2007-2018 6.7L Dodge Ram Diesel Engines Coolant Bypass Kit

2003-2018 5.9L 6.7L RAM Coolant Bypass Kit

Improve the performance of your motor!

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How it Installation?

Installation instructions

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Step 1 :

Disconnect the vehicle battery and locate a 58mm (2 ¼ inch) large freeze plug at the rear of the engine block. Use a rod and hammer to push the outer edge of the freeze plug from under the truck, remove the freeze plug from the cylinder block, and clean the surface area of the cylinder block from the cylinder head to the rear cover, as well as the hole where the freeze plug was previously installed.

Step 2 :

Screw the end of the coolant bypass hose with a direct head onto the coolant bypass thermostat housing, thoroughly lubricate the sealing ring O-ring on the coolant bypass thermostat housing with assembly grease or light oil, and then press the position at the rear of the engine cylinder. Slide the thermostat housing between the firewall and the rear of the engine block.

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Step 3 :

Remove the oil dipstick Remove the engine hood. Disconnect the EGR temperature sensor connector and fixing clip. No need to remove the sensor from the horizontal pipe. Remove the EGR crossover pipe and remove the heat shield.

Step 4 :

Remove the two 8mm bolts that secure the heat shield to the top of the cooler elbow. Remove the heat shield. Fix the O-ring onto the radiator and re secure the radiator ventilation pipe with the screws provided in the kit.

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Step 5 :

1.Connect the coolant bypass hose at one end of the thermostat housing to the ventilation pipe.
2.Secure the coolant bypass hose with the buckle of the kit.

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

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

$86.59

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.

Key Features

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.

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