2003-2005 CUMMINS COOLANT BYPASS KIT

Coolant Bypass Kit | 2003–2005 Dodge/Ram Cummins 5.9L

Stop injector cup failures before they start with the Fleece Performance Coolant Bypass Kit for the 2003–2005 Dodge/Ram 2500/3500 Cummins 5.9L. This kit corrects the factory coolant flow restriction in the cylinder head that allows hot, stagnant coolant to pool around the injector cups — the root cause of one of the most expensive and common failures on the early common rail 5.9L Cummins.

The Problem This Kit Solves

Early common rail 5.9L Cummins engines (2003–2005) are particularly susceptible to injector cup erosion due to inadequate coolant circulation in the head. As coolant stagnates around the cups, localized overheating accelerates corrosion and erosion of the cup sealing surface. Once a cup fails, coolant enters the combustion chamber and fuel system — leading to white smoke, misfires, hydrolocking, and a full head repair bill. The Fleece coolant bypass kit keeps coolant moving continuously, dramatically reducing this risk.

Features

• Corrects factory coolant flow restriction in the cylinder head
• Eliminates hot spots around injector cups
• Dramatically reduces injector cup erosion and failure risk
• Prevents coolant intrusion into the combustion chamber and fuel system
• Complete kit with all hardware needed for installation
• Specifically engineered for the 2003–2005 5.9L Cummins application
• From Fleece Performance — a leader in Cummins reliability and performance

Fitment

• 2003–2005 Dodge Ram 2500/3500 Cummins 5.9L Common Rail

If you own a 2003–2005 5.9L Cummins, this is not an if — it’s a when. Install the Fleece coolant bypass kit now and avoid the most preventable failure on the platform.