{"product_id":"mmx-performance-bmw-billet-coolant-expansion-cap","title":"MMX Performance BMW Billet Coolant Expansion Cap","description":"\u003cp\u003eThe \u003ca href=\"https:\/\/ind-distribution.com\/collections\/mmx-performance\"\u003eMMX Performance\u003c\/a\u003e BMW Billet Coolant Expansion Cap is a precision-engineered replacement designed to improve both the durability and appearance of your BMW's cooling system. Unlike decorative cap covers, this is a complete OE replacement that fully replaces the factory plastic coolant expansion cap while retaining all factory pressure regulation and sealing functionality.\u003c\/p\u003e\n\n\u003cp\u003eFactory coolant caps are subjected to constant heat cycles and pressure fluctuations, which can cause plastic components to degrade over time. The MMX Billet Coolant Expansion Cap addresses this with a robust construction CNC-machined from a solid block of 6061 aerospace-grade aluminum, providing superior strength, heat resistance, and long-term reliability while adding a premium OEM+ appearance to the engine bay.\u003c\/p\u003e\n\n\u003cp\u003eEach cap is manufactured using advanced 5-axis CNC machining before receiving a durable gloss black anodized finish for excellent corrosion resistance and long-lasting appearance. The precision-machined exterior also provides improved grip, making installation and removal easier during routine coolant service.\u003c\/p\u003e\n\n\u003cp\u003eUnlike many aftermarket alternatives, the MMX Billet Coolant Expansion Cap arrives pre-assembled with OE-spec internal components, including the pressure valve, internal spring, and high-quality Viton O-ring seal. No parts need to be transferred from the original cap, allowing for a simple direct replacement while maintaining proper cooling system pressure and sealing performance.\u003c\/p\u003e\n\n\u003cp\u003eAvailable in both 60mm and 90mm versions, the MMX Performance BMW Billet Coolant Expansion Cap replaces BMW OE part numbers \u003cstrong\u003e17117639024 (60mm)\u003c\/strong\u003e and \u003cstrong\u003e17117639021 (90mm)\u003c\/strong\u003e. Please verify the part number on the underside of your existing coolant cap prior to ordering.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eProduct Details\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eMMX Performance billet coolant expansion cap for BMW\u003c\/li\u003e\n\u003cli\u003eAvailable in 60mm and 90mm fitments\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eReplaces BMW OE part numbers 17117639024 (60mm) and 17117639021 (90mm)\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003eDirect OE replacement with factory-style internals pre-installed\u003c\/li\u003e\n\u003cli\u003ePre-installed pressure valve, internal spring, and Viton O-ring seal\u003c\/li\u003e\n\u003cli\u003eCNC-machined from 6061 aerospace-grade aluminum\u003c\/li\u003e\n\u003cli\u003eAdvanced 5-axis machining for precise fitment\u003c\/li\u003e\n\u003cli\u003eGloss black anodized finish for corrosion resistance and OEM+ appearance\u003c\/li\u003e\n\u003cli\u003ePrecision-machined grip design for easier installation and removal\u003c\/li\u003e\n\u003cli\u003eImproves durability compared to the factory plastic coolant cap\u003c\/li\u003e\n\u003cli\u003eNo transfer of OEM components required\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eRecommended Products\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/ind-distribution.com\/products\/mmr-performance-bmw-billet-oil-filler-cap-s58-b48e\" target=\"_blank\"\u003eMMX Performance BMW Billet Oil Filler Cap – S58 \/ B48E\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/ind-distribution.com\/products\/mmr-performance-bmw-billet-oil-filler-cap\" target=\"_blank\"\u003eMMX Performance BMW Billet Oil Filler Cap\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"MMX Performance","offers":[{"title":"90mm Cap (Replaces OE Part 17117639021) | MMR03-1502","offer_id":51457199440036,"sku":"MMR03-1502","price":182.61,"currency_code":"CAD","in_stock":true},{"title":"60mm Cap (Replaces OE Part 17117639024) | MMR03-1503","offer_id":51457199472804,"sku":"MMR03-1503","price":182.61,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0013\/9929\/1964\/files\/mmx-bmw-billet-coolant-expansion-cap-90mm-black-anodized-white-background.jpg?v=1787760345","url":"https:\/\/www.amtuning.ca\/products\/mmx-performance-bmw-billet-coolant-expansion-cap","provider":"AM Tuning Canada","version":"1.0","type":"link"}