Freshwater Pump & Related Components for Cummins Marine & Industrial Engines

When it comes to maintaining ideal engine temperature in Cummins marine and industrial diesel engines, the freshwater pump is only the beginning. The effectiveness of the entire freshwater cooling loop depends on several critical components working together. At Diesel Pro Power, we stock a complete range of high-quality aftermarket parts designed to support and enhance Cummins’ freshwater systems—ensuring consistent engine performance in demanding conditions.

Below is a breakdown of the key components you’ll find in this section of our catalog. These parts are organized by function and compatibility with major Cummins engine series, including the B, C, K, and 855 families.

1. Freshwater Pumps (Circulating Coolant Pumps)

At the heart of any freshwater cooling system is the water pump. These are responsible for circulating coolant through the engine block and cylinder head, regulating heat buildup during operation. Unlike raw water pumps, these are closed-loop pumps designed to work with coolant mixtures and are not exposed to saltwater or debris.

Highlights:

• Designed for long-life in high-heat, high-RPM environments

• Available for Cummins 4BT, 6BT, 6CTA, ISC, QSB, KTA, QSK, NT855, and more

• Offered in both new and remanufactured variants

• Supplied with gaskets or seals where applicable

• Direct bolt-on replacements for most engines

Whether you’re servicing an industrial generator or a marine propulsion system, these pumps are precision-machined for perfect fit and long-lasting performance.

2. Thermostats & Thermostat Assemblies

Thermostats help maintain consistent coolant temperatures and ensure engines warm up quickly to optimal operating conditions. A faulty thermostat can prevent proper coolant flow, leading to overheating or underperformance.

Thermostat Features:

• Exact temperature rating options to match factory specs

• Wax pellet-style for reliable expansion and opening

• Available with housing, gaskets, and bolts in complete kits

• Compatible with electronic control modules on modern engines like QSB or QSC

We stock both standard and high-performance thermostats suitable for tough marine environments and heavy-duty industrial operations.

3. Temperature Gauges, Senders & Switches

Monitoring engine temperature in real time is essential—especially in marine applications where cooling conditions can change rapidly. Diesel Pro Power offers a wide range of compatible monitoring devices for Cummins engines.

Included Components:

• Mechanical and electrical temperature gauges

• Dash panel-ready temperature indicators

• Temperature sensors and senders compatible with Cummins harnesses

• ON/OFF temperature switches to trigger alarms or shutdown systems

• Dual-function sensors for ECM and analog gauge outputs

These units are designed for salt-resistant use, with waterproof connectors and high-vibration tolerance to suit demanding marine or industrial work environments.

4. Fan Belts & Belt Kits

The integrity of the belt drive system is critical to water pump performance. If the belt slips or fails, the pump can no longer circulate coolant efficiently.

Our Belt Inventory Includes:

• V-belts and multi-groove serpentine belts

• Engine-specific belt kits bundled with tensioners and pulleys

• Marine-grade belts with enhanced stretch resistance

• Compatible with front-mounted and side-mounted freshwater pumps

We recommend inspecting belts every 250–500 hours and replacing at the first sign of glazing, cracking, or fraying.

5. Gaskets, O-Rings & Seal Kits

Every connection in a freshwater system is a potential leak point if not properly sealed. Whether replacing a water pump, thermostat, or sensor, Diesel Pro Power has the sealing components to do the job right.

Available Sealing Solutions:

• Water pump gaskets and O-rings (sold separately or included with pump)

• Thermostat housing gaskets

• Mounting flange seals

• Complete coolant-side gasket kits for major engine series

All sealing components are compatible with Cummins-approved coolants and designed to handle elevated temperatures and pressures typical in marine and industrial engines.

6. Engine Paint for Post-Service Protection

After cooling system repairs, applying engine paint isn’t just for aesthetics. In marine environments especially, rust can compromise both performance and resale value.

Key Features of Our Engine Paint Line:

• Heat-resistant and salt-spray tested

• Color-matched to original Cummins engine paint codes

• Quick-dry formulas that bond well to cast iron and aluminum

• Available in aerosol cans for easy field use

Applying a protective coat post-repair helps seal porous castings and protects from ambient corrosion—especially when the engine is regularly exposed to salt air or humidity.

7. Hardware and Mounting Accessories

For customers doing a full cooling system rebuild or replacing a pump for the first time in years, we also offer:

• Mounting bolts, washers, and lock nuts

• Spacer kits for adjusting belt alignment

• Pulley options compatible with Cummins water pumps

• Brackets for remote-mounted freshwater pumps (select models)

These accessories ensure your pump or thermostat installation is not only functional but also reliable under long-term stress.

