Your FASS pump takes a Baldwin BF7633 or Wix 33528 on the water separator side, and a Fleetguard FS1000 or Wix 33522 on the fuel filter side, as long as you’re running a 1″-14 thread Titanium or Platinum series. HD and 150 Series pumps thread 1½”-16 and pull completely different part numbers. That covers the fast swap. The trickier part is knowing which can do which job, why the newer XWS-3002 and PF-3001 pair cannot be mixed with legacy elements, and which micron rating actually protects a common rail engine. The FASS fuel filter cross-reference tables below sort all of it out.
Quick Answer: Which Filter Replaces Your FASS Unit?
If you’re dealing with the water separator stage on Titanium and Titanium Signature pumps (FF-3003, FF-3010, XWS-3002), a Baldwin BF7633, Wix 33528, or Donaldson P553203 will get you out of a jam. And for the fuel filter stage (FS-1001, FS-1020, PF-3001), a Fleetguard FS1000, Wix 33522, or Donaldson P551000 does the job. Thread size across this group is 1″-14. HD and 150 Series pumps use a 1½”-16 thread and need different filters entirely.
A common trap for owners: FASS’s naming puts “FF” on the water separators and “FS” on the fuel filters. Since that seems backwards to most people, get in the habit of matching by function — what the filter does — rather than by its letters.
How to Identify Your FASS Filter Series
Before you make any FASS fuel filter cross-reference swap, double-check what’s actually in your hands. A filter can look like the right one and still have the wrong thread pitch or a micron rating that doesn’t match — and that’s all it takes for unfiltered diesel to reach your injection pump.
Check the Thread Size First
Three thread patterns cover almost every FASS pump on the road:
- 1″-14 thread: Titanium Series, Titanium Signature Series, and Platinum Series. Covers FF-3003, FS-1001, FS-1020, FF-3010, XWS-3002, and PF-3001.
- 1½”-16 thread: HD Series and older 150 Series. Covers FF-1003, FF-1010, and XWS-1002.
- ¾”-16 thread: Older 95 Series blue-body pumps with the discontinued FS-2001.
Spin the old filter off and compare the threads with a known good replacement before you commit. A loose seal here means fuel bypass.
Read the Part Number on the Housing
The FASS code is printed on the filter can. If you’re running a 1″-14 system, FF-3003 and FF-3010 handle water separation, and FS-1001 and FS-1020 are the fuel filters. On the newer platform, those same jobs are split across XWS-3002 (water separator) and PF-3001 (particulate fuel filter). Either way, nailing down what each can actually do is the one step you can’t skip before shopping a FASS fuel filter cross-reference.
Match Micron Rating Carefully
Water separators run finer, usually 2 to 6 microns. Fuel filters sit coarser, between 10 and 20 microns. Stay within one micron step of the original when possible. Going too coarse on the separator lets contaminants through. Going too fine on the fuel stage can starve the lift pump.
Keep in mind that FASS lists micron values as nominal ratings on its official cross-reference. The filter maker may publish a different number for the same part. Baldwin BF7633, for example, appears as 2M on the FASS sheet but Baldwin itself rates it at 4 micron absolute. Donaldson P553203 appears as 3M on the FASS sheet while Donaldson rates it at 4 micron at 99% efficiency. Both figures describe the same filter from different measurement perspectives.
Legacy Cross Reference Tables
The tables below cover 1″-14 thread legacy filters. These cover most trucks and tractors on the road today. Use them for emergency swaps and return to a genuine filter at the next scheduled service.
Water Separator Replacements (FF-3003, FF-3010, XWS-3002, XWS-3002XL)
The FASS official sheet organizes the water separator section into two columns. The left column lists pure water separator elements. The right column lists fuel/water separators with a drain port that FASS also accepts in the water separator position. Both groups are listed below.
Pure water separator elements:
| Replacement Filter | Micron Rating |
|---|---|
| Baldwin BF7633 | 2M |
| Carquest 86528 | 2M |
| CAT IP2299 | 6M |
| CAT 1R-0750 | 2M |
| Donaldson P551025 | 4M |
| Donaldson P551311 | 3M |
| Donaldson P553203 | 3M |
| Donaldson P557440 | 6M |
| Donaldson FF5320 | 2M |
| Hastings FF1079 | 2M |
| Fram P8334 | 2M |
| Wix 33352 | 6M |
| Wix 33528 | 2M |
| Wix 33674 | 2M |
Fuel/water separators with drain (also valid in this position):
| Replacement Filter | Micron Rating |
|---|---|
| Baldwin BF1258 | 10M w/drain |
| Baldwin BF1259 | 10M w/drain |
| Baldwin BF7546 | 9M w/drain |
| Baldwin BF-970 | 10M |
| Donaldson P551000 | 10M w/drain |
| Donaldson P551001 | 10M w/drain |
| Fleetguard FS1000 | 10M w/drain |
| Fleetguard FS1001 | 10M w/drain |
| Fleetguard FS1009 | 10M w/drain |
| Fleetguard FF-185 | 8M |
| Hastings FF-984 | 10M |
| Hastings FF-1060 | 10M w/drain |
| Luber-Finer LFF8000 | 14M w/drain |
| Wix 33405 | 14M w/drain |
| Wix 33406 | 5M w/drain |
| Wix 33522 | 10M w/drain |
For modern common rail injection, lean toward the 2 or 3 micron options in the first table. A 6 to 14 micron water separator replacement will get you home but should not stay on long term.
