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 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 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
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.
Instructions