Fleece Coolant Bypass Kit (Auto Trans) for 2003-2005 Dodge Ram 5.9L Cummins

Freeze plugs blowing out on the back of your 2003-2005 Cummins automatic? Hot rear cylinders are usually the reason.

The rear cylinders on the 5.9/6.7L Cummins don't see enough coolant flow, so they run hottest and build pressure in the back of the block. Fleece's bypass adds a secondary thermostat that works on temperature, not excessive pressure, and keeps temps consistent across all six cylinders before pressure ever becomes an issue. Fleece calls it one of the most important reliability additions for the Cummins platform.

Benefits

• Lowers coolant temperature at the rear cylinders
• Ensures consistent temperatures across all six cylinders
• Prevents damaging coolant pressure build up
• Secondary thermostat that works on temperature, not excessive pressure
• Braided hose and AN O-ring fittings for a leak-free install
• Billet hose brackets included on kits for MY 2003+

Note: The '03-'07 5.9L automatic transmission version will eliminate the factory transmission fluid heat exchanger. The heat exchanger is not a fluid cooler; it was 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. All 07-13 6.7 trucks, both automatic and manual equipped transmissions, do not have a transmission fluid heat exchanger.

Specs

• Transmission: Automatic (2003-2005)
• Engine: 5.9L Cummins
• Part number: FPE-CLNTBYPS-CUMMINS-0305
• CARB EO: D-834-9

Why we run it

Even coolant temps front to back, and no pressure spikes waiting to pop a freeze plug. That's what this bypass gives a 2003-2005 automatic 5.9L. Fleece's thermostat works on temperature instead of excess pressure, so it fixes the problem before it becomes one, and billet hose brackets keep the install tidy. PPEI recommends a Fleece bypass on Cummins trucks that tow, and it's a part we use on our own trucks.

Fitment

• Dodge Ram 2500: 2003,2005 Laramie; 2003-2005 SLT, ST
• Dodge Ram 3500: 2003-2005 Laramie, SLT, ST