Sierra Fuel Filter 18-7846 — Medium 21-Micron, 1"-12 Thread Universal Replacement

The Sierra International 18-7846 Medium Fuel Filter is a 21-micron, 1"-12 threaded replacement designed to match common OEM marine and automotive fuel filters for reliable contamination control.

This replacement fuel filter from Sierra fits a wide range of engines and fuel systems where a medium 21-micron filtration rating is specified. Built as a universal-fit unit, it is compatible with several OEM part numbers — including Crusader 98041 and OMC 502905 — offering a straightforward swap for maintenance and repair jobs. The part is covered by Sierra's customer satisfaction warranty, giving installers and boat owners added confidence when servicing fuel systems.

How does this filter match OEM specifications?

The 18-7846 is engineered to replicate critical dimensions and thread pitch for direct compatibility with many original equipment applications. It uses a 1"-12 thread pitch and a 21-micron media rating to meet the same basic filtration and fastening requirements as the referenced factory parts.

• Direct replacements: Crusader 98041, OMC 502905, OMC 174144
• Equivalent OEM numbers: Volvo 3851218-2
• Thread pitch: 1"-12 for secure mounting
• Filtration rating: 21 micron for medium contaminant capture

What are the key technical features I should know?

This medium fuel filter combines a defined particle rating with standard mechanical fittings so it can be installed without modifying the fuel system. The construction and materials are selected for typical marine and automotive operating environments.

• Filter rating: 21 micron to trap medium-sized particles
• Thread pitch: 1"-12 to match common housings and adapters
• Fit type: Universal fit for flexible application across models
• Warranty: Covered under Sierra's customer satisfaction policy

When should I choose a 21-micron filter like this?

Choose this medium-grade filter when the manufacturer's service specifications call for 21-micron filtration or when replacing the listed OEM part numbers. It balances contaminant protection with fuel flow, making it suitable for routine maintenance intervals on many gasoline and diesel systems.

• Ideal for scheduled filter replacements that cite 21 micron
• Appropriate when replacing listed OEM numbers to maintain system specs
• Useful where moderate particulate removal is needed without excessive flow restriction

Who is this for: The Sierra 18-7846 is intended for boat owners, mechanics, and fleet service technicians who need a reliable, direct-fit replacement for mid-grade fuel filtration. It’s well suited to those servicing older or mixed-brand marine engines and vehicles that list Crusader 98041, OMC 502905/174144, or Volvo 3851218-2 as compatible parts. If you require a sturdy, warranty-backed medium filtration element with a standard 1"-12 thread, this filter offers a practical and cost-effective option for routine maintenance and repairs.