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FPE-CLNTBYPS-CUMMINS-MAN Fleece Performance Coolant Bypass Kit - Dodge Cummins 2003-2007 5.9L Manual Transmission

UPC: 635909310419
Manufacturer: Fleece Performance
The Fleece Performance coolant bypass for the 2003-2007 RAM with 5.9L (Manual Transmission) Cummins seamlessly integrates with your truck for an OE fit-and-finish.

PRODUCT DETAILS (click to expand)

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The rear cylinders on the 5.9L Cummins suffer from a lack of coolant flow, and therefore, experience the highest coolant temperatures. This can cause excessive pressure to build in the cooling system, especially the rear of the block and blow out freeze plugs externally, or the smaller diameter plugs under the valve cover, leading to a failure. Our coolant bypass kit adds a secondary thermostat, that unlike other brands, works based on temperature instead of excessive pressure. This solves the problem before pressure becomes an issue by ensuring consistent temperatures across all six cylinders.


  • Lowers coolant temperature at the rear cylinders
  • Ensures consistent temperatures across all cylinders
  • Prevents damaging coolant pressure build up
  • Complete kit comes with braided hose and AN O-ring fittings to ensure a leak-free installation.