{"product_id":"4067677c2-genuine-international®-def-return-tube","title":"4067677C2 | Genuine International® DEF Return Tube","description":"\u003cp\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e DEF Return Tube\u003cbr\u003e\u003cstrong\u003eCondition: \u003c\/strong\u003eNew \u003cbr\u003e\u003cstrong\u003eBrand: \u003c\/strong\u003eInternational\u003cstrong\u003e®\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e 4067677C2\u003c\/p\u003e\n\u003cdiv class=\"\"\u003e\n\u003csection class=\"text-token-text-primary w-full focus:outline-none has-data-writing-block:pointer-events-none [\u0026amp;:has([data-writing-block])\u0026gt;*]:pointer-events-auto R6Vx5W_threadScrollVars scroll-mb-[calc(var(--scroll-root-safe-area-inset-bottom,0px)+var(--thread-response-height))] scroll-mt-(--header-height)\" dir=\"auto\"\u003e\u003c\/section\u003e\n\u003cstrong\u003eFitment Guide: \u003c\/strong\u003eInternational\u003cbr\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"\"\u003e\n\u003csection class=\"text-token-text-primary w-full focus:outline-none has-data-writing-block:pointer-events-none [\u0026amp;:has([data-writing-block])\u0026gt;*]:pointer-events-auto R6Vx5W_threadScrollVars scroll-mb-[calc(var(--scroll-root-safe-area-inset-bottom,0px)+var(--thread-response-height))] scroll-mt-[calc(var(--header-height)+min(200px,max(70px,20svh)))]\" dir=\"auto\"\u003e\n\u003cdiv class=\"text-base my-auto mx-auto pb-3 [--thread-content-margin:var(--thread-content-margin-xs,calc(var(--spacing)*4))] @w-sm\/main:[--thread-content-margin:var(--thread-content-margin-sm,calc(var(--spacing)*6))] @w-lg\/main:[--thread-content-margin:var(--thread-content-margin-lg,calc(var(--spacing)*16))] px-(--thread-content-margin)\"\u003e\n\u003cdiv class=\"[--thread-content-max-width:40rem] @w-lg\/main:[--thread-content-max-width:48rem] mx-auto max-w-(--thread-content-max-width) flex-1 group\/turn-messages focus-visible:outline-hidden relative flex w-full min-w-0 flex-col agent-turn\"\u003e\n\u003cdiv class=\"flex max-w-full flex-col gap-4 grow\"\u003e\n\u003cdiv dir=\"auto\" class=\"min-h-8 text-message relative flex w-full flex-col items-end gap-2 text-start break-words whitespace-normal outline-none keyboard-focused:focus-ring [.text-message+\u0026amp;]:mt-1\" tabindex=\"0\"\u003e\n\u003cdiv class=\"flex w-full flex-col gap-1 empty:hidden\"\u003e\n\u003cdiv class=\"markdown prose dark:prose-invert wrap-break-word w-full light markdown-new-styling\"\u003e\n\u003cp\u003e\u003cbr\u003eA DEF Return Tube is part of a diesel engine’s SCR (Selective Catalytic Reduction) system. It is a small line that returns unused or excess Diesel Exhaust Fluid (DEF) back to the DEF tank or dosing system.\u003c\/p\u003e\n\u003cstrong\u003e\u003c\/strong\u003e\n\u003ctable width=\"100%\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e \n\u003cp\u003e\u003cstrong\u003e1. Returns unused DEF\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eNot all DEF sent to the injector is used.\u003c\/li\u003e\n\u003cli\u003eThe return tube carries the extra DEF back instead of wasting it.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e2. Maintains correct system pressure\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eHelps regulate pressure in the DEF dosing circuit.\u003c\/li\u003e\n\u003cli\u003ePrevents pressure buildup that could damage components.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e3. Improves dosing accuracy\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eKeeps flow stable so the system can meter DEF correctly.\u003c\/li\u003e\n\u003cli\u003eSupports proper SCR operation and emissions control.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e4. Reduces waste and improves efficiency\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eReuses excess DEF instead of losing it.\u003c\/li\u003e\n\u003cli\u003eHelps maintain consistent fluid supply in the system.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e5. Helps prevent clogging and crystallization\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eKeeps DEF moving instead of sitting in lines.\u003c\/li\u003e\n\u003cli\u003eReduces the chance of DEF forming crystals inside components.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003e\u003cbr\u003eSigns of Faulty:\u003cbr\u003e\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003ctable width=\"100%\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e \n\u003cp\u003e\u003cstrong\u003e1. DEF leaks or white crystals\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eWet spots or dried white crust around the tube or fittings\u003c\/li\u003e\n\u003cli\u003eCrystallized DEF buildup (chalky white residue)\u003c\/li\u003e\n\u003cli\u003eOften caused by cracks or loose connections\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e2. SCR or DEF system warning lights\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eCheck engine light on\u003c\/li\u003e\n\u003cli\u003e“SCR system fault” or “DEF system malfunction” messages\u003c\/li\u003e\n\u003cli\u003eEmissions-related trouble codes\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e3. Pressure or dosing faults\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eLow DEF pressure or unstable pressure readings\u003c\/li\u003e\n\u003cli\u003e“DEF dosing performance” or “injection system fault” codes\u003c\/li\u003e\n\u003cli\u003eSystem may struggle to maintain correct flow balance\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e4. Abnormal DEF usage\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eDEF consumption higher or lower than normal\u003c\/li\u003e\n\u003cli\u003eInconsistent DEF level changes in the tank\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e5. Poor engine performance (derate)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eReduced engine power\u003c\/li\u003e\n\u003cli\u003eSpeed limitation due to emissions faults\u003c\/li\u003e\n\u003cli\u003eOccurs when SCR system cannot operate correctly\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e6. Pump or injector strain\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eDoser pump running more often than usual\u003c\/li\u003e\n\u003cli\u003eNoisy operation or frequent cycling\u003c\/li\u003e\n\u003cli\u003eInjector may clog due to improper return flow\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e7. Crystallization inside the system\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eBlockage forming in return line or nearby fittings\u003c\/li\u003e\n\u003cli\u003eDEF backing up and drying inside components\u003c\/li\u003e\n\u003cli\u003eCan spread to injector or dosing unit\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003e\u003cbr\u003e\u003cbr\u003eNavistar International Corporation\u003c\/strong\u003e is an American company specializing in the production of trucks, buses, diesel engines and other transport equipment. They are known for their products for various industries including logistics, construction and public transport. The company is also actively working on the development of electric and hybrid solutions for the transport industry.\u003c\/span\u003e\u003c\/p\u003e","brand":"International","offers":[{"title":"Default Title","offer_id":48751552495860,"sku":"4067677C2","price":98.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0605\/1479\/5764\/files\/Truck-parts_-ftp_2048x2048_2048x2048_4_1000x1000_7ee5b8f8-a107-464c-b111-a9c6fca38002.jpg?v=1781894591","url":"https:\/\/firsttruckparts.com\/en-ca\/products\/4067677c2-genuine-international%c2%ae-def-return-tube","provider":"First Truck Parts","version":"1.0","type":"link"}