What The 4955830 Cooler Does
The oil cooler core sits between the oil filter head and the block on the ISX15 family, stacked aluminum plates with engine oil on one side and coolant on the other. Oil comes off the pump hot, dumps heat into the coolant loop, and goes back out to the mains, rods and piston cooling nozzles at a temperature the film can survive.
This is a core, not a complete housing assembly. You reuse the housing and replace the plate stack along with the gaskets and seals. The unit listed here is aluminum, plate-style, built for Class-8 over-the-road duty cycles where the engine spends hours at load and the cooler never gets a break.
It is sold as an aftermarket direct replacement with no core return required. That matters when the truck is down and you don't want to track a dirty core back through the counter to get credit released.
Why These Numbers Cross
4955830 is the headline number. Cummins numbers 4965482 and 4955831 show up on the same physical cooler core through supersessions and packaging changes over the ISX15 and X15 production run. A number gets retired, a new one is issued, and the part on the shelf keeps the same plate count, port locations and sealing surfaces.
PAI 141446 is an aftermarket number covering the same core. PAI catalogs by application, so their number lands on the same footprint even though the digits look nothing alike. We list it for identification only — it is how a lot of shops have the part written down in their own inventory system.
Cross-reference gets you to the right family. It does not confirm fit on your specific unit. Read the number stamped or tagged on the cooler you pulled, and check the engine serial number, before you commit.
How These Coolers Fail
Internal cracking between plates is the common one. Oil pressure is higher than coolant pressure, so the first symptom is usually oil pushing into the coolant — brown film in the surge tank, a slick on the coolant when it cools. Run it long enough with the engine off and pressure equalizes, and coolant migrates into the oil pan instead.
Check the obvious alternatives before you condemn the cooler. Head gaskets, liner o-rings and a failed compressor can all put coolant where it doesn't belong. Pressure test the cooler off the engine before you order, and inspect the housing sealing face for pitting and erosion while it's apart.
Replace all gaskets and o-rings on reassembly, torque the housing bolts in sequence, and flush the cooling system if oil got into it. Contaminated coolant swells seals downstream and you'll be back in the same spot.
4955830 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 4955830. 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 | 4965482, 4955831 |
| PAI | 141446 |
Frequently asked questions
Is 4965482 the same cooler as 4955830?
They cross to the same plate-style oil cooler core for the ISX15 family. Cummins numbers move through supersessions over a long production run, and the physical part carries forward. Confirm against the number on your old cooler and your engine serial number before ordering, since cross-reference is a starting point, not a fitment guarantee.
Does this come with gaskets and seals?
This listing is the cooler core itself. Plan on sourcing the housing gaskets and o-rings separately and replacing every one of them — reusing a compressed gasket on an oil-to-coolant joint is how you end up doing the job twice. Inspect the housing sealing surface at the same time.
How do I know it's the cooler and not the head gasket?
Pull the cooler and pressure test it off the engine with the ports capped. A cracked core will show a leak-down or bubbles. If the cooler holds, look at head gaskets, liner o-rings and the air compressor before you spend money. Oil in the coolant on an ISX15 has more than one cause.
Not sure it fits? We check before you pay.
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.
More cross-reference guides
Need the part, not just the reading?
Every part below is a Premium Quality aftermarket Direct Replacement with published OEM cross-reference numbers, a 6+ month warranty and same-business-day shipping from Tacoma, WA. Not sure it fits? Run your VIN — or call and a person who knows trucks will verify fitment before you pay.