SKU: 56458609582

Fleece Performance FPE-CLNTBYPS-CUMMINS-MAN Cummins Coolant Bypass Kit 2003-2007 Manual Transmission Fleece Performance

Sale price$245.70 Regular price$273.00
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Description

Fleece Performance FPE-CLNTBYPS-CUMMINS-MAN Cummins Coolant Bypass Kit 2003-2007 Manual Transmission Fleece PerformanceIncreased 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

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 and up 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.

The 03-07 5.9L automatic transmission version will eliminate the factory transmission fluid heat exchanger. The heat exchanger is not a fluid cooler; it was designed for use in cold climates to warm the transmission fluid with the engine coolant.

It is not necessary for use in warm climates or high horsepower applications, nor does it detrimentally affect the trucks performance when removed. All 07-13 6.7 trucks, both automatic and manual equipped transmissions, do not have a transmission fluid heat exchanger.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
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  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 56458609582

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peter
Houston, US
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Great socks
Fit Type: Classic Fit, Color: Black, Size: Large
Love these socks, very comfortable and look and feel good quality
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Reviewed in the United States on June 29, 2025
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PPeter
Charlottesville, US
★★★★★ 1
Too large. Correct size not depicted.
SIZE 10-14... Too large. Product details says "Regular" size. Returning.
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Reviewed in the United States on March 16, 2026
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Stacey Lovejoy
Pawtucket, US
★★★★★ 2
Too big
The one size fits all was too big for me.
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Glass
Chelsea, US
★★★★★ 5
I stay on your foot they don’t slip in your shoe
Number of Items: 3, Color: White/Neutral (3-pairs), Size: Medium
This is the only socks I wear Under Armour because they stay in place I wear a size 8, but they’re more comfortable with a large instead of a medium, but I wear both because I have them already and you can pull them to stretch them out a little bit
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Reviewed in the United States on May 12, 2026

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