California Residents: Prop 65 WarningDescription
Fleece Performance Coolant Bypass Kit (Black)
Fitment
94-98 5.9L Dodge Cummins 12V Auto Trans
Increased Coolant Flow, Decreased Coolant Temperatures
The rear cylinders on the 5.9/6.7L 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 the pressure becomes an issue by ensuring consistent temperatures across all six cylinders.
Benefits:
- Lowers coolant temperature at the rear cylinders
- Ensures consistent temperatures across all cylinders
- Prevents damaging coolant pressure build-up
- Complete kit comes with a braided hose and AN O-ring fittings to ensure a leak-free installation. Kits for MY 2003+ include billet hose brackets.
Why do I need a Fleece Coolant Bypass?
One of the biggest issues on the 5.9/6.7L Cummins is the coolant flow problem to the rear cylinders. This can cause catastrophic failure or blowouts 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.
Application Notes:
The 2003 – 2007 5.9L automatic transmission version will eliminate the factory transmission fluid heat exchanger. The heat exchanger is designed for use in cold climates to warm the transmission fluid with the engine coolant. It is not necessary for use in warm climates or high horsepower applications, nor does it detrimentally affect the truck’s performance when removed.
For model years 2007 – 2018 6.7L trucks, including both automatic and manual-equipped transmissions, factory-installed transmission fluid heat exchangers are uncommon. For customers with a 6.7L that has a heat exchanger, a heater tube can be purchased at your local Chrysler Dealership [PN:68048997AA] to complete the installation.
Cummins Coolant Bypass Kit. Another product from Fleece Performance built out of necessity is the 2003-2016 Cummins Coolant Bypass kit. The Cummins engine cooling system was designed to adequately cool a 300-350hp engine.
When the horsepower is increased there is an increased demand for the cooling system. The rear cylinders suffer from a lack of coolant flow, and therefore, experience the highest coolant temperatures. This can cause excessive pressure to build in the system, especially the rear of the block, and possibly blow out freeze plugs externally, or the smaller diameter plugs under the valve cover, leading to a failure.
We’ve designed our coolant bypass kit with a secondary thermostat, that unlike other brands, works based on temperature instead of excessive pressure. This solves the problem before the pressure becomes an issue by ensuring consistent temperatures across all six cylinders. Our kit comes with high quality AN o-ring fittings and AN hose connections with braided hose to ensure a leak-free installation.
