{"product_id":"fleece-coolant-bypass-kit-fpe-clntbyps-cummins-man-2003-2007-5-9l-cummins-manual-transmission","title":"FLEECE COOLANT BYPASS KIT FPE-CLNTBYPS-CUMMINS-MAN | 2003-2007 5.9L CUMMINS (MANUAL TRANSMISSION)","description":"\u003cp\u003eImprove coolant circulation and maintain more consistent cylinder temperatures in your 2003–2007 Dodge\/Ram 5.9L Cummins with manual transmission using the Fleece Performance FPE-CLNTBYPS-CUMMINS-MAN Coolant Bypass Kit. Designed to address reduced coolant flow through the rear of the engine, this system helps lower rear-cylinder temperatures and reduce excessive cooling-system pressure.\u003c\/p\u003e\n\u003cp\u003eUnder demanding operating conditions, the rear cylinders of the 5.9L Cummins can experience higher coolant temperatures due to reduced coolant flow. As temperatures increase, pressure can build at the rear of the engine and increase the risk of freeze plug failure.\u003c\/p\u003e\n\u003cp\u003eThe Fleece Coolant Bypass Kit incorporates a \u003cstrong\u003etemperature-activated secondary thermostat\u003c\/strong\u003e that provides additional coolant flow when needed. By regulating the bypass based on coolant temperature rather than excessive pressure, the system helps maintain more consistent temperatures across all six cylinders.\u003c\/p\u003e\n\u003cp\u003eThe kit uses high-quality O-ring fittings and AN-style hose connections for a secure installation and is available with either \u003cstrong\u003ebraided black nylon or braided stainless steel hose\u003c\/strong\u003e. Installation does not require removal of the cylinder head.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eImproved rear-cylinder coolant flow\u003c\/strong\u003e – Helps maintain more consistent coolant temperatures throughout the engine\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature-activated secondary thermostat\u003c\/strong\u003e – Provides additional coolant flow based on temperature\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReduces pressure buildup\u003c\/strong\u003e – Helps prevent excessive cooling-system pressure at the rear of the engine\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMore consistent cylinder temperatures\u003c\/strong\u003e – Helps equalize coolant temperatures across all six cylinders\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo cylinder head removal required\u003c\/strong\u003e – Designed for installation without removing the cylinder head\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eO-ring fittings and AN connections\u003c\/strong\u003e – Provides secure, leak-resistant coolant connections\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTwo hose options\u003c\/strong\u003e – Available with braided black nylon or braided stainless steel hose\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1-year limited warranty\u003c\/strong\u003e – Covered according to current Fleece Performance warranty terms\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eApplication Notes\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eFor manual transmission-equipped trucks only.\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003eDesigned to improve coolant circulation through the rear cylinders of the 5.9L Cummins.\u003c\/li\u003e\n\u003cli\u003eVerify all fittings, hoses, and sealing surfaces during installation to ensure proper cooling-system operation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eFitment:\u003c\/strong\u003e 2003–2007 Dodge\/Ram 5.9L Cummins with Manual Transmission\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e FPE-CLNTBYPS-CUMMINS-MAN\u003c\/p\u003e","brand":"Fleece Performance Engineering","offers":[{"title":"Default Title","offer_id":54105312657691,"sku":"FPE-CLNTBYPS-CUMMINS-MAN","price":379.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0962\/5757\/3147\/files\/Screenshot2026-10-05at11.33.38AM.png?v=1791221649","url":"https:\/\/wwmperformance.com\/products\/fleece-coolant-bypass-kit-fpe-clntbyps-cummins-man-2003-2007-5-9l-cummins-manual-transmission","provider":"WWM Performance","version":"1.0","type":"link"}