This is a genuine Cummins part for the High-Pressure Fuel Pump (HPFP) used on Cummins ISX15 engines from the 2011-2016 model years, specifically aligned with the EPA 2010 and GHG14 emissions standards.

Here is a detailed breakdown of what this part is and key information you should know:

Part Details:

• Part Number: 4359487

• Description: High-Pressure Fuel Pump (often called the fuel injection pump or gear pump).

• Application: Cummins ISX15 CM2250 & CM2350 engines (2011-2016).

• Emissions Compliant: EPA 2010 / GHG14. This is a critical detail when replacing this pump.

Important Compatibility & Application Notes:

1. Must Match Emissions Series: This pump is designed for engines with the XPI fuel system. It is not interchangeable with pumps from earlier (EPA 2007/EPA 2002) or later (GHG17) ISX15 engines without a full and proper conversion kit. Installing the wrong pump can cause severe engine damage and emissions compliance issues.

2. Common Failure & Symptoms: This pump is a known wear item. Failure symptoms often include:

• Loss of Power / Derate

• Difficulty Starting

• Low Fuel Pressure codes (e.g., fault codes related to fuel pressure/rail pressure).

• Increased Oil Level (a classic sign of HPFP failure: fuel diluting the engine oil due to internal leakage).

3. Critical Installation Requirements:

• Fuel Contamination is the #1 Cause of Failure: ABSOLUTELY MUST clean/flush the entire fuel system (tanks, lines, filter base, ECM fuel lines) and replace ALL fuel filters (primary and secondary) when installing a new HPFP. Failure to do so will cause the new pump to fail prematurely.

• Prime the System: The pump and fuel lines must be properly primed to prevent dry-start damage.

• Oil Change Mandatory: If the pump failed internally, you must change the engine oil and filter before running the engine, as fuel contamination of the oil is very likely.

Common Associated Parts (to consider replacing during repair):

• Fuel Filters: Primary (Cummins 3971505 or equivalent) and Secondary (Cummins 5298992 or equivalent).

• HPFP Gasket/Seal Kit: Often Cummins part 4933924.

• HPFP Gear: Often Cummins part 4959630.

• Fuel Line O-Rings and Seals for the connections.
  
  The Cummins ISX15 XPI High-Pressure Fuel Pump (HPFP) represented a significant engineering leap for its time (2010 emissions introduction). Its structural advantages are what allowed it to meet the extreme demands of the XPI (Extreme Pressure Injection) common rail system, which operates at up to 35,000 psi (2,400 bar).

• Here are the key structural advantages of the 4359487 pump:

  1. Dual-Function, Integrated Gear Pump Section

• Structure: The pump incorporates a low-pressure gerotor-style gear pump on its inlet side, driven by the same shaft.

• Advantage:

• Eliminates a Separate Transfer Pump: This simplifies the fuel system architecture, reducing potential leak points and parts.

• Positive Priming & Supply: It ensures a steady, high-volume supply of filtered fuel to the high-pressure section, preventing cavitation—a critical requirement for the next stage.

  2. Radial Piston Design (Multiple Pistons)

  Structure: Unlike the single or dual piston plunger pumps of previous systems, this HPFP uses multiple radial pistons (typically three or four) arranged like a star around the central cam.

  Advantages:

• Smoother Flow & Pressure: Multiple pistons create overlapping pressure pulses, leading to significantly more consistent high-pressure fuel delivery to the common rail, with less ripple. This is crucial for precise injector control.

• Higher Volumetric Efficiency: It can move more fuel per revolution, enabling it to supply enough volume at the extreme pressures needed for clean combustion under all load conditions.

• Reduced Vibration & Stress: The multi-piston design inherently balances forces better than single-piston designs, reducing vibration and component stress.

  3. Hardened Steel Construction & Diamond-Like Carbon (DLC) Coatings

  Structure: Critical components like the pistons, cam ring, and bore are made from ultra-hard, precision-ground steels. The pistons and rollers are often coated with a Diamond-Like Carbon (DLC) coating.

  Advantages:

• Extreme Pressure Resistance: Withstands the incredible internal forces of 35,000 psi operation.

• Exceptional Wear Resistance: The DLC coating is one of the hardest, slickest surfaces available. It drastically reduces friction and wear between the piston foot and its roller, and the piston and its bore—the two highest-wear interfaces in the pump.

• Longevity Under Contamination: While fuel contamination is still the enemy, these hardened materials are more resilient to minor particulate abrasion than older designs.

  4. Integral Pressure Relief & Regulation Valves

  Structure: Advanced solenoid-controlled metering and pressure relief valves are built directly into the pump housing.

  Advantage:

• ECM-Controlled Precision: The Engine Control Module (ECM) can precisely modulate the pump's output in real-time. By controlling the metering valve, it regulates how much fuel enters the high-pressure chamber, allowing for on-demand pressure generation. This improves efficiency and reduces parasitic load compared to pumps that constantly generate maximum pressure.

  5. Compact, Rigid Housing Design

  Structure: The entire assembly is housed in a single, robust aluminum or cast-iron casing that mounts directly to the engine gear housing.

  Advantages:

• Direct Gear Drive: It is driven by the engine's gear train, ensuring positive timing and eliminating the slippage or wear issues possible with belt or chain drives.

• Structural Integrity: The rigid housing maintains perfect alignment of the cam, pistons, and bores under severe thermal and mechanical loads.

• Effective Lubrication & Cooling: Engine oil is circulated through dedicated passages in the pump housing to lubricate the cam, rollers, and bearings, and to help cool the unit.

Here is a summary of the main technical parameters for the Cummins HPFP (Part #4359487)