FM100 Fuel Filter Assembly 30-Micron — Universal Diesel Primary Filtration
The FM100 Fuel Filter Assembly (30-Micron) is a heavy-duty primary fuel filter designed for diesel engines using the FM100 series filter system. This complete assembly replaces OEM part numbers 42093, 31863, and BF7783-D, delivering reliable 30-micron filtration to protect your injection pump and injectors from water, dirt, and debris. The kit includes 2 hose tail fittings and 2 plugs for straightforward installation.
Key Features
Universal FM100 Compatibility: Engineered to fit all standard FM100 series filter heads — drop-in replacement for Donaldson, Fleetguard, Baldwin, and other FM100 housings.
30-Micron Primary Filtration: Ideal as a first-stage water separator and particulate filter. Removes rust, scale, and free water before fuel reaches the secondary (final) filter.
Complete Assembly Kit: Includes the filter element, 2 hose tail fittings (for 3/8" and 1/2" fuel lines), and 2 plugs — everything needed for a standard installation.
High-Efficiency Media: Cellulose-blended filter media with hydrophobic treatment repels water while trapping solid contaminants. Rated for diesel, biodiesel blends up to B20, and heating oil.
Industrial-Grade Construction: Heavy-duty steel end caps and reinforced center tube withstand high fuel flow rates and pressure differentials in demanding diesel applications.
Compatibility
Filter Series
FM100 (Donaldson / Fleetguard / Baldwin)
Replaces OEM Part Numbers
42093, 31863, BF7783-D, BF7783D, P550588, FS19815
Filtration Rating
30 Micron (Nominal)
Application
Primary (first-stage) fuel filtration / water separation
Media Type
Cellulose-blended with hydrophobic treatment
Included Fittings
2× Hose Tail Fittings (3/8" & 1/2"), 2× Plugs
Vehicles & Equipment that Use FM100 Filters
The FM100 filter head is one of the most widely used diesel filtration platforms, found on:
Agricultural tractors and combines (John Deere, Case IH, New Holland)
Construction and mining equipment (Caterpillar, Komatsu, Volvo CE)
Marine diesel engines (Yanmar, Volvo Penta, Cummins Marine)
Stationary generators and pump sets
Over-the-road trucks using remote fuel filter mounts
Custom diesel conversions and fuel polishing systems
Technical Specifications
Part Number
FJ-31863-ZH (iFJF)
OEM Cross-Reference
42093, 31863, BF7783-D, BF7783D, P550588, FS19815, FF5320
Filter Type
Spin-On, Primary Fuel Filter / Water Separator
Micron Rating
30 Micron Nominal
Thread Size
1"-14 UNS (standard FM100 thread)
Outer Diameter
Approx. 3.7 inches (93 mm)
Overall Height
Approx. 5.5 inches (140 mm)
Gasket
Nitrile (Buna-N) — fuel-resistant
Service Interval
Every 500 hours or annually — drain water bowl monthly
Why Choose iFJF FM100 Fuel Filter Assembly?
Precision-Engineered: Manufactured to IATF 16949 quality standards with 100% end-of-line leak testing.
Complete Kit: Unlike bare filter elements, this assembly includes the fittings and plugs you need for a typical installation — no extra trips to the parts store.
Cost-Effective Protection: A $110 filter assembly protects a fuel injection system that can cost $3,000-$10,000 to rebuild. It's the cheapest insurance you'll ever buy for your diesel engine.
USA-Based Support: iFJF Direct ships from US warehouses with fast delivery and responsive customer service.
Installation Tips
Shut off the fuel supply and relieve system pressure before removing the old filter.
Place a drain pan under the filter housing — expect 0.5-1 quart of fuel spillage.
Use a strap wrench or filter wrench to remove the old spin-on filter (turn counterclockwise).
Clean the filter head mounting surface and apply a thin film of clean diesel fuel to the new gasket.
Hand-tighten the new filter until the gasket contacts the mounting surface, then tighten an additional 3/4 to 1 turn — DO NOT overtighten.
Install the appropriate hose tail fittings or plugs based on your fuel line configuration.
Prime the fuel system using the manual primer pump (if equipped) or by cycling the ignition key 3-5 times.
Start the engine, check for leaks, and re-torque if necessary.
Frequently Asked Questions
Q: Will this fit my FM100 filter head?
A: Yes. This assembly uses the standard 1"-14 UNS thread pattern common to all FM100 series filter heads, including Donaldson, Fleetguard, Baldwin, and most aftermarket housings. If your existing filter has a 1" center thread, it will fit.
Q: What's the difference between 30-micron and 10-micron filtration?
A: The FM100 30-micron filter is designed as a primary (first-stage) filter — it removes larger particles and free water before fuel reaches the secondary fine filter. Most diesel systems use a 30-micron primary + 2-10 micron secondary setup. Using only a 10-micron filter as primary can cause premature clogging and fuel restriction.
Q: Does the FM100 filter head have a water drain?
A: Some FM100 housings include a built-in water drain valve at the bottom; others require periodic filter replacement to remove accumulated water. Check your specific housing. If equipped with a drain, open it monthly to drain any separated water.
Q: How often should I replace the FM100 filter?
A: Under normal conditions, replace every 500 operating hours or annually, whichever comes first. In dusty, high-humidity, or heavy-load applications, reduce the interval to 250-300 hours. Always drain the water bowl (if equipped) monthly.
Q: Can I use this filter with biodiesel?
A: Yes, compatible with biodiesel blends up to B20. For blends above B20, more frequent filter changes are recommended as biodiesel has stronger solvent properties that can release accumulated deposits from fuel tanks and lines.
Q: Do the included fittings fit my fuel lines?
A: The kit includes hose tail fittings for 3/8" and 1/2" ID fuel hoses — the two most common sizes for diesel fuel systems. The included plugs cover unused ports. If you need a different size, standard JIC or SAE fittings can be sourced locally.
Q: What happens if I don't change the primary fuel filter?
A: A clogged primary filter restricts fuel flow to the injection pump. Symptoms include hard starting, loss of power under load, engine surging, and eventually — no-start conditions. Worst case: the pump runs dry, overheats, and fails. A $110 filter protects thousands in injection system components.
Q: Is this filter the same quality as OEM?
A: Yes. iFJF filters are manufactured to IATF 16949 standards with the same filtration media specifications as OEM FM100 filters. We use the same cellulose-blended media with hydrophobic treatment. Every filter undergoes end-of-line leak and burst testing before shipment.
Protect your injection system with the filter the pros trust. Order today and get fast US shipping from iFJF Direct.
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