Coolant Bypass for 2006-2007 Automatic Transmission Fleece Performance

Keep the rear cylinders cool

On the 5.9L Cummins, the cylinders at the back of the block are short on coolant flow and run the hottest. The extra heat can build pressure at the rear of the block and push out freeze plugs, including the small ones under the valve cover.

The Fleece Coolant Bypass adds a second thermostat that works on temperature, not pressure, so all six cylinders stay at an even temperature before pressure ever becomes a problem.

The kit comes with braided hose, AN O-ring fittings for a leak-free install and billet hose brackets.

Who it's for

Owners of 2006-2007 Dodge Ram 2500/3500 5.9L Cummins trucks with an automatic transmission.

Key specs (per Fleece)

What's included

• Coolant Bypass thermostat assembly
• Braided hose with AN O-ring fittings
• Billet hose brackets

Fitment notes

• Fits 2006-2007 Dodge Ram 2500/3500 with the 5.9L Cummins and automatic transmission (per Fleece).
• This version removes the factory transmission fluid heat exchanger, which warms the fluid with engine coolant in cold climates. Fleece says it is not needed in warm climates or high-power builds and does not hurt performance when removed.
• California: Fleece lists CARB EO D-834-9 for this part.

Professional install available at Powertech Diesel, Idaho Falls — call 208-542-7793.