Note on part spelling: the FASS official sheet prints “CAT IP2299” with a leading letter I. Some catalogs list this as “1P2299” with a leading numeral. Both references point to the same Caterpillar part on the FASS cross table.
Fuel Filter Replacements (FS-1001, FS-1020, PF-3001, PF-3001XL)
| Replacement Filter | Micron Rating |
|---|---|
| Baldwin BF1212 | 20M |
| Baldwin BF1214 | 20M |
| Donaldson P551000 | 10M |
| Donaldson P558000 | 20M |
| Fleetguard FS1212 | 20M |
| Fleetguard FS1214 | 20M |
| Fleetguard FS1282 | 14M |
| Motorcraft FD818 | 14M |
| Wix 33522 | 10M |
If you tow heavy or run a tuned engine, pick a filter with a drain port from the water separator table above. It saves you from pulling the housing just to clear water that settles at the bottom.
Larger Thread Options for HD and 150 Series (FF-1003, XWS-1002)
| Replacement Filter | Micron Rating |
|---|---|
| Baldwin BT372-10 | 5M |
| Baldwin BT372-MPG | 10M |
| Carquest 85724 | 10M |
| Caterpillar 3T8642 | 5M |
| Cim-Tek 70032 | 10M |
| Cim-Tek 70213 | 3M |
| Donaldson P551313 | 3M |
| Donaldson P569381 | 3M |
| Fleetguard FF5588 | 10M |
| Fleetguard HF6338 | 10M |
| Fleetguard HF6601 | 10M |
| Fleetguard HF6604 | 3M |
| Fram P8024 | 5M |
| Hastings HF779 | 5M |
| Luber-Finer LFH4922 | 10M |
| Luber-Finer LFH8324 | 3M |
| Purolator 7400SAL032F2 | 3M |
| Wix 51116 | 11M |
| Wix 51120 | 9M |
| Wix 51202 | 5M |
| Wix 51724 | 10M |
These larger cans move more fuel and handle longer service intervals, which is why fleet and farm operators prefer them for continuous duty.
Current Generation vs. Legacy: Don’t Mix Them
FASS moved to a two-stage design that pairs the XWS-3002 water separator with the PF-3001 particulate filter. The two elements work only as a set, and they reverse their positions compared with the old setup. This catches many owners by surprise.
Key differences to respect:
- Position swap: The XWS-3002 sits on the pressure side, while the PF-3001 sits on the suction side. On legacy pumps, the arrangement was the opposite.
- Mandatory pairing: XWS-3002 only works with PF-3001. The XL versions pair with each other. Mixing a new element with a legacy element breaks the design.
- Micron ratings: XWS-3002 is a 2-micron absolute water separator with no drain port. PF-3001 is a 144-micron metal mesh strainer that catches larger debris before the pump.
A word of caution on cross-referencing: the XWS-3002 shares its filter group with the legacy FF-3003 and FF-3010, so aftermarket options — Baldwin BF7633, Wix 33528, Donaldson P553203 — can physically fit in its place. Fine for a short-term emergency, but that’s it. The full two-stage filtration logic depends on the matched XWS and PF pair.
A compact comparison of the two generations:
| Attribute | Legacy FF-3003 + FS-1001 | New XWS-3002 + PF-3001 |
|---|---|---|
| Water separator part | FF-3003 (pressure side) | XWS-3002 (pressure side) |
| Fuel filter part | FS-1001 (suction side) | PF-3001 (suction side) |
| Water separator rating | 2 to 6 micron | 2 micron absolute |
| Fuel filter rating | 10 to 20 micron | 144 micron mesh |
| Drain port | Yes on FS-1001 group | None on XWS-3002 |
For planned maintenance, it pays to stock genuine FASS replacement filters that match your exact pump generation. Treat any FASS fuel filter cross-reference swap as a backup plan rather than a long-term fuel strategy.
Best Practices for Filter Changes
A clean install matters as much as the right part number. Rushed swaps are a common cause of air intrusion, long cranks, and premature lift pump failure.
Follow this sequence every time you service the system:
- Drain the water separator before removal to limit spillage.
- Pre-fill the new filter with clean diesel to shorten the priming cycle.
- Inspect the O-rings and sealing surface on the housing for nicks or debris.
- Hand-tighten only on spin-on cans, then snug a quarter turn more.
- Prime the system with the FASS primer or the key cycle method before cranking.
- Log the date and hours so the next service does not sneak up on you.
Plan swaps around fuel quality, not just the calendar. Dusty job sites, biodiesel blends, and long storage periods all shorten filter life. Carry a spare set of high-flow diesel fuel filters in your toolbox if you work away from paved roads often. One restricted filter at the wrong moment can leave you stranded.
Watch for these signs that a filter is near end of life:
- Hard starts or long cranks after sitting overnight
- Power loss under load, especially on grades
- Visible debris or dark fuel in the bowl
- Water collection in the separator between services
- Pressure drop warnings on gauge-equipped pumps
Any of those symptoms means the next change should happen now, not later. Running a tired element on a high-pressure common rail engine is one of the quickest ways to send metal through the fuel system.
Final Thoughts
Stock genuine filters for routine service and lean on this FASS fuel filter cross-reference only when the shelf runs dry. Confirm the thread, hold the micron rating close to spec, and keep legacy elements away from the XWS-3002 and PF-3001 pair. FridayParts stocks aftermarket FASS replacement filters across Baldwin, Wix, Donaldson, Fleetguard, and Hastings numbers at fair pricing, with coverage for Titanium, Platinum, HD, and 150 Series pumps. One correct filter, properly primed and torqued, is the cheapest insurance a diesel owner ever buys.
