What Is the 4W2448 Oil Pump?
The 4W2448 oil pump (also written 4W-2448) is the engine lubrication pump for Caterpillar 3304 and 3306 diesel engines. It is a gear-type pump that circulates engine oil to the crankshaft bearings, camshaft, pistons and valve train, keeping metal surfaces separated under heavy load. When an oil pump on a 3300-series engine wears out, oil pressure drops first — and if the problem is ignored, the engine can suffer bearing damage that costs far more than the pump itself.
Most replacement 4W2448 pumps on the market today are direct bolt-on units: same mounting flange as the original, built-in pressure relief valve, and a weight of roughly 10–13 kg (22–29 lb). The pump serves both the 3304 and the 3306 engine families, which is why it appears on such a wide range of CAT machines — from 215C and 225 excavators to 930 wheel loaders, D6-track-type tractors and 140G motor graders.
Which Engines and Machines Does the 4W2448 Fit?
Buyers often search this pump by machine model rather than part number, so here is the fitment range in one chart. Note the engine column: most 215/225/229-series excavators are powered by the 3304, while the 235 series and most wheeled machines run the 3306. If you are unsure which engine your machine carries, the serial number check below settles it in seconds.
| Machine category | Typical models | Engine |
|---|---|---|
| Excavators | 215B, 215C, 215D, 219D, 225, 225B, 225D, 229, 229D, 235, 235B, 235C, E240, E300, E300B | 3304 (215/219/225/229 series), 3306 (235 series) |
| Wheel loaders | 930, 930R, 936, 950B, 950E, 966C, 966D, 966F, 966R, G936 | 3304 / 3306 |
| Track-type tractors | D4E, D5B, D5H, D6D, D6E, D6H, D7F, D7G, D7H | 3304 / 3306 |
| Motor graders | 120G, 12G, 130G, 140G, 14G, 160G | 3304 / 3306 |
| Wheel tractor-scrapers | 615, 615C, 621E, 621R, 627B, 627E, 637D, 637E | 3306 |
| Articulated trucks | D250B, D25C, D25D, D300B, D30C, D350C, D35C | 3306 |
| Wheel dozer | 814B | 3306 |
| Pipelayers | 561D, 571G, 572G | 3304 / 3306 |
| Engine applications | Generator sets, industrial power units, marine propulsion, trucks | 3304, 3304B, 3306, 3306B, G3304, G3306 |
This is one of the reasons the 3300 series stays popular with fleet owners decades after production: one pump part number covers dozens of machines, which simplifies stocking for repair shops and parts distributors.
4W2448 Cross Reference Numbers
You may find any of the following numbers stamped on the pump housing or printed on your old part’s box. They all refer to the same pump family. If your number is on this list, you are looking at the right pump:
| Reference number | Where you’ll see it |
|---|---|
| 4W2448 / 4W-2448 | Original Caterpillar part number |
| 6I1346 / 6I-1346 | Common interchange used by aftermarket suppliers |
| 8N-8635 / 8N8635 | Older CAT reference, still quoted by some dealers |
| 2P1785 | Interchange appearing in supplier catalogs |
| 4P4020 | Interchange appearing in supplier catalogs |
| 295-5674 / 2955674 | Alternate reference |
| 1167589 | Alternate reference |
| 341310 (PAI) | PAI Industries aftermarket reference |
One practical tip: the number cast into the housing is sometimes the casting number, not the service part number. When in doubt, match against your engine serial number — see the method below.
Signs Your 4W2448 Oil Pump Is Failing
An oil pump rarely fails without warning. On a healthy 3306, oil pressure at operating temperature typically reads around 0.15 MPa (about 22 psi) at low idle and up to roughly 0.6 MPa (about 87 psi) at high idle — always confirm against the values in your engine’s service manual for your specific configuration. Watch for these symptoms:
- Low oil pressure at operating temperature. The most common signal. Pressure that reads fine cold but drops when the oil heats up points to worn pump gears or excessive bearing clearance.
- Pressure that fluctuates with RPM. A stuck-open relief valve or a suction-side air leak causes unstable readings.
- Knocking or ticking from the bottom end. Bearings that lose their oil film start to rumble — by the time you hear it, the pump has been weak for a while.
- Metal particles in the oil or filter. Gear wear inside the pump sheds particles that end up in the filter element. Cut the filter open during your next service and look.
- Climbing engine temperature under load. Less oil flow means less heat carried away from the pistons and bearings.
Before you order a new pump, rule out the cheap causes first: check the oil level, verify the pressure gauge itself works, inspect the filter and its bypass valve, and make sure the suction tube screen is not clogged. Any of these can mimic a worn pump. If the basics check out and pressure is still low, the pump gears or housing bore are worn — replacement is usually more economical than a rebuild on this pump, since the housing and gears wear together.
