Sierra 18-3087 Water Pump Impeller for MerCruiser Sterndrive Engines

The Sierra 18-3087 is a premium-quality replacement water pump impeller designed for MerCruiser stern drive engines with engine-mounted sea water pumps manufactured in 1999 and older. This impeller is the heart of your engine's cooling system, ensuring proper water flow to prevent overheating and maintain optimal engine performance.

Key Specifications:

• Outside Diameter: 2.595 inches
• Bore: 0.750 inch with single flat spot
• Thickness: 2.010 inches
• 8 flexible blades for efficient water pumping
• Round key design
• Weight: 0.81 lbs

OEM Cross-References:

• MerCruiser: 47-59362, 47-59362T1, 47-593621, 47-59362A1
• GLM: 89740
• Mallory: 9-45375, 9-45375-10

Sierra impellers are manufactured to stringent quality standards and are fully interchangeable with original equipment manufacturer parts. Regular inspection is recommended annually, with replacement suggested every three years or more frequently in saltwater applications or with excessive use. Note that the impeller and water pump shaft feature a single flat spot for proper alignment during installation.