreatment Injector
• Diesel Fuel Filter
• Full gasket and seal kit (EGR, intake, coolant, turbo, etc.)
• Mounting hardware and pump nut

(All components are OE-equivalent replacements for proper installation and performance.)

Vehicle Fitment

Fits 2020–2023 6.6L Duramax L5P pickup trucks only:

• Chevrolet Silverado 2500HD / 3500HD
• GMC Sierra 2500HD / 3500HD

Does not fit cab and chassis models.

Common Signs of Fuel System Contamination

• Hard start or no start
• Rough idle or misfires
• Low fuel rail pressure codes
• Injector failure
• Metal debris in fuel system

If you are seeing these symptoms, a complete system replacement is strongly recommended.

Installation Notes

• Professional installation recommended
• Fuel system must be fully flushed before installation
• Always replace filters and clean tank to prevent recontamination