How to Verify Fitment with Your Engine Serial Number
Machine model names alone can be ambiguous — several models changed engines mid-production. The engine serial number (ESN) removes all doubt. You will find it stamped on the engine valve cover or on the block data tag. Compare the two-letter prefix against this table:
| ESN prefix | Machine | Engine |
|---|---|---|
| 9YB | 215B excavator | 3304 |
| 4HG | 215C & 219 excavator | 3304 |
| 9TF | 215D excavator | 3304 |
| 5XG | 219D excavator | 3304 |
| 76U | 225 excavator | 3304 |
| 1AG | 225B & 229 excavator | 3304 |
| 6RG | 225D LC excavator | 3304 |
| 2LJ | 229D excavator | 3304 |
| 32K / 81X | 235 excavator | 3306 |
| 1FD / 4ED | 235B excavator | 3306 |
| 2PG / 3WG | 235C excavator | 3306 |
Don’t see your prefix in the table? That does not mean the pump won’t fit — the 3300 family was used in dozens of applications. Send us your full serial number and we will confirm the correct pump before anything ships.
Free fitment check: send your engine serial number, machine model and the nameplate photo of your old pump to our contact page or straight to sales@atospumps.com. We reply with fitment confirmation within 24 hours — no cost, no obligation.
What to Check Before Ordering an Aftermarket 4W2448
Aftermarket is where the value is on a pump like this — but quality varies widely between suppliers. Before you commit an order, put every candidate through this checklist:
- Casting quality. The housing should be dense, uniform cast iron or steel with no visible porosity. Porous castings weep oil and fail early under thermal cycling.
- Gear machining tolerances. Precision-machined gears with tight housing clearances hold pressure at operating temperature; sloppy gears lose pressure as everything heats up and expands.
- 100% bench testing. Ask whether every pump is tested for pressure output and leakage before packing, not just sampled. A supplier who tests every unit will say so without hesitation.
- Relief valve function. The built-in relief valve protects the lubrication circuit from over-pressure. It should be verified during testing, not assumed.
- Warranty terms in writing. One year is a common standard on this pump family. Get the coverage and the claim process in writing before payment, not after a problem.
- Export-grade packing. A 10 kg cast-iron pump in a thin carton does not survive ocean freight. Confirm wooden-case or reinforced export packing, especially for sea shipments.
- Fitment confirmation service. A serious supplier checks your serial number against their cross reference data before shipping — not after you discover the bolt pattern doesn’t match.
Walk through this list on your next inquiry and you will separate the factories from the resellers within one email exchange. The answers tell you who actually controls production and who is just forwarding your order.
Frequently Asked Questions
Is 4W2448 the same as 6I1346?
They are interchangeable references for the same oil pump used on CAT 3304 and 3306 engines. Suppliers list one or the other (or both) depending on their catalog source. If your old pump carries either number, the same replacement covers it — and the serial number check above confirms it for your exact machine.
Does the 4W2448 fit the 3304 or the 3306 engine?
Both. The pump serves the whole 3300 family, which is exactly why it appears across so many machine models. The 215/225/229-series excavators typically carry the 3304; the 235 series and most wheel machines carry the 3306. The pump fits both — verify your engine prefix to be certain before ordering.
How long does shipping take?
Lead time depends on stock and your destination port. Stocked orders for North and South America typically move by air courier in days or by sea in a few weeks; we confirm the exact schedule with your quotation. Send your destination port with the inquiry and you will get a realistic delivery date, not a guess.
Can I order just one pump, or is there a minimum?
Single-unit orders are generally accepted for this part — repair shops rarely need bulk quantities of one pump number. If you are a distributor stocking the 3300 family, ask about mixed-part consolidation so you can fill a container with a range of numbers instead of one.
Get a 4W2448 Oil Pump with Fitment Confirmed Before It Ships
Every week a mismatched pump crosses an ocean because someone ordered from a catalog listing without checking. It takes one email to avoid that. Send us your engine serial number, machine model, quantity and destination port, and you will receive fitment confirmation and a quotation within 24 hours.
- Request a quote: inquiry form · Email sales@atospumps.com
- Browse the full 4W2448 specifications on our 4W2448 oil pump product page
- Need other types of our oil pumps? Start from the oil pump category guide here.
Written by the engineering team at AtosPumps — manufacturing replacement engine pumps for CAT 3300-family equipment and exporting to 30+ countries for over 20 years, including the USA, Mexico, Brazil, Argentina, Chile, Peru, Colombia, Morocco, Algeria, UAE, Saudi Arabia, Oman and South Africa. Every pump is 100% pressure-tested before packing and covered by a written warranty.
