SIERRA 18-3237 Raw Water Pump Impeller

Compatible Engines

The SIERRA 18-3237 raw water pump impeller is a critical component of the cooling system, engineered for reliability and extended service life. This part is specifically designed for MERCRUISER Bravo I, II, and III outboard and sterndrive engines manufactured from 1988 onwards. Please pay close attention to the engine serial number, as this impeller fits only units with serial numbers B664190 and newer. Due to the specific engineering of marine engines, precise fitment is paramount. Compatibility must always be verified by cross-referencing the manufacturer's catalog number 18-3237 with the original equipment (OE) number, or by consulting our support team to prevent installation errors.

Installation and Maintenance

• SIERRA Original Quality – Guarantees durability and strict adherence to engine manufacturer specifications.
• Perfect Fit – Precise dimensions (66.5x50.6x19 mm) ensure a tight seal and efficient water pumping.
• Easy Replacement – Simple design allows for quick repairs in standard workshop conditions.
• Engine Protection – Regular replacement prevents overheating and avoids costly mechanical failures.

Replacing the impeller is a standard maintenance task, recommended every season or after 100-150 hours of operation. Using low-quality spare parts can lead to leaks and reduced system pressure. Installing a SIERRA impeller is an investment in your safety and performance on the water.