Skip to product information
1 of 1

Fleece Performance Engineering

Fleece Coolant Bypass Kit for 2007.5-2012 RAM with 6.7L Cummins

Fleece Coolant Bypass Kit for 2007.5-2012 RAM with 6.7L Cummins


Regular price $559.99
Regular price Sale price $559.99
Sale Sold out
Shipping calculated at checkout.


In Stock ships same or next business day

The Fleece Performance coolant bypass for the 2007.5-2012 RAM with 6.7L Cummins seamlessly integrates with your truck for an OE fit-and-finish. 



Increased Coolant Flow, Decreased Coolant Temperatures

The rear cylinders on the 6.7L 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.


Why do I need a Fleece Coolant Bypass?

One of the biggest issues on the 6.7L Cummins is the coolant flow problem to the rear cylinders. This can cause catastrophic failure or blow outs of the freeze plugs in an over-temperature / over-pressure condition.  The Fleece Coolant Bypass is one of the most important additions you make to improve the reliability and longevity of the Cummins platform. 


Kit Includes:

  • Rear coolant bypass thermostat housing
  • Front coolant bypass thermostat housing
  • New EGR cross-over tube gaskets
  • Braided nylon coolant bypass hose with protective high temperature sleeve and AN fittings
  • Exhaust back pressure sensor mounting block and back pressure sensor line
  • Mounting hardware


Without Coolant Bypass    

* Patent Pending



For model years 2007 - 2018 6.7L trucks, including both automatic and manual equipped transmissions, factory installed transmission fluid heat exchangers are uncommon but can be found in northern climates. For customers with a 6.7L that has a factory installed heat exchanger, an additional heater tube is required and can be purchased at your local Chrysler Dealership [PN:68048997AA] to complete the installation.


View full details