Trusted Compatibility by Engine Model

Every part in this section is matched by engine model and use case. Whether your Cummins is in a high-speed offshore boat or a backup generator in a remote mining operation, we’ve organized our components by:

• Engine Series (e.g., 6BT, 6CTA, KTA19, QSB, NT855)

• Marine or Industrial Application

• Component Location (front-mounted, rear-mounted, side-mounted configurations)

• Temperature Range Requirements (160°F to 200°F systems)

• Voltage Compatibility (12V and 24V senders or switches)

You can also filter based on your engine serial number, ensuring 100% part compatibility and eliminating guesswork.

Designed for Demanding Environments

Our Fresh Water Pump & Related Component Parts Catalog is engineered for:

• Commercial marine vessels that require durability and fast service intervals

• Industrial engines used in 24/7 mission-critical environments

• Offshore support vessels where heat load is constant

• Auxiliary engines and generator sets in both mobile and stationary installations

Each product in this catalog is built for endurance, vibration resistance, and ease of installation—so you can spend less time in the engine room and more time on the job.

Fresh Water Pump & Related Component Parts Catalog For Cummins 4B, 4BT & 4BTA Engines

Overview

Compact and efficient, the 4B series—including the naturally aspirated 4B, turbocharged 4BT, and aftercooled 4BTA—is widely used in small marine propulsion, gensets, and construction equipment. These 3.9L engines rely on a simple but durable belt-driven freshwater pump to circulate coolant through the engine block.

Catalog Links:

Fresh Water Pump & Related Component Parts Catalog For Cummins 4B 3.9
Fresh Water Pump & Related Component Parts Catalog For Cummins 4BT 3.9
Fresh Water Pump & Related Component Parts Catalog For Cummins 4BTA 3.9

Key Components:

• Freshwater pumps with gaskets

• Compact thermostats (typically 180°F)

• Short V-belts for tight engine bays

• Temp senders for panel integration

Fresh Water Pump & Related Component Parts Catalog For Cummins 6B, 6BT & 6BTA Engines

Overview

The Cummins 5.9L B-series—including the naturally aspirated 6B, turbocharged 6BT, and aftercooled 6BTA—is a workhorse found in marine propulsion systems, auxiliary drives, and generators. These engines rely on belt-driven freshwater pumps and commonly feature compact, serviceable cooling configurations ideal for tight engine compartments.

Catalog Links:

Fresh Water Pump & Related Component Parts Catalog For Cummins 6B 5.9
Fresh Water Pump & Related Component Parts Catalog For Cummins 6BT 5.9
Fresh Water Pump & Related Component Parts Catalog For Cummins 6BTA 5.9

Key Components:

• Direct-fit freshwater pumps with gaskets

• Marine-rated thermostats (180°F or 190°F)

• Reinforced V-belts and serpentine belts

• Temperature senders for marine panels

• Mounting hardware and tensioner kits

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Fresh Water Pump & Related Component Parts Catalog For Cummins ISB & QSB Engines

Overview

ISB and QSB engines (5.9L & 6.7L) represent the evolution of the B-series, adding ECM control and more precise cooling performance. Common in newer marine vessels and industrial repowers.

Catalog Links:

Fresh Water Pump & Related Component Parts Catalog For Cummins ISB 4.5
Fresh Water Pump & Related Component Parts Catalog For Cummins ISB 6.7
Fresh Water Pump & Related Component Parts Catalog For Cummins QSB 4.5

Fresh Water Pump & Related Component Parts Catalog For Cummins QSB 5.9
Fresh Water Pump & Related Component Parts Catalog For Cummins QSB 6.7

Fresh Water Pump & Related Component Parts Catalog For Cummins QSB 7

Key Components:

• ECM-integrated freshwater pumps

• Temperature sensors for digital gauges

• Thermostats with bypass housing options

• Reinforced marine belt kits

Fresh Water Pump & Related Component Parts Catalog For Cummins L10, ISL & QSL Engines

Overview

This medium-duty group balances power and efficiency, often used in larger auxiliary engines and propulsion systems. The L10 is mechanically managed, while ISL and QSL are electronically controlled.

