What This Pump Does
This is the engine lubricating oil pump assembly for the Cummins 15L platform. It is a gear pump with an aluminum housing, driven off the front gear train, pulling oil from the pan and pushing it through the cooler and filter head to the main and rod bearings, cam bushings, turbo and injector train. Everything downstream depends on it holding volume at idle and at rated speed.
Failure is rarely dramatic. Gear-to-housing clearance opens up, the pump loses volume at hot idle, and oil pressure drops off while cold pressure still looks acceptable. Drivers report a low oil pressure warning at stoplights that clears once the truck is moving. On the ISX that same symptom can also come from a worn pressure regulator or plugged cooler, so verify before you condemn the pump.
The other common path to this part number is contamination. A spun bearing or a failed cam follower sends debris through the suction side and scores the gears and the aluminum bore. If you are in the front cover for any reason after a metal-in-oil event, the pump gets replaced, not inspected.
Why These Numbers Cross
2881757 is a Cummins-cataloged lube oil pump number for the 15L ISX family. The Cummins numbers 4309500, 4024814, 4026691, 4955954 and 3800753 are supersession and application-variant numbers for the same pump assembly on that platform. Cummins re-issued numbers as the ISX moved through ISX15 and X15 revisions, so a truck built in one year and one rebuilt later can carry different tags on a functionally identical pump.
PAI 141313 is an aftermarket manufacturer's number for the same assembly. It appears in interchange lists because the aftermarket cataloged the pump under its own numbering while referencing the Cummins numbers for identification. Same mounting pattern, same drive, same port arrangement.
Those numbers are listed here for identification only. PartStop is not affiliated with, endorsed by, or authorized by Cummins, PAI or any other manufacturer. Cross-reference tells you where to start looking, not that the part will bolt to your engine.
Before You Order
Get the engine serial number off the dataplate or the block pad and check it against the number stamped or tagged on the old pump. The ISX ran a long production life across pre-2010 ISX, ISX15, X15 and the QSX15 industrial variant, and the front gear train saw changes. Confirming by serial number or by the number on the part you pulled is the only way to know. Cross-reference alone does not promise fitment.
Plan on new gaskets and the correct shim kit at install. Backlash and gear-to-cover clearance have to be set to spec, not eyeballed. Prime the suction side, run the engine, and check oil pressure hot at idle and at rated speed before the truck goes back out. Also inspect the suction tube and screen while you are in there.
2881757 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 2881757. Use them to identify the part — then confirm the exact fit by VIN or the number stamped on your old unit before you order. An interchange is a starting point, not a fitment guarantee.
| Brand / Line | Cross-Reference Numbers |
|---|---|
| Cummins | 4309500, 4024814, 4026691, 4955954, 3800753 |
| PAI | 141313 |
Frequently asked questions
Will 2881757 fit my 2013 X15 if the old pump is tagged 4024814?
Those numbers cross to the same pump assembly on the 15L platform, so it is a valid starting point. Confirm it against your engine serial number and against the tag on the pump you remove. If your engine has been rebuilt, the installed pump may not match what the original build sheet called for.
How do I know it's the oil pump and not the regulator?
Check pressure with a mechanical gauge at the filter head, hot, at idle and at rated speed. A pump that is worn out loses volume, so hot idle pressure drops while high-idle pressure may still read close to spec. A stuck or worn pressure regulator, a plugged cooler, or a leaking suction tube can produce the same reading, so rule those out first.
Do I need anything else when replacing this pump?
New gaskets and the shim kit for setting gear clearance. You are already in the front cover, so inspect the suction tube, screen and the front gear train for debris. If the pump failed from contamination, find the source before you close it up or the new pump goes the same way.
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Run your VIN and we’ll match parts to your exact truck, or call the counter — a person who knows trucks verifies fitment by OEM number before the order ships. No wrong-box returns.
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