Fleece Performance 98.5-02 VP Coolant Bypass Kit with Stainless Steel Braided Line for Cummins 5.9/6.7L Engines

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.

• 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 98.5-02 VP Coolant Bypass Kit is an essential upgrade for Cummins 5.9 and 6.7-liter engines, designed to improve coolant flow and temperature management. The rear cylinders on these engines are prone to inadequate coolant circulation, leading to elevated temperatures that can cause excessive pressure buildup and potential failure of freeze plugs. This kit introduces a secondary thermostat that operates based on temperature, ensuring consistent cooling across all cylinders and preventing overheating issues before they escalate.
Constructed with high-quality stainless steel braided hose and AN O-ring fittings, the kit guarantees a leak-free installation and durability under demanding conditions. For model years 2003 and newer, billet hose brackets are included to facilitate a secure and professional fit. Proper coolant flow is crucial for engine longevity, especially in severe operating environments where overheating can lead to catastrophic engine failure. The Fleece coolant bypass enhances reliability by maintaining uniform temperature distribution, thereby reducing stress on the cooling system components and extending the lifespan of your engine.
The kit also serves a specific function for vehicles equipped with automatic transmissions from 2003 to 2007, as it replaces the factory transmission fluid heat exchanger designed for cold climate operation. This modification helps prevent heat transfer issues that can occur in warmer environments, ensuring efficient transmission cooling and optimal performance. Installation of this bypass kit is straightforward, and it offers a significant benefit in preventing coolant pressure buildup that could otherwise damage engine components. Overall, the Fleece Performance coolant bypass kit is a vital upgrade for anyone looking to enhance the durability and performance of their Cummins engine, especially in demanding driving conditions or heavy-duty applications.

Features:

• Increases coolant flow to rear cylinders, reducing high-temperature zones

• Operates based on temperature to prevent pressure buildup and damage

• Includes braided stainless steel hose and AN O-ring fittings for leak-proof installation

• Supplies billet hose brackets for model years 2003 and newer

• Maintains consistent cylinder temperatures for improved engine longevity

• Prevents freeze plug blowouts caused by overheating and excessive pressure

• Designed to enhance reliability and reduce cooling system stress

• Replaces factory transmission fluid heat exchanger on select models

Air Freight Prohibited: false
Not Carb Approved: true
Ltl Freight Required: false
Prop 65: Y
Part Type: automotive
Epa: N/A
Carb Acknowledgement Required: false
Regular Stock: t
Units Per Sku: 1