Catalog Links:

Fresh Water Pump & Related Component Parts Catalog For Cummins L10
Fresh Water Pump & Related Component Parts Catalog For Cummins ISL
Fresh Water Pump & Related Component Parts Catalog For Cummins QSL

Key Components:

• Belt- and gear-driven freshwater pumps

• Coolant temperature switches for ECM systems

• Thermostat kits for variable-load duty cycles

• Marine sensor harnesses and belt drives

Fresh Water Pump & Related Component Parts Catalog For Cummins M11, ISM & QSM Engines

Overview

Built for commercial vessels and large industrial equipment, the M11 series and its electronic variants (ISM, QSM) are workhorses that rely on robust closed-loop cooling systems.

Catalog Links:

Fresh Water Pump & Related Component Parts Catalog For Cummins M11
Fresh Water Pump & Related Component Parts Catalog For Cummins ISM
Fresh Water Pump & Related Component Parts Catalog For Cummins QSM11

Key Components:

• High-flow freshwater pumps for marine load

• Dual thermostat configurations (180°F + 190°F)

• ECM-synced temperature sensors

• Heavy-duty fan belts with tensioners

Fresh Water Pump & Related Component Parts Catalog For Cummins NH855, NT855 & N14 Engines

Overview

These inline-six powerplants are found across marine, power generation, and mining fleets. Known for their longevity, their freshwater pumps vary by CPL and cooling configuration (keel-cooled vs. heat exchanger).

Catalog Links:

Fresh Water Pump & Related Component Parts Catalog For Cummins NH 855
Fresh Water Pump & Related Component Parts Catalog For Cummins NT 855
Fresh Water Pump & Related Component Parts Catalog For Cummins N14

Key Components:

• Freshwater pumps (early and updated designs)

• 2-stage thermostat kits

• Analog and 24V sensors for panel monitoring

• Long-life V-belts and full hardware kits

Fresh Water Pump & Related Component Parts Catalog For Cummins ISX & QSX Engines

Overview

High-output and ECM-intensive, the ISX and QSX platforms serve in large boats and land-based systems under constant load. Their cooling systems are fully integrated into ECM logic, requiring high-fidelity sensors and components.

Catalog Links:

Fresh Water Pump & Related Component Parts Catalog For Cummins ISX Single Cam

Fresh Water Pump & Related Component Parts Catalog For Cummins ISX Dual  Cam
Fresh Water Pump & Related Component Parts Catalog For Cummins QSX15

Key Components:

• Marine-grade freshwater pump assemblies

• Dual-loop thermostats

• Multi-sensor wiring options for ECM + gauge

• Belt drives compatible with marine alternators and pumps

Fresh Water Pump & Related Component Parts Catalog For Cummins KTA19, KTA38, KTA50 & QSK19 Engines

Overview

These high-horsepower Cummins engines serve in vessels, mining, power stations, and offshore platforms. Known for their rugged performance, they require robust and efficient freshwater cooling loops.

Catalog Links:

Fresh Water Pump & Related Component Parts Catalog For Cummins KTA 19
Fresh Water Pump & Related Component Parts Catalog For Cummins KTA 38
Fresh Water Pump & Related Component Parts Catalog For Cummins KTA 50
Fresh Water Pump & Related Component Parts Catalog For Cummins QSK 19

Key Components:

• Gear-driven high-output water pumps

• Dual and triple thermostat units for even head cooling

• Marine-rated sensor kits with backup alarms

• Heavy-duty pulley and mounting systems

Frequently Asked Questions (FAQs) About Freshwater Pumps For Cummins Engines

General Freshwater Pump Questions

1. What does a freshwater pump do in a Cummins engine?
A freshwater pump circulates coolant through the engine block and cylinder head to regulate internal temperature and prevent overheating during operation.

2. How is a freshwater pump different from a raw water pump?
A freshwater pump is part of a closed-loop cooling system using coolant or antifreeze. A raw water pump draws seawater or lake water through a heat exchanger. Each has a dedicated section in our catalog.

3. How often should a freshwater pump be replaced?
Every 3–5 years or after approximately 4,000–6,000 engine hours, depending on usage, load, and environmental conditions.

4. What are signs my freshwater pump is failing?
Look for engine overheating, coolant leaks, belt squealing, low coolant flow, or visible rust or corrosion on the pump housing.

5. Do you sell new or rebuilt freshwater pumps?
We only sell brand-new freshwater pumps for Cummins engines. Our aftermarket pumps are built to OEM-equivalent specifications or better.

