Fleetguard NEW OEM WF2126 Coolant Water Filter DCA4 15 Unit Cummins ISX X15 0810

Fleetguard Coolant / Water Filter — Part Number WF2126

Brand: Fleetguard | Condition: New Old Stock (NOS)

Genuine Fleetguard WF2126 spin-on coolant filter — the Extended Service coolant filter for Cummins' big-bore engines: Signature, ISX, ISXe5, ISM and X15. Fleetguard is Cummins' own filtration brand, so this is the original equipment filter, not a copy.

This filter carries 15 units of DCA4+ supplemental coolant additive in slow-release tablet form, on a borate nitrite base. Slow release is the important part: rather than dumping the whole inhibitor charge into the coolant at once, the tablet meters it in over the service interval, so the DCA level stays inside its correct band instead of spiking after a filter change and falling away before the next one.

Mechanically it strains scale, rust and casting debris out of the cooling system. Chemically it maintains the corrosion inhibitor level that protects wet cylinder liners from cavitation pitting — the failure mode that ends wet-liner diesel engines, and the reason the coolant filter exists at all on a Cummins big-bore.

Condition Details

New Old Stock — never installed, never used. This filter has been held in long-term parts inventory, so the box, wrapper or label may show shelf wear, dust, fading, denting or dated printing. The filter itself is new, unused and unopened, with the sealing gasket in place. Photos show the actual item you will receive.

Specifications

• Part number: WF2126 (also listed as FGWF2126)
• Fleetguard description: Water filter, spin-on
• Supplemental coolant additive: DCA4+, 15 units — per Cummins' own coolant and chemicals catalogue
• Service type: Slow release, Extended Service (ES) chemical
• Additive form: tablet
• Additive base: Borate nitrite
• Thread size: M36 × 2-6G INT — metric internal thread
• Overall height: 146.3 mm (5.76 in)
• Largest outside diameter: 93.73 mm (3.69 in)
• Seam outside diameter: 91.95 mm (3.62 in)
• Gasket outside diameter: 3.77 in
• Gasket inside diameter: 3.18 in
• Style: Spin-on
• Genuine Fleetguard / Cummins Filtration OEM — not aftermarket
• Sold as: one (1) filter

A note on the unit count. Cummins' own coolant and chemicals catalogue publishes WF2126 as 15 units DCA4+ slow release ES. One retailer lists it as 8 units. We have gone with Cummins' own figure. Unit count determines the cooling system capacity the filter suits, so if your service literature specifies a different figure, go by the literature.

Superseded & Cross Reference Part Numbers

Cummins: 3100310, 3680315, 3680433, 4907485 (service part 3958392S)
Baldwin: BW5086
Donaldson: P550866, P552125, P552126
Wix: 24111, 24112
Fram: PR8692, PR8693
Luber-Finer: LFW2126
Mann-Filter: WA9563
John Deere: PMWF2126
Case IH: 84477273
Ford: F7UZ17A605AE
Atlas Copco: 57929044
Ingersoll-Rand: 54662051

Cross references are provided as a guide; confirm against your own engine before purchase.

✅ Good news on identification: this filter will not interchange with the WF207x family. WF2074, WF2075, WF2076, WF2077 and WF2144 all use an 11/16-16 thread. WF2126 uses a metric M36 × 2 internal thread and a larger 3.18 / 3.77 in gasket. It physically cannot be fitted to those heads, or they to this one — so unlike the rest of the range, a mix-up here is self-correcting at install.

Features

• Genuine Fleetguard — the Cummins filtration brand. On a coolant filter the chemistry is the product, and DCA4+ is Cummins' own formulation
• 15 units of DCA4+ in slow-release tablet form, metered into the coolant across the service interval rather than released all at once
• Borate nitrite additive base, the inhibitor chemistry Cummins specifies for its wet-liner big-bore engines
• Protects wet cylinder liners from cavitation pitting — progressive, expensive, and entirely preventable with correct inhibitor maintenance
• Extended Service rating, designed for the long drain intervals these engines run
• Distinctive metric M36 × 2 thread, so it cannot be cross-fitted with the 11/16-16 coolant filters
• Big-bore Cummins installed base — Signature, ISX, ISM and X15 power an enormous share of North American Class 8 trucking plus industrial and compressor applications
• Consumable by design: a scheduled service item, so this is a repeat-purchase part with steady year-round demand

Application

Fits engines specifying a WF2126 coolant filter:

• Cummins Signature (including Signature 600)
• Cummins ISX and ISXe5
• Cummins X15
• Cummins ISM

Cross-referenced into the Case IH, John Deere, Atlas Copco and Ingersoll-Rand parts catalogues as well — the Atlas Copco and Ingersoll-Rand numbers indicate compressor and industrial packages running Cummins power.

Coolant filter selection depends on cooling system capacity and the coolant technology in use, and manufacturers change the specified filter across engine serial ranges. Please confirm WF2126 is the filter specified for your engine — by engine serial number, not chassis model — before ordering. Tell us the engine and serial and we are glad to help you check.

Why Choose Fleetguard?

Fleetguard is Cummins' filtration brand, which on a coolant filter matters more than on any other filter type. The DCA4+ additive package, the borate nitrite base, the slow-release tablet and the service interval were designed together by the company that built the engine. A filter that threads onto the head but carries a different inhibitor package, or the wrong number of units, will keep the coolant clean and still let the liners pit. On a Signature or an X15 the filter costs a fraction of a percent of what the engine costs, and it is protecting the liners.

Returns

We accept returns within 30 days of delivery through the eBay return request system. Items must be returned in the condition in which they were received.

Thank you for looking at our listing. We are a family-run parts business and we take real care in identifying, describing and packing every item we sell. Much of our inventory is genuine NOS dealer stock that simply is not available new any longer, and we are glad to see these parts go to people who still keep older equipment running properly.

If anything about this listing is unclear, if you would like additional photographs, or if there is any problem at all with your order, please contact us first and give us the chance to make it right before leaving feedback. We answer messages quickly and we will always work with you.

QBS Parts, Inc — Gardena, CA