Fuelab 85831-3 858 Series In-Line Fuel Filter with Integrated Check Valve Long Length 6 Micron

The Fuelab 858 Series In-Line Fuel Filter (85831-3) combines high-flow filtration with an integrated check valve in a single, compact billet aluminum housing. Featuring a long-length, 5-inch 6-micron micro-fiberglass element and -8AN male inlet/outlet connections, this filter is engineered for performance fuel systems demanding precise filtration and sustained fuel pressure.

The integrated check valve allows your fuel system to maintain fuel pressure after engine and pump shutdown, helping to prevent vapor buildup in the fuel rails during engine cooling. Because the check valve is housed within the filter body itself, it is fully protected by the filter element — eliminating the need for a separate check valve component and additional fittings.

Key Features:

• 6-Micron Micro-Fiberglass Element — Fuelab's most advanced filter media; provides superior particle protection and reduced maintenance frequency. Disposable (not cleanable).
• Integrated Check Valve — Maintains fuel pressure post-shutdown and protects against vapor lock in fuel rails
• -8AN Male Inlet/Outlet — Connects directly to AN-style fuel system components without additional adapters
• Long Length / 5-Inch Element — Increased filtration capacity and extended service intervals vs. standard-length filters
• Billet Aluminum Housing — Military-spec anodized finish (MIL-A-8625, Type II) for corrosion resistance and durability
• Machined Internal Radii — Minimizes pressure drop for maximum fuel flow; supports up to 200 GPH
• Multi-Fuel Compatible — Suitable for gasoline, diesel, ethanol (E85), and methanol fuel systems
• 200 PSIG Maximum Pressure Rating — Compatible with high-pressure EFI and forced induction fuel systems
• Includes low-profile saddle clamp mounting bracket
• Limited Lifetime Warranty

The Fuelab 85831-3 is sold individually and backed by Fuelab's limited lifetime warranty, making it a reliable long-term investment for race, street performance, and high-output fuel system builds.