Fleece Performance 03-05 Auto Trans Cummins Coolant Bypass Kit with Stainless Steel Braided Line

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. 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. Cummins Coolant Bypass Kit (2003-2005 Auto Trans) w/ Stainless Steel Braided Line

• Complete kit comes with braided hose and AN O-ring fittings to ensure a leak-free installation
• Ensures consistent temperatures across all cylinders
• Lowers coolant temperature at the rear cylinders
• Prevents damaging coolant pressure build up

The Fleece Performance coolant bypass kit is an essential upgrade for 2003-2005 model year Cummins 5.9L and 6.7L engines with automatic transmissions. Designed to address the common issue of inadequate coolant flow to the rear cylinders, this kit helps maintain optimal operating temperatures and prevent potential engine failures. The kit includes a secondary thermostat that operates based on temperature, ensuring consistent coolant temperatures across all cylinders rather than relying solely on pressure, which can lead to dangerous pressure build-up. This proactive approach helps reduce coolant temperatures at the rear cylinders, preventing blowouts of freeze plugs and extending engine longevity. Constructed with durable stainless steel braided hose and high-quality AN O-ring fittings, the installation is designed to be leak-free and reliable. Additionally, models for MY 2003+ include billet hose brackets for a secure fit. Implementing this coolant bypass significantly enhances engine reliability by promoting even coolant distribution, reducing the risk of catastrophic failures, and supporting longer engine life. Notably, for 2003-2005 automatic transmissions, this kit also eliminates the factory transmission fluid heat exchanger, which is primarily designed for cold climates to warm the transmission fluid. This makes the kit particularly suitable for various operating environments, providing peace of mind and improved cooling performance. The complete assembly is compliant with EPA standards and features a CARB acknowledgment, making it a compliant upgrade for many applications. Overall, the Fleece Performance coolant bypass kit is a vital addition for maintaining the health of your Cummins engine, ensuring consistent performance, and preventing costly repairs caused by uneven coolant flow and overheating issues.

Features:

• Complete kit includes braided hose and AN O-ring fittings for a leak-free installation

• Secondary thermostat operates based on temperature to ensure consistent cylinder cooling

• Reduces coolant temperature at the rear cylinders, preventing overheating

• Eliminates damaging coolant pressure build-up, increasing engine reliability

• Includes billet hose brackets for MY 2003+ models for a secure fit

Air Freight Prohibited: false
Not Carb Approved: false
Ltl Freight Required: false
Prop 65: Y
Part Type: automotive
Epa: Compliant
Carb Acknowledgement Required: false
Carb Eo Number: D-834-9
Regular Stock: t
Units Per Sku: 1