Cummins QSC Engine Water Pump - Aftermarket

Cummins QSC Freshwater Pump & Cooling System Parts Catalog

Keep your Cummins QSC engine running at optimal temperature with Diesel Pro Power’s complete catalog of aftermarket freshwater pump and cooling system components. Designed specifically for the QSC's demanding marine and industrial environments, these components are built to maintain reliability, reduce downtime, and extend the life of your engine.

Whether you're performing routine maintenance or replacing a failed water pump, our catalog includes all essential parts—starting with two aftermarket pump options tailored for the Cummins QSC platform.

Aftermarket Freshwater Pumps for Cummins QSC

The Cummins QSC uses a freshwater cooling loop that circulates coolant through the engine block, cylinder head, oil cooler, and heat exchanger. Diesel Pro Power offers two compatible aftermarket water pump options, both tested in real-world QSC applications and backed by our reputation for quality.

Primary Aftermarket Water Pump for Cummins QSC

This is the most common direct-fit replacement water pump used in the Cummins QSC. Designed to match OEM specifications, this pump is compatible with dozens of QSC CPL configurations.

Supported CPL Numbers for QSC Engines:

2964, 8641, 1754, 3301, 8647, 1404, 1096, 8221, 8389, 8458, 8220, 8627, 8630, 3212, 2, 2693, 2694, 2695, 2691, 2237, 2946, 2475, 422, 8695, 8693, 8648, 401, 8650, 400, 8478, 8538, 8639, 8636, 8537, 8153, 8152, 8151, 8780, 8697, 8730, 8692, 8159, 8056, 1632, 2722, 8746, 1738, 1793, 1286, 8703, 8185, 2997, 8307, 2996

Key Features:

• Aftermarket replacement designed specifically for Cummins QSC engines

• Cast iron construction with a marine-grade finish

• Heavy-duty bearings and shaft seals for high-humidity environments

• Drop-in fit—no modifications required

• Ideal for standard maintenance or full cooling system overhaul

Alternate Water Pump Option for Custom QSC Applications

For some Cummins QSC configurations—especially custom or repowered setups—this second water pump offers reliable coolant flow and bolt-on compatibility. While it originates from other Cummins platforms, it has been successfully adapted in QSC marine systems where certain heat exchanger layouts or bracket orientations require a modified pump profile.

Use Case:

• Commonly used in custom QSC repower projects

• Works with non-standard QSC cooling setups

• Precision aftermarket build with reliable marine performance

• Built from corrosion-resistant metals with high-flow impeller

Note: Please confirm your existing pump housing and mounting bracket dimensions to ensure proper fit.

Thermostat for Cummins QSC

Maintaining the correct operating temperature is critical to QSC engine longevity. This 180°F thermostat is a direct replacement engineered specifically for the QSC cooling loop.

Features:

• Opens at 180°F (82°C) to allow coolant circulation

• OEM-style brass and stainless-steel construction

• Drop-in design for quick installation

• Helps regulate EGTs and reduce wear from cold starts

Serpentine Belts for Cummins QSC Water Pump Drive

Your Cummins QSC engine uses a serpentine belt system to drive the freshwater pump, alternator, and other front-mounted accessories. We carry multiple 8-rib belts sized to match various QSC engine pulley setups.

Available Belt Sizes (All 8-rib, 1.125” wide):

• 53.5"

• 57.5"

• 59.5"

• 60.0"

• 66.53"

• 66.92"

• 69.0"

Belt Benefits:

• Designed for continuous-duty marine operation

• Oil- and heat-resistant compound

• Reinforced internal structure for high torque loads

• Smooth, quiet operation in saltwater conditions

Idler Pulley for Cummins QSC Cooling System

Our grooved idler pulley for the Cummins QSC helps maintain belt tension and alignment for optimal water pump operation. It's built with heavy-duty bearings to endure high-RPM marine duty cycles.

Pulley Specifications:

• Grooved to match 8-rib serpentine belts

• Precision-balanced for vibration control

• Sealed bearing design for marine environments

• Prevents belt slipping and premature wear

Silicone Coolant Hoses for Cummins QSC

Upgrade or replace your coolant hoses with marine-rated silicone hoses—offering superior flexibility, heat resistance, and durability over rubber alternatives. These are available by the foot in a wide range of diameters to accommodate all coolant line sizes on the QSC.

Available Inside Diameters (All 1-foot lengths):

• ¾", 1", 1¾", 1⅞", 2", 2⅛", 2¼", 2⅜", 2½", 2¾", 3", 3½", 4"

Advantages:

• Multi-layer silicone reinforcement for high-pressure operation

• Withstands high-temperature engine bays

• Saltwater and antifreeze resistant

• Flexible and easy to route in tight compartments

Stainless-Steel Hose Clamps for QSC Cooling Hoses

Secure your coolant lines with marine-grade stainless steel clamps designed to withstand heat, salt, and constant vibration. Available in multiple sizes to match your silicone hose selection.

Effective Diameter Ranges:

• From 9/16” to 3½”

• Corrosion-resistant stainless steel

• Worm-drive mechanism for even pressure

• Reusable and easy to adjust in tight spaces

Other Cooling System Accessories for QSC Engines

Radiator Cleaner

• Cleans internal freshwater circuits in QSC heat exchanger systems

• Non-toxic, safe for aluminum and copper components

Temperature Switch (205°F)

• Compatible with alarm or fan circuits

• Activates at 205°F

• Thread size: ½” NPT

Gauges

• Mechanical and electric temperature gauges

• Available in 12V and 24V options

• Designed for marine engine panels

Why Choose Diesel Pro Power for Cummins QSC Cooling Parts?

• ✔ 40,000+ satisfied customers worldwide

• ✔ In-stock freshwater pumps and cooling parts

• ✔ Global shipping with fast order turnaround

• ✔ All parts vetted for marine-duty use

• ✔ Expert support for Cummins QSC maintenance and repowers