Caterpillar 1R-0751 Fuel Filter

Fitment and Service Notes

The 1R-0751 sits in the fuel system of a machine that spends its life on dirty fuel. On a 320D the element is the second stage of a two-part filter set: fuel passes the 326-1644 fuel/water separator first, where water is coalesced and the bulk of sediment is caught, and then the 1R-0751 removes the fine particles down to 2 microns before the fuel reaches the injection pump. Buyers who replace one element and leave the other in service are the ones who come back a month later with the same power-loss complaint — the worn part is usually the one that stayed in the machine.

The number trap on this element is its near neighbour. The 1R-0750 is the same family of 2-micron advanced-efficiency media and almost the same physical size, but it carries a 1"-14 thread and belongs to the C10–C18 engine class (the 330D/336D machines among them). The 1R-0751 is the 7/8"-14 element. If a listing quotes the 1R-0750 for a 320D, or quotes this element for a 336D, the fitment is wrong even though the part looks right on a screen — see our 1R-0750 page for exactly which machines that element covers.

The rest of the 320D service set is on the site: the Cat 320D filter guide carries the full list (oil 1R-0739, air 131-8821/131-8822, return 179-9806, pilot 5I-8670, case drain 093-7521), the 320D fuel filter page covers the combined fuel side, and the 320D radiator 326-3870 page covers cooling. For the practical side of keeping a fuel system clean — symptoms of a blocked element, separator service and the traps that send the wrong part — read our guide to excavator fuel filter problems.

FAQ

Q: Which machines use the Caterpillar 1R-0751 fuel filter?
A: Cat's 320D parts reference guide lists the 1R-0751 fuel filter element for the standard 320D, the 320D L and the 320D GC with the C6.4 engine. Aftermarket fitment lists extend the same element to the wider 3116/3126/3126B/C6.6/C7/C9 machine family — 320B and 320C excavators, 312C/312D, 323D L, 325C L, 953C/963C track loaders, D5M/D6K/D6M/D6N dozers, 120H/120K/140K/12K graders and 950G/962G loaders. Confirm by the number stamped on your old element.

Q: Is 1R-0751 the same as 1R-0750 or 1R-0749?
A: No. All three are Cat advanced-efficiency diesel fuel elements, but they are not interchangeable. The 1R-0750 is the 1"-14 element for the C10–C18 engine class (330D/336D machines among them), the 1R-0749 is a 3406/C10–C18 class element, and the 1R-0751 is the 7/8"-14 element listed for the 320D's C6.4 and the 3116/3126/C6.6/C7/C9 family. Match the number stamped on the element you remove.

Q: What does the 1R-0751 fuel filter cross-reference to?
A: Cross-reference lists pair 1R-0751 with Fleetguard FF5324 (FF5309 and FF5321 appear on some lists), Baldwin BF7632 (BF7530MPG, BF7634), Donaldson P551315, WIX 33377/33626, NAPA 3377/3626 and Fram P8264/P8451/P8490; the Cat numbers 1R-0759 and 6I4783 appear on the same fitment lists, and some suppliers list Cat 306-9199 as an equivalent. Cross numbers vary slightly between suppliers — treat them as a starting point and confirm the physical fit.

Q: Is this fuel filter OEM or aftermarket, and how do I order it?
A: This is a high-quality aftermarket fuel filter element cross-referenced to Caterpillar OEM 1R-0751, typically priced 30–60% below OEM list. Message us on WhatsApp or email sales@cn-machinery.com with your machine model, serial and the number on your old element — stock items dispatch in 3–7 days, FOB Shanghai or CIF to your port.