Cummins QSL Marine Water Pump - Aftermarket

Marine Water Pumps & Cooling System Components for Cummins QSL Engines

When operating a Cummins QSL engine in marine environments, ensuring reliable and efficient cooling is essential for performance, longevity, and fuel efficiency. One of the most vital components of the marine cooling circuit is the raw water pump, also known as the seawater pump. This component is responsible for pulling in cool seawater and circulating it through the heat exchanger, aftercooler, and other engine components to prevent overheating. Diesel Pro Power offers a full line of Cummins QSL marine cooling parts, including raw water pumps, impellers, O-rings, gaskets, thermostats, intake strainers, hoses, and clamps—each tailored for marine durability and backed by our commitment to quality.

Raw Water Pumps for Cummins QSL Marine Engines

Whether you're replacing a worn-out pump or upgrading for increased durability, our selection of raw water pumps is engineered to meet or exceed Cummins' marine standards.

Bidirectional Marine Water Pump for Cummins QSL, QSB, and C-Series Engines

This pump features 11° offset mounting holes from the drive gear shaft center and supports bidirectional rotation, making it compatible with both left-hand and right-hand engine configurations. It comes with a 1 3/4” flange port, ensuring high flow for saltwater cooling systems.

Compatible with Cummins B, C, QSB, and QSL marine engines
Machined to precision for perfect fit and reduced vibration
Marine-grade materials resist corrosion from constant saltwater exposure

Cummins Marine Seawater Pump for QSC and QSL

Designed specifically for the Cummins QSC and QSL platforms, this raw water pump includes a pre-mounted O-ring for leak-free installation. It’s engineered for robust service in marine cooling systems, ensuring consistent seawater intake under variable load conditions.

Direct-fit for QSL and QSC marine engine applications
Manufactured to handle high RPMs and marine thermal loads
Saltwater corrosion resistant with marine-rated seals and bearings

Impellers, O-Rings & Gaskets for QSL Water Pump Systems

To support long-term use and prevent premature failure, it's essential to replace impellers and seals as part of regular engine maintenance.

Marine Water Pump Impeller – Spline Shaft Style

This impeller is engineered with a 14-tooth spline and features a 4-inch width with a 3 3/4” outside diameter. The marine-grade rubber compound resists breakdown from saltwater and heat, ensuring consistent flow rate through the raw water circuit.

Precision spline connection for high torque transfer
Ideal for QSL and QSC seawater pump replacements
Reduced cavitation and improved cooling performance

Mounting Gasket for Cummins Marine Raw Water Pump

Proper installation of your raw water pump requires the right gasket. This marine-rated gasket ensures a tight seal to prevent air or coolant leaks at the pump flange, maintaining system pressure and cooling efficiency.

Designed to handle saltwater exposure
Leak-free performance across varying temperatures
Easy installation with factory-match alignment

Inlet and Outlet O-Rings for Cummins QSL Water Pump

Each QSL marine engine requires two O-rings for proper sealing of inlet and outlet ports on the raw water pump. These high-quality O-rings are formulated to resist swelling and deterioration due to saltwater and coolant exposure.

Durable, long-lasting elastomer formulation
Sold as a pair; two required per engine
Fits QSB4.5, QSB6.7, 6CT8.3, ISC, QSC, and QSL engines

Thermostat & Heat Exchanger Gaskets for Cummins QSL

Thermal regulation is essential to prevent engine overheating and maintain consistent operating temperature in marine applications. Diesel Pro Power stocks all major sealing and temperature control components for Cummins QSL engines.

Thermostat – 180 Degree

This 180° thermostat is designed for marine-duty Cummins QSL, ISL, ISC, and QSC engines. It regulates coolant flow through the engine and heat exchanger, opening and closing based on temperature thresholds to protect against overheating and cold shock.

Precise temperature calibration for optimal engine efficiency
Marine-grade durability against thermal cycling
Reliable opening/closing under load

Heat Exchanger Gasket – Cummins QSL & QSC

Sealing the joint between the heat exchanger and the block or adapter housing, this 5” diameter gasket is built to resist coolant pressure and saltwater corrosion, maintaining a leak-free interface.

Designed for Cummins 6C, 6CT, 6CTA, QSC, L10, and QSL engines
Compatible with OEM heat exchanger configurations
Easy to install with factory-style sealing surfaces

Marine Cooling Accessories: Intake Strainers for QSL Engines

Strainers prevent debris from entering the raw water system, protecting the impeller and internal components of the seawater pump.

Intake Water Strainers – Multiple Sizes Available

Diesel Pro offers marine intake strainers in 1", 1.5", 2", and 2.5" pipe sizes. These strainers are crafted from corrosion-resistant materials and are built for high-flow marine cooling applications. Dimensions range from 9.5” to 16” in heightand 5.5” to 7.5” in width, depending on model.

Protect raw water pump and cooling system from debris
Easy-access screens for maintenance
Rugged marine-grade housing for long life in saltwater environments

Zinc Anodes for QSL Marine Heat Exchangers & Aftercoolers

Zinc anodes help prevent electrolysis and galvanic corrosion inside your cooling system. Diesel Pro's marine zincs fit Cummins QSL heat exchangers and aftercoolers, and feature a standard 1/2” NPT brass plug mount with a 2” zinc element.

Sacrificial protection to extend component life
Easy thread-in installation
Compatible with Cummins and Detroit Diesel marine systems

Cooling System Hoses & Silicone Connectors

Marine environments demand flexible, high-temperature coolant hoses. Our silicone hoses are resistant to UV exposure, saltwater spray, and repeated heating/cooling cycles.

Marine-Grade Silicone Coolant Hoses – 1" to 4" Diameters

Available in 1" to 4" internal diameters, these hoses are sold in 1-foot lengths and can be cut to size. They’re reinforced for pressure resistance and are compatible with seawater, coolant, and antifreeze mixtures.

Ideal for QSL marine cooling systems
Maintains flexibility in extreme temperatures
Built to outlast standard rubber hoses

Hose Clamps for Marine Coolant Lines

Diesel Pro offers a complete range of marine-grade clamps for securing coolant and seawater hoses in QSL engine cooling systems. Each clamp offers a specified effective diameter range to ensure a tight, leak-free connection.

Stainless Steel Clamps – 9/16" to 3" Ranges

Choose from multiple size ranges:

All clamps are corrosion-resistant and designed to withstand vibration and saltwater exposure.

Why Choose Diesel Pro Power for QSL Marine Cooling Parts?

40,000+ satisfied customers worldwide
Fast shipping from in-stock inventory
Expert support for Cummins marine engines
Top-rated quality with marine-specific materials
Trusted for both commercial and recreational marine operations