{"product_id":"0005018215h-expansion-tank-cap","title":"Mercedes Sprinter Coolant Expansion Tank Cap – Hudson | Screw-On Type | #0005018215 (NCV3 \u0026 VS30)","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eDESCRIPTION:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003eA leaking or failed coolant expansion tank cap is one of the most overlooked causes of coolant loss on a Sprinter — and one of the cheapest fixes. The cap maintains system pressure, allows coolant to expand safely as temperatures rise, and seals the reservoir between service intervals. When it fails to hold pressure, the cooling system operates below spec, coolant boils at a lower temperature, and you lose fluid without an obvious leak anywhere in the system. This Hudson replacement screw-on expansion tank cap restores proper pressure regulation across NCV3 and VS30 Sprinter models.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eWhat This Part Does\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003eThe coolant expansion tank cap contains a two-way pressure valve — a pressure relief valve that opens when system pressure exceeds the rated threshold (typically 1.4 bar on these applications), and a vacuum valve that allows coolant to return to the reservoir as the engine cools. Together they maintain a stable, pressurized cooling circuit that raises the boiling point of the coolant and ensures consistent coolant level over time. A cap that no longer holds pressure causes the system to vent coolant prematurely, leading to gradual coolant loss and elevated operating temperatures.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eScrew-On Type — Verify Your Cap Style\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003eThis is the threaded screw-on type cap. Some Mercedes-Benz applications use a twist-tab cap with a different sealing mechanism. Always verify your existing cap style before ordering — the two types are not interchangeable.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eWhen to Replace\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003eReplace if your Sprinter is losing coolant with no visible external leak, if the cap seal is cracked or deformed, or as part of any cooling system service or expansion tank replacement. This is a low-cost preventive item worth replacing any time the cooling system is being serviced.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eFitment\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e2010–2018 Mercedes-Benz Sprinter 2500\/3500 – All Engines (NCV3)\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e2019–2024 Mercedes-Benz Sprinter 2500\/3500 – All Engines (VS30)\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e2007–2009 Dodge Sprinter 2500\/3500 – All Engines\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003eAlways verify your cap style and VIN before ordering. Contact us and we'll confirm fitment before you buy.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003ePart Numbers\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eMercedes OEM: 0005018215 \/ A0005018215 \/ 000-501-82-15\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eHudson: 66100\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eCross Reference: 2105010715, 2105010615, 2105010515, 2105010315\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eSKU: 0005018215H\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"BlueTec Sprinter Parts","offers":[{"title":"Default Title","offer_id":46635403608238,"sku":"0005018215H","price":16.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0657\/9077\/1374\/files\/0005018215H_graphic.png?v=1788064280","url":"https:\/\/shop.bluetecsprinterparts.com\/products\/0005018215h-expansion-tank-cap","provider":"BlueTec Sprinter Parts","version":"1.0","type":"link"}