{"product_id":"gm-genuine-parts-def-tank-filler-cap-23138955-oem-fit-durable-seal-for-gm-diesel-vehicles","title":"GM GENUINE PARTS DEF Tank Filler Cap 23138955 — OEM Fit, Durable Seal for GM Diesel Vehicles","description":"\u003cp\u003e\u003cstrong\u003eGM Genuine Parts 23138955 is the original-equipment diesel emissions fluid (DEF) tank filler cap engineered to fit GM diesel vehicles and maintain the DEF system seal.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis DEF tank filler cap is a factory-validated replacement from GM Genuine Parts, made to the same specifications used during vehicle production. It restores a proper seal on the DEF reservoir, helps protect the fluid from contaminants and evaporation, and ensures the cap interfaces correctly with the vehicle’s fill neck and onboard sensors. The part is designed, tested, and supported by General Motors and may have been previously listed under ACDelco GM Original Equipment (OE).\u003c\/p\u003e\n\n\u003ch3\u003eHow does this cap preserve my DEF system?\u003c\/h3\u003e\n\u003cp\u003eThe GM Genuine Parts filler cap provides a precise fit that prevents moisture, dirt, and debris from entering the DEF tank while minimizing fluid loss from evaporation. A correct seal helps the vehicle’s dosing and exhaust aftertreatment systems perform as intended without false sensor readings caused by a loose or damaged cap.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eOE-matched dimensions for secure sealing against the fill neck\u003c\/li\u003e\n  \u003cli\u003eDurable materials resist chemical exposure from DEF\u003c\/li\u003e\n  \u003cli\u003eProper fit reduces risk of contamination and sensor errors\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this cap fit my GM truck or SUV?\u003c\/h3\u003e\n\u003cp\u003ePart number 23138955 is manufactured to GM’s original specifications and is intended for compatible GM diesel models. Always verify part compatibility using your vehicle’s VIN or consult a GM dealer or parts catalog to confirm fitment before purchase.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDesigned and validated by GM engineers for GM vehicles\u003c\/li\u003e\n  \u003cli\u003eCross-reference with your vehicle’s parts list or VIN\u003c\/li\u003e\n  \u003cli\u003eMay replace previously marketed ACDelco GM OE parts\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat are the practical benefits of using an OEM DEF cap?\u003c\/h3\u003e\n\u003cp\u003eChoosing an OEM GM cap ensures consistent fit and function with factory components and reduces the chance of leaks or sensor-related warnings caused by aftermarket mismatches. OEM parts also follow GM’s materials and testing standards so they resist DEF exposure and temperature changes better over time.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eReliable sealing to prevent fluid contamination\u003c\/li\u003e\n  \u003cli\u003eCompatibility with onboard monitoring and diagnostics\u003c\/li\u003e\n  \u003cli\u003eBacked by General Motors’ engineering and validation\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eAre there any safety or regulatory notes I should know?\u003c\/h3\u003e\n\u003cp\u003eDEF is a urea-based solution and should be stored and handled per manufacturer guidance. This GM Genuine Parts cap is a passive component; follow vehicle and DEF container warnings for safe handling. Note: product listings may carry regulatory notices—some states require consumer warnings about chemical exposures.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eHandle DEF with gloves if skin contact is a concern\u003c\/li\u003e\n  \u003cli\u003eAvoid mixing contaminants into the DEF reservoir\u003c\/li\u003e\n  \u003cli\u003eCheck local regulations and product labeling for specific warnings\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: This part is intended for owners, fleet managers, and technicians who maintain GM diesel vehicles and need a direct OE replacement for a worn, lost, or damaged DEF tank filler cap. It’s the right choice when you want an exact, factory-style fit to protect the DEF system and maintain vehicle reliability without custom modifications.\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 this cap compatible with all GM diesel models?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Compatibility varies. Confirm fit using your vehicle VIN or parts catalog; 23138955 fits specific GM diesel models validated by General Motors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I replace the DEF cap myself?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. Replacing the filler cap is typically simple: remove the old cap, inspect the fill neck, and install the OE cap until it seats securely.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"GM GENUINE PARTS","offers":[{"title":"Default Title","offer_id":48085904294046,"sku":"B085S6V1C1","price":48.99,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/gm-genuine-parts-def-cap-front-view.jpg?v=1785880249","url":"https:\/\/northtrailauto.ca\/products\/gm-genuine-parts-def-tank-filler-cap-23138955-oem-fit-durable-seal-for-gm-diesel-vehicles","provider":"North Trail Auto","version":"1.0","type":"link"}