AirDog WS100 & FF100-2 Replacement Pre-Filter and Fuel Filter Combo Pack — Fits AirDog/II/II-4G, Water-Separating

AirDog Pre-Filter WS100 and Fuel Filter FF100-2 Combo Pack are replacement water separator and fuel filter elements designed to restore fuel flow and moisture protection for AirDog fuel filtration systems.

These Pureflow replacement elements fit AirDog, AirDog II and AirDog II-4G systems and are made to remove water and particulate that reduce diesel fuel pressure and injector performance. Regularly replacing the pre-filter (WS100) and the fuel filter (FF100-2) keeps the filtration system operating at peak capacity and reduces the risk of clogged lines, stalled injectors, and reduced engine responsiveness. This listing includes the filter elements only and does not include the full AirDog pump assembly.

How do these replacement filters improve diesel fuel flow?

The WS100 pre-filter captures free water while the FF100-2 fuel filter traps fine particulates and contaminants before they reach the engine. Replacing both at recommended intervals prevents pressure drops and restores consistent fuel delivery to the injection system.

• WS100 removes separated water to prevent corrosion and microbial growth.
• FF100-2 captures soot, rust, and dirt to protect injectors and pumps.
• New elements help maintain factory flow rates and pressure stability.

When should I change the pre-filter and fuel filter?

Replacement frequency depends on fuel quality and operating hours, but inspect filters during routine service intervals or if you notice lower fuel pressure. As a general practice, change filters at the first sign of reduced engine performance, increased fuel pump noise, or visible contamination in the filter housing.

• Check seals and elements during scheduled maintenance or every few thousand miles/hours.
• Replace immediately after discovering water or heavy sediment in the system.
• Follow vehicle or equipment manufacturer recommendations for interval guidance.

Are these parts compatible with my AirDog model?

Yes — these Pureflow WS100 and FF100-2 elements are designed to fit AirDog, AirDog II and AirDog II-4G filtration units. They are intended as direct replacements for the original water separator and fuel filter elements in those systems.

• Direct-fit replacements for AirDog, AirDog II, and AirDog II-4G series.
• Sold as filter elements only; pump housings and fittings are not included.
• Verify part numbers against your system manual before purchase.

What should I expect during installation and maintenance?

Installing the WS100 and FF100-2 elements is a straightforward service task for most technicians and experienced DIYers familiar with fuel systems. Use clean tools, replace O-rings if worn, and prime the system after installation to remove trapped air.

• Drain water from the separator before element removal to avoid spills.
• Replace associated seals and tighten to manufacturer torque specs.
• Prime the AirDog pump per instructions to restore proper fuel flow.

Who is this for: This combo pack is aimed at diesel vehicle owners, fleet managers, and marine or industrial operators running AirDog filtration systems who want to maintain reliable fuel delivery and protect injectors and pumps. Choose this set when you need proven replacement elements that restore moisture separation and particulate filtration without replacing the entire pump, especially if you run varied fuel sources or operate in humid or contaminated-fuel environments.

• Fuel Type: Diesel
• Includes: AirDog-compatible water separator (WS100) and fuel filter (FF100-2) replacement elements
• Note: This listing is for replacement elements only — does NOT include the AirDog pump or full fuel system