TruckTok 2003-2007 5.9L & 2007.5-2018 6.7L Dodge Ram Cummins Diesel Engines Coolant Bypass Kit

FITMENT

• 2003-2007 Dodge Ram Cummins 5.9L (Only Manual Transmission!).
• 2007.5-2018 Dodge Ram Cummins 6.7L (Manual & Automatic Transmissions.).

DESCRIPTION

Product Overview

• The 2003–2018 Ram Cummins blocks (both the 5.9L and 6.7L) are legendary for their raw power and longevity. However, they suffer from a critical factory engineering flaw: poor coolant flow at the back of the engine.
  
• The factory water jacket prioritizes the front cylinders, causing coolant to stall and boil around cylinder number 6. This localized overheating builds immense pressure and extreme temperature spikes, leading to blown head gaskets, cracked blocks, and dropped valve seats.
• This kit is a vital necessity for manual transmission trucks to establish a secondary cooling circuit, venting trapped pressure and keeping rear cylinder temperatures perfectly balanced.

• Premium Braided Lines & CNC Fittings: Features ultra-durable braided hoses paired with CNC-machined aluminum fittings for a leak-free seal that handles extreme high-pressure spikes.
  
• Prevents Blown Head Gaskets: Creates a dedicated flow path from the rear of the block directly to the thermostat housing, eliminating deadly coolant stagnation at cylinder number 6.
• Lowers Operating Temperatures: Drops engine temperatures uniformly, ensuring your cooling system works efficiently even when dragging heavy loads up steep grades.
• Thermostatic Flow Control: Features a high-quality inline thermostat that only opens when the rear block demands extra flow, preventing engine over-cooling during winter.

FAQ

Q: Will this kit fit my automatic transmission truck?

A: It depends on your year. For 03–07 5.9L models, this kit fits Manual Transmissions Only due to tight clearance around early automatic bellhousings. For 07.5–18 6.7L models, it is fully compatible with both Manual and Automatic Transmissions.

Q: Why does my Cummins engine need an external bypass line?

A: The factory cooling system pumps coolant from front to back, causing the flow to stall and overheat by the time it reaches cylinder number 6. This bypass kit eliminates that bottleneck to create a continuous, safe cooling loop.

Q: Can I run this bypass kit during the winter without losing my cab heater?

A: Unlike cheap, unregulated bypass hoses that stay wide open, our kit features a built-in thermostat that remains closed until the engine warms up, ensuring your cab heater works fast in freezing temperatures.

Q: Do I need an aftermarket tuner or computer flash after installing this?

A: No. This is a mechanical cooling upgrade. It does not touch emissions sensors or alter factory electronics, so it will never throw a dashboard fault code or engine light.