Sierra 18-6771 Tilt/Trim Reservoir, Replaces Mercury Marine 18525A1, 17646, White, Universal Fit

The Sierra 18-6771 is a tilt/trim fluid reservoir built as a direct replacement for Mercury Marine and Mercruiser tilt/trim systems. It stores and supplies the hydraulic fluid used by the power trim pump to raise and lower the outdrive, and it is designed to meet or exceed the quality of the original equipment part it replaces. The reservoir is molded from durable plastic in white and features a tank-mount design with threaded inlet and hose/pipe outlet connections, each sized at 0.38 inches, using NPT connectors for a secure, leak-resistant fit. This is a universal-fit reservoir, sized to fit the mounting footprint and connection style used across a range of Mercury Marine and Mercruiser trim pump assemblies. At 9.75 x 4.75 x 1 inches and 0.83 pounds, it is a straightforward, lightweight component for anyone servicing a trim system that has a cracked, leaking, or degraded original reservoir. It directly replaces Mercury Marine part numbers 18525, 18525A1, and 17646, so it drops into applications originally equipped with those reservoirs without modification. Each Sierra reservoir is manufactured to meet or exceed OEM specifications, giving boat owners and marine technicians a reliable, same-spec alternative to sourcing an increasingly hard-to-find original part.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-6771
• Product Type: Tilt/Trim Reservoir
• Color: White
• Material: Plastic
• Dimensions: 9.75 x 4.75 x 1 inches
• Weight: 0.83 pounds
• Inlet Connection Type: Threaded
• Inlet Connection Size: 0.38 inches
• Outlet Connection Type: Hose or Pipe Connection
• Outlet Connection Size: 0.38 inches
• Connector Type: NPT
• Mounting Type: Tank Mount
• Fit Type: Universal Fit
• UPC: 808282259501

Fitment

Universal fit for tilt/trim systems using the same reservoir mounting and connection style as the OEM numbers listed below.

Replaces (OEM)

• 18525
• 18525A1
• 17646

Frequently Asked Questions

What does the Sierra 18-6771 reservoir replace? The Sierra 18-6771 is a direct replacement for Mercury Marine tilt/trim reservoir part numbers 18525, 18525A1, and 17646.

What color is the 18-6771 tilt/trim reservoir? It is molded in white plastic, matching the appearance of the original Mercury Marine reservoir it replaces.

What are the dimensions of this reservoir? The Sierra 18-6771 measures 9.75 x 4.75 x 1 inches, sized to match the mounting footprint of the OEM reservoir it replaces.

How much does the 18-6771 weigh? This reservoir weighs 0.83 pounds.

What material is the reservoir made from? The 18-6771 is made from plastic, designed for durability in a marine tilt/trim fluid environment.

What size are the inlet and outlet connections? Both the inlet and outlet connections on the 18-6771 are 0.38 inches, using NPT threaded fittings; the inlet is threaded and the outlet accepts a hose or pipe connection.

Is this a genuine Mercury Marine part or an aftermarket replacement? The 18-6771 is a Sierra-manufactured aftermarket reservoir engineered to meet or exceed the specifications of the original Mercury Marine 18525A1, 18525, and 17646 reservoirs.

Does the Sierra 18-6771 fit my Mercruiser trim system? It is a universal-fit reservoir intended for tilt/trim systems that originally used Mercury Marine reservoir numbers 18525, 18525A1, or 17646.

How is the 18-6771 reservoir mounted? This reservoir uses a tank-mount design consistent with the original equipment reservoir it replaces.

What is included when I order part number 18-6771? The order includes one Sierra 18-6771 tilt/trim reservoir; it does not include the pump motor or pump assembly, which are separate parts.

Can I use the 18-6771 with a different pump motor, like the Sierra 18-6772? The 18-6771 reservoir is a standalone component that supplies fluid to the trim pump motor; it is a separate part number from pump motors such as the 18-6772 and pump assemblies such as the 18-6768.