For MerCruiser Sea Water Pump Assembly - P/N: 46- 8M0139996

Sea Water Pump Assembly for MerCruiser

This sea water pump assembly replaces MerCruiser P/N 46-8M0139996, moving raw water through the cooling system to keep engine temperatures in check on the water.

Overview

This sea water pump assembly is the raw water pump for MerCruiser marine engines, drawing water from the lake or sea and pushing it through the heat exchanger and exhaust. It is made for boat owners and marine mechanics who need a reliable replacement for a leaking or seized pump. The assembly cross-references MerCruiser P/N 46-8M0139996, so it drops into the same mounting location as the original unit.

Built For Performance

• Complete pump assembly with housing, impeller, and seal already fitted
• Corrosion-resistant housing built for continuous raw water exposure
• Flexible impeller that keeps flow steady across the RPM range
• Precision-machined bore for a proper seal against water bypass
• Direct mounting match to the MerCruiser pump bracket

On-The-Job Use

• Replacing a raw water pump that leaks or stops priming
• Scheduled impeller service on sterndrive and inboard setups
• Keeping coolant temperatures stable during long runs
• Seasonal maintenance before launching for the year

Specs At A Glance

Good To Know

Q: Does this sea water pump assembly come with the impeller installed? A: Yes, the assembly ships complete with the impeller and seals in place, so it is a bolt-on replacement. Inspect the impeller at the start of each season and replace it if the vanes show cracks or a set.

Q: Can I install this without pulling the whole engine? A: On most MerCruiser setups the pump is accessible from the front of the engine without removal. Always confirm your engine and drive combination matches P/N 46-8M0139996 before starting the job.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.