Part Number: 47-35992
Sierra 18-3599-2 Circulating Water Pump
Keep your engine running at the proper temperature with the Sierra 18-3599-2 Circulating Water Pump. Designed as a high-quality replacement for select OEM marine cooling systems, this bi-directional circulation pump helps maintain consistent coolant flow throughout the engine block for dependable performance on the water.
Unlike a raw water pump, the circulation pump continuously moves coolant through the engine to regulate operating temperature and prevent overheating. A worn or failing pump can lead to coolant leaks, noisy bearings, unstable temperatures, or restricted circulation that can quickly turn into costly engine damage if ignored.
The Sierra 18-3599-2 is built using durable marine-grade materials and engineered to meet or exceed OEM specifications for fit, performance, and reliability. Its bi-directional design allows compatibility with both standard and counter-rotating engines, making it a versatile replacement option for many popular marine applications.
Common Engine Fitments
The Sierra 18-3599-2 circulation water pump is commonly used on GM-based marine engines, including:
- MerCruiser 4.3L V6
- MerCruiser 5.0L V8
- MerCruiser 5.7L V8
- MerCruiser 6.2L MPI (377 CID)
- PCM GM small block V8 engines
- Crusader 305 and 350 CID engines
- Volvo Penta GM small block V6 and V8 applications
These engines are frequently found in boats such as:
- Sea Ray Sundancer and Sport series
- Chaparral SSi and Signature models
- Four Winns Horizon series
- Malibu Response and Sunsetter
- Supra Launch and Sunsport models
- Correct Craft Ski Nautique and Super Air Nautique
Fitment depends on engine rotation, timing cover style, and cooling system configuration, so confirming compatibility with part number 18-3599-2 before ordering is recommended.
Key Features
- Bi-directional marine circulation water pump
- Designed for GM V6 and small block V8 engines
- Helps maintain proper engine operating temperature
- Compatible with standard and counter-rotating applications
- Marine-grade construction for durability and long service life
- Direct replacement for select MerCruiser, PCM, Crusader, and Volvo Penta engines
Why Replace a Circulation Water Pump?
Over time, pump bearings and seals can wear from heat and constant operation. Replacing a failing circulation pump helps restore proper coolant flow, stabilize engine temperature, and protect critical engine components from overheating damage.
If you’re servicing a GM-based marine engine, the Sierra 18-3599-2 circulation water pump delivers dependable cooling performance and OEM-style reliability trusted across a wide range of inboard and sterndrive applications.