Sierra 18-7775-1 Fuel Water Separator Kit, 3/8 Inch Aluminum Bracket, Replaces Moeller 33320-10

The Sierra 18-7775-1 Fuel Water Separator Kit is a complete fuel filtration solution built to remove over 99.8% of emulsified water from gasoline before it reaches your engine. Designed to protect sensitive inboard, sterndrive, and outboard fuel injection systems, this kit supports a flow rate of 90 gallons per hour, keeping fuel delivery steady even under heavy demand.

The kit includes a universal-design, 3/8 inch aluminum fuel water separator bracket (Sierra Part Number 18-7775) that is precision machined and powder coated for corrosion resistance and long-term durability. It pairs with a long, 4.35 inch tall fuel water separator filter (Sierra Part Number 18-7845) rated at 21 microns, plus two 3/8 inch pipe plugs (Sierra Part Number 18-4264) for a complete, ready-to-install assembly.

This is a universal-fit kit suited to boat fuel systems, and it cross-references directly to Moeller 33320-10 and Mallory 9-37852, making it a straightforward replacement when those parts wear out or need upgrading. All components are covered under Sierra's Customer Satisfaction Warranty.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-7775-1
• Product Type: Fuel Water Separator Kit
• Bracket Material: Aluminum
• Bracket Design: Universal, precision machined, powder coated
• Filter Length: 4.35 inches
• Filter Micron Rating: 21
• Pipe Plug Thread Size: 3/8 inch
• Pipe Plug Quantity: 2
• Flow Rate: 90 gallons per hour (GPH)
• Water Removal Efficiency: Over 99.8% of emulsified water
• Weight: 2.29 pounds
• Vehicle Service Type: Boats
• Fit Type: Universal fit
• OEM Cross Reference: Mallory 9-37852, Moeller 33320-10

Fitment

This is a universal-fit kit for boat fuel systems, suitable for inboard, sterndrive, and outboard fuel injection applications. Verify compatibility with your specific fuel system before ordering.

Replaces (OEM)

Mallory 9-37852, Moeller 33320-10

Frequently Asked Questions

What is included in the Sierra 18-7775-1 kit? The kit contains one 3/8 inch aluminum fuel water separator bracket (Sierra Part Number 18-7775), one 4.35 inch tall fuel water separator filter (Sierra Part Number 18-7845), and two 3/8 inch pipe plugs (Sierra Part Number 18-4264).

Does this kit fit outboard and sterndrive engines? Yes, the 18-7775-1 kit is a universal-fit fuel water separator designed for use on inboard, sterndrive, and outboard fuel injection systems.

What OEM parts does the Sierra 18-7775-1 replace? It cross-references to Mallory 9-37852 and Moeller 33320-10, so it can be used as a direct replacement for either of those part numbers.

How much water can this filter remove from fuel? Over 99.8% of emulsified water is removed from gasoline by the filter included in the Sierra 18-7775-1 kit.

What is the flow rate of the Sierra 18-7775-1 fuel water separator? 90 gallons per hour is the rated flow, which is enough to feed high-demand fuel-injected marine engines.

What micron rating is the filter in this kit? The included fuel water separator filter (Sierra Part Number 18-7845) carries a 21 micron rating.

What material is the mounting bracket made from? The bracket (Sierra Part Number 18-7775) is precision-machined, powder-coated aluminum, chosen for corrosion resistance in marine environments.

How much does the Sierra 18-7775-1 kit weigh? The complete kit weighs 2.29 pounds.

Is the Sierra 18-7775-1 covered by a warranty? Yes, this kit is covered under Sierra's Customer Satisfaction Warranty against defects in workmanship and materials.

Is the Sierra 18-7775-1 bracket a universal design? Yes, the bracket included in this kit uses a universal design intended for broad compatibility across boat fuel systems.

How many pipe plugs come with this kit and what size are they? Two 3/8 inch pipe plugs (Sierra Part Number 18-4264) are included with the 18-7775-1 kit.

Why should I install a fuel water separator like the 18-7775-1? This kit is recommended to prevent damage to sensitive inboard, sterndrive, and outboard fuel injection systems by filtering emulsified water out of the fuel before it reaches the engine.