AN 5278 Aftermarket Nanni 4.220HE Seawater Pump ST274, Johnson 10-24386-01 | Sawley's Select Marine Parts

🔧 Product Description

Aftermarket replacement 4.220HE Seawater Pump - Part Number: AN 5278

New aftermarket engine-cooling seawater pump for Nanni 4.220HE marine diesel engines using pump ST274. It replaces the listed OEM pump family and is supplied as a complete assembled pump. Match Nanni ST274 and Johnson 10-24386-01.

⚙️ Key Features

• Direct aftermarket replacement for AN 5278

• Heavy-duty marine-grade bronze or corrosion-resistant pump construction

• Engine-driven pump

• Port configuration: Engine-specific hose/pipe ports

• Serviceable flexible-impeller design with replaceable cover, cam, seal, shaft and bearings

🧰 Kit / Assembly Contents

• 1 × Complete seawater pump assembly - Part Number: AN 5278

• 1 × Installed impeller - Installed Johnson/DJ flexible impeller for the 10-24386-01 family

• 1 × Installed shaft, bearing, cam and mechanical-seal assembly

• 1 × Installed end cover with gasket or O-ring sealing system

• Mounting / installation: Confirm mounting flange and shaft

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• AN 5278 → Replaces / cross-references ST274

OEM / Related Numbers:

• ST274

Aftermarket / Verified Equivalents:

• Johnson Pump: 10-24386-01

• DJ Pumps: AN 5278

Service Parts / Kits:

• Minor repair and impeller kits available for the AN 5278 family

🚤 Compatibility

Commonly used on:

• DJ Pumps / Nanni / Johnson Pump marine engine-cooling systems

Typically suits:

• Engine models:

• Nanni 4.220HE marine diesel engines using pump ST274

• HP / Output Range: Engine- or generator-rating dependent

• Engine Type: Marine diesel, petrol or generator engine as listed above

• Year Range: Engine-model, arrangement and serial-number dependent

• Port / Drive Identification: Engine-specific hose/pipe ports; Engine-driven pump. Confirm rotation, shaft/gear style, flange, port direction and mounting seal before ordering.

🔌 Function

The engine-driven flexible-impeller seawater pump draws raw water through the vessel's intake and strainer, then circulates it through the heat exchanger, charge-air cooler, exhaust mixer and other seawater-cooled components. Adequate flow is essential for controlling engine and exhaust temperatures.

Common signs of failure:

• Engine or exhaust temperature rises above normal

• Weak or absent seawater discharge at the exhaust outlet

• Impeller blades are cracked, missing, swollen or permanently set

• Water leaks from the pump cover, shaft seal, drain hole or mounting flange

• Bearing noise, shaft play or a seized pump drive

📦 Condition

• New aftermarket replacement seawater pump

• Brand new

• Supplied in original or equivalent packaging