Compatibility & Engine Matching

6. How do I know which freshwater pump fits my Cummins engine?
Search by engine model, CPL number, or serial number on our website. If you need assistance, contact our support team for help confirming compatibility.

7. Do you need the CPL number to find the correct freshwater pump?
A CPL (Control Parts List) number is helpful for models like 6CTA, QSB, and KTA series. If not available, provide the full engine serial number instead.

8. Are these parts compatible with both marine and industrial Cummins engines?
Yes. Our freshwater pumps are designed for both marine and industrial applications and are matched specifically by engine model and use case.

9. Do you sell freshwater pump kits organized by engine model?
Yes. Each engine family (e.g., 6BT, QSM, NT855) has its own catalog page where pumps, gaskets, thermostats, belts, and sensors are bundled or listed together.

10. Are freshwater pumps the same across all Cummins engine models?

No. Freshwater pumps vary by engine series, horsepower rating, mounting configuration, drive type (belt or gear), and cooling system design. That’s why we organize our catalog by engine model, so you get the exact match for your Cummins engine.

Installation & Maintenance

11. How do I install a new freshwater pump on my Cummins engine?
For proper installation, refer to the Cummins OEM service manual specific to your engine model. The manual includes torque specs, sequence, and any special procedures required. Always clean mounting surfaces and replace gaskets during installation.

12. Is the gasket or O-ring included with the freshwater pump?
Yes. Most of our freshwater pumps include the required gasket or O-ring. Each product page clearly lists included items. If not, we offer separate gasket kits.

13. Should I replace the thermostat when replacing the freshwater pump?
Yes, it's highly recommended. A thermostat failure can lead to overheating or improper coolant flow, even with a new pump. Replacing both ensures full system reliability.

14. How do I know if my temperature gauge or sensor is working properly?
You can verify temperature gauge accuracy by comparing it to an infrared thermometer reading at the thermostat housing. To test the sensor, use a multimeter and compare resistance to Cummins specs.

15. What kind of belt do I need for my Cummins freshwater pump?
It depends on your engine model and pump configuration. We offer marine-grade V-belts and serpentine belts organized by engine type, and our team can confirm compatibility using your engine's serial number.

Product Support & Specifications

16. Are your freshwater pumps OEM or aftermarket?
We sell high-quality aftermarket freshwater pumps for Cummins engines. Each unit is manufactured to meet or exceed OEM specifications, providing the same fit, function, and long-term performance you expect.

17. What materials are used in your freshwater pumps?
The materials used in our freshwater pumps are based on the original OEM specifications unless improved for aftermarket durability. Most pumps are built with cast iron or aluminum housings, and all include corrosion-resistant impellers, durable seals, and long-lasting bearings suitable for marine and industrial use.

18. Do your temperature sensors work with digital and analog gauges?
Yes. We offer temperature sensors and senders compatible with both analog gauge panels and digital or ECM-controlled displays, depending on your Cummins engine configuration.

19. Can I buy a full freshwater cooling system rebuild kit?
Yes. We offer complete rebuild kits by engine model. These may include the freshwater pump, thermostats, gaskets, temperature sensors, fan belts, and mounting hardware—all matched to your Cummins engine.

20. Do you offer mounting kits, belts, or pulleys with freshwater pumps?
Yes. We stock complete kits for many Cummins engines that include freshwater pumps, belts, pulleys, brackets, and hardware for a full and secure installation. Product pages specify compatible accessories for each engine.

Shipping, Ordering & Warranty

21. How quickly will my freshwater pump ship after ordering?
Orders placed during business hours typically ship within 24 hours. We offer expedited and international shipping options for customers worldwide.

22. Do you offer international shipping for Cummins engine parts?
Yes. Diesel Pro Power ships Cummins freshwater pumps and components to over 180 countries, offering fast and reliable service with full tracking and support.

23. What type of warranty do you provide on freshwater pumps?
All new freshwater pumps sold by Diesel Pro Power come with a 1-year warranty against defects in materials and workmanship. This warranty applies to normal use in marine and industrial applications and reflects our commitment to providing dependable aftermarket parts.

24. What if I accidentally order the wrong pump?
If you order the incorrect freshwater pump, contact our support team right away. We’ll help you confirm the correct part and arrange a return or exchange, as long as the pump has not been installed and is in its original condition.

25. Can I talk to someone directly before placing my order?
Yes. Our team is available to help you by phone or online. Call 1-888-433-4735 (U.S.) or 305-545-5588 (International), or use the live chat feature on our website to speak with a Diesel Pro Power expert.