{"product_id":"bsnovt-radiator-overflow-hose-for-audi-a4-a5-2017-2021-direct-oem-replacement-8w0121081an-heat-resistant","title":"BSNOVT Radiator Overflow Hose for Audi A4\/A5 2017-2021 - Direct OEM Replacement 8W0121081AN, Heat-Resistant","description":"\u003cstrong\u003eBSNOVT Radiator Overflow Hose is a direct-fit coolant expansion tank bypass line designed to replace OEM 8W0121081AN on select Audi A4 and A5 models.\u003c\/strong\u003e\n\n\u003cp\u003eThis replacement coolant hose provides a durable route for excess engine coolant to flow from the cooling system to the overflow reservoir. Manufactured to withstand high engine temperatures and road vibrations, the BSNOVT line offers a straightforward swap for worn or cracked factory hoses. It’s sold as a single-piece kit and engineered to align with factory hose fittings and mounting points for a reliable, leak-resistant installation.\u003c\/p\u003e\n\n\u003ch3\u003eWill this hose fit my Audi A4 or A5?\u003c\/h3\u003e\n\u003cp\u003eThe BSNOVT radiator overflow hose is made for specific model years and trims to ensure correct fit and function. Confirm compatibility by matching your vehicle’s model year and drivetrain before purchase to avoid returns.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCompatible vehicles: Audi A4 (2017–2020)\u003c\/li\u003e\n  \u003cli\u003eAudi A4 Quattro (2017–2021)\u003c\/li\u003e\n  \u003cli\u003eAudi A4 allroad (2017–2020)\u003c\/li\u003e\n  \u003cli\u003eAudi A5 Quattro and A5 Sportback (2018–2020)\u003c\/li\u003e\n  \u003cli\u003eDirect OEM replacement for part number 8W0121081AN\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow durable and heat-resistant is this coolant bypass line?\u003c\/h3\u003e\n\u003cp\u003eThis hose is constructed from materials selected to resist heat, chemical exposure, and engine bay wear typical of modern turbocharged engines. The build quality aims to reduce the risk of premature cracking, swelling, or softening that can lead to leaks and coolant loss.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eHigh-temperature-resistant compound designed for engine environments\u003c\/li\u003e\n  \u003cli\u003eReinforced sections to handle pressure and vibrations\u003c\/li\u003e\n  \u003cli\u003eCorrosion- and coolant-resistant inner surface\u003c\/li\u003e\n  \u003cli\u003eFactory-matching connection points for secure sealing\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does installation work and what’s included?\u003c\/h3\u003e\n\u003cp\u003eThe product ships as one ready-to-install coolant hose intended for a direct swap with the factory line. Basic mechanical tools are usually sufficient for replacement; follow torque specs and hose clamp recommendations for a safe fit.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003ePackage contains one coolant overflow\/bypass hose\u003c\/li\u003e\n  \u003cli\u003eDesigned for bolt-on replacement of OEM 8W0121081AN\u003c\/li\u003e\n  \u003cli\u003eInstallation typically requires removing the old hose and securing the new one with factory-style clamps\u003c\/li\u003e\n  \u003cli\u003eProfessional installation recommended if you’re unsure about cooling-system procedures\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat performance should I expect after replacing the hose?\u003c\/h3\u003e\n\u003cp\u003eWhen properly installed, this hose restores the cooling system’s overflow path so excess coolant is routed correctly to the reservoir. That helps maintain intended coolant levels and reduces the chance of leaks or overheating caused by a damaged bypass line.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eRe-establishes correct coolant overflow routing\u003c\/li\u003e\n  \u003cli\u003eHelps prevent coolant loss and maintain engine operating temperature\u003c\/li\u003e\n  \u003cli\u003eReduces risk of overheating caused by failed or brittle factory hoses\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The BSNOVT Radiator Overflow Hose is intended for Audi owners and independent shops replacing a failed or aging coolant bypass hose on compatible A4 and A5 models. It’s suited for drivers seeking a direct OEM-equivalent replacement that meets original fitment, technicians performing routine cooling-system repairs, and anyone restoring cooling integrity after a leak or hose deterioration.\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: Does this replace OEM part 8W0121081AN?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. This BSNOVT hose is a direct replacement for OEM part number 8W0121081AN.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I install this myself?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Basic mechanical skill and simple hand tools are sufficient, but professional installation is recommended if unsure.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"BSNOVT","offers":[{"title":"Default Title","offer_id":67591371751609,"sku":"B0DRVBNJ66","price":71.13,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0822\/3765\/3177\/files\/bsnovt-front-view-hose.jpg?v=1790549025","url":"https:\/\/redleafauto.ca\/products\/bsnovt-radiator-overflow-hose-for-audi-a4-a5-2017-2021-direct-oem-replacement-8w0121081an-heat-resistant","provider":"Redleaf Auto","version":"1.0","type":"link"}