{"product_id":"dorman-diesel-exhaust-fluid-def-filler-cap-for-freightliner-cascadia-2010-2020-direct-fit-durable-polymer-seal","title":"Dorman Diesel Exhaust Fluid (DEF) Filler Cap for Freightliner Cascadia 2010–2020 — Direct-Fit, Durable Polymer Seal","description":"\u003cp\u003e\u003cstrong\u003eThe Dorman 904-5201CD Diesel Exhaust Fluid (DEF) filler cap is a direct-fit replacement engineered to restore a secure, leak-free seal on compatible Freightliner Cascadia models from 2010–2020.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIf the DEF cap on your Freightliner is cracked, worn, or no longer seals properly, this Dorman replacement restores proper containment and protects the DEF reservoir from contamination and evaporation. Built from durable materials and designed to match the original cap's fit and function, it makes a straightforward service item for fleet managers, owner-operators, and independent repair shops. Always verify fitment with your vehicle details using the garage tool before ordering.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this cap replace the original DEF filler cap?\u003c\/h3\u003e\n\u003cp\u003eThe 904-5201CD is manufactured to the same dimensions and sealing profile as the OE cap for the specified Cascadia years, allowing it to clip or thread into the original filler neck without modification. That ensures a secure mechanical fit and restores the original closure action drivers expect.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDirect replacement geometry for Freightliner Cascadia (2010–2020)\u003c\/li\u003e\n  \u003cli\u003eSame sealing interface to prevent DEF leaks\u003c\/li\u003e\n  \u003cli\u003eInstallable using the existing filler neck and mounting points\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat materials and durability features does the cap offer?\u003c\/h3\u003e\n\u003cp\u003eThis filler cap is molded from robust polymers formulated for automotive fluids and exterior exposure. The construction resists common failure modes such as cracking from vibration, UV degradation, and chemical exposure from DEF, offering reliable service life when compared to aged or damaged originals.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDurable polymer construction for long-term use\u003c\/li\u003e\n  \u003cli\u003eResistant to DEF chemical exposure and environmental stress\u003c\/li\u003e\n  \u003cli\u003eDesigned to maintain seal under typical operating vibrations\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow easy is it to install and verify fitment?\u003c\/h3\u003e\n\u003cp\u003eInstallation is typically quick and non-technical: remove the old cap and press or thread the Dorman cap into the filler neck until it seats. For peace of mind, use the product page garage tool to confirm vehicle compatibility; hover over any blue \"i\" icons for additional fitment notes.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSimple remove-and-replace installation process\u003c\/li\u003e\n  \u003cli\u003eUse the online garage tool to confirm fit before purchase\u003c\/li\u003e\n  \u003cli\u003eCheck for an \"i\" in a blue circle for extra fitment details\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this cap prevent DEF contamination and leaks?\u003c\/h3\u003e\n\u003cp\u003eWhile no cap can fully eliminate contamination risk, a properly sealing DEF filler cap significantly reduces the chance of foreign particles or moisture entering the reservoir and minimizes DEF loss from evaporation or spillage. Replacing a damaged cap is a practical step to maintain DEF system integrity.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eReplaces cracked or worn caps that allow contamination\u003c\/li\u003e\n  \u003cli\u003eImproves reservoir sealing to reduce evaporation and spillage\u003c\/li\u003e\n  \u003cli\u003eHelps maintain DEF quality between service intervals\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: This Dorman 904-5201CD DEF filler cap is intended for Freightliner Cascadia owners and technicians who need a reliable, OEM-style replacement for models from 2010 through 2020. It's a straightforward, cost-effective part for fleet maintenance, roadside repairs, or preventative replacement during DEF system service. Remember to confirm fitment with your vehicle trim in the garage tool before purchasing to ensure compatibility.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Is the Dorman 904-5201CD compatible with my Freightliner Cascadia?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: It fits Freightliner Cascadia models from 2010–2020; confirm exact trim using the garage tool and any blue \"i\" fitment notes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I install this cap myself?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. It’s a simple remove-and-replace job using the existing DEF filler neck; no special tools are typically required.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Dorman","offers":[{"title":"Default Title","offer_id":48084338507934,"sku":"B019IO2T2K","price":34.78,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/dorman-def-filler-cap-front-view.jpg?v=1785850664","url":"https:\/\/northtrailauto.ca\/products\/dorman-diesel-exhaust-fluid-def-filler-cap-for-freightliner-cascadia-2010-2020-direct-fit-durable-polymer-seal","provider":"North Trail Auto","version":"1.0","type":"link"}