{"product_id":"dorman-brake-master-cylinder-for-chevrolet-gmc-trucks-m39646-aluminum-direct-fit-replacement","title":"Dorman Brake Master Cylinder for Chevrolet GMC Trucks M39646 — Aluminum, Direct-Fit Replacement","description":"\u003cstrong\u003eThe Dorman M39646 brake master cylinder is a 100% new aluminum replacement engineered to restore original braking function on compatible Chevrolet, GMC, and select Dodge models.\u003c\/strong\u003e\n\nThis master cylinder is built to match the original unit’s design and performance while using new materials for durability and safety. It replicates the factory casting characteristics and employs EPDM rubber components formulated to resist glycol-based brake fluids. Before ordering, confirm compatibility by entering your vehicle year, make, and trim in the garage tool—this ensures the part matches the exact application.\n\n\u003ch3\u003eHow does this master cylinder replicate the factory part?\u003c\/h3\u003e\n\u003cp\u003eThe M39646 is manufactured to mirror the original housing’s geometry and casting material so it installs and operates like the OE piece. Internal bore dimensions, port locations, and mounting points are produced to the same form and function standards used in the original equipment.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eAluminum cylinder housing matched to original casting characteristics\u003c\/li\u003e\n  \u003cli\u003ePrecisely located ports and mounting flanges for direct-fit installation\u003c\/li\u003e\n  \u003cli\u003eDesigned to meet SAE International manufacturing and dimensional standards\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat materials and components ensure long life?\u003c\/h3\u003e\n\u003cp\u003eThis unit is assembled from entirely new parts rather than remanufactured cores, reducing the risk of concealed wear. All rubber seals and boots are made from EPDM compound, chosen for its compatibility with common glycol-based brake fluids and resistance to swelling and deterioration.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e100% new construction — no remanufactured parts\u003c\/li\u003e\n  \u003cli\u003eEPDM rubber components for fluid compatibility and longevity\u003c\/li\u003e\n  \u003cli\u003eCorrosion-resistant aluminum housing to reduce long-term wear\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhich vehicles is the Dorman M39646 compatible with?\u003c\/h3\u003e\n\u003cp\u003eThis master cylinder fits a range of late-1980s to mid-1990s Chevrolet and GMC full-size trucks and SUVs, plus a specific Dodge Ram 1500 year. Fitment varies by model and trim—use the garage tool to confirm the right application before purchasing.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCompatible with Chevrolet C\/K 1500 and 2500 series trucks and Suburbans (1988–1994, depending on model)\u003c\/li\u003e\n  \u003cli\u003eCompatible with GMC C\/K 1500 and 2500 series trucks and Yukons\/Suburbans (1988–1994, depending on model)\u003c\/li\u003e\n  \u003cli\u003eAlso lists Dodge Ram 1500 for 1994—verify trim for proper fit\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat should I expect during installation and maintenance?\u003c\/h3\u003e\n\u003cp\u003eInstallation is intended to be straightforward for a professional technician or an experienced DIYer with the correct tools. Bleed the brake system following manufacturer procedures after installation, and inspect for leaks around ports and fittings during the first road test.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDirect-fit design reduces machining or modification during installation\u003c\/li\u003e\n  \u003cli\u003eRequires standard brake-bleeding procedures post-installation\u003c\/li\u003e\n  \u003cli\u003eInspect seal surfaces and reservoir interface for secure sealing\u003c\/li\u003e\n\u003c\/ul\u003e\n\nWho is this for? The Dorman M39646 is aimed at owners and technicians restoring braking performance on compatible Chevrolet and GMC trucks and SUVs from the late 1980s through the mid-1990s, plus the listed Dodge Ram 1500 year. It suits vehicles needing a non-remanufactured, factory-style master cylinder replacement that emphasizes material quality, correct fit, and resistance to brake fluid degradation. If you require a reliable, direct-fit replacement built to SAE specifications, this unit is a practical, long-lasting choice. Remember to verify fitment in the garage tool for your exact year, make, and trim before purchase.\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 master cylinder new or remanufactured?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: The Dorman M39646 is 100% new construction, not remanufactured, using new aluminum and EPDM components.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: How do I confirm this part fits my truck?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Enter your vehicle year, make, and trim into the garage fitment tool to verify compatibility before purchasing.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Dorman","offers":[{"title":"Default Title","offer_id":48086775169182,"sku":"B001PYTL28","price":61.67,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/dorman-m39646-front-view.jpg?v=1785904622","url":"https:\/\/northtrailauto.ca\/products\/dorman-brake-master-cylinder-for-chevrolet-gmc-trucks-m39646-aluminum-direct-fit-replacement","provider":"North Trail Auto","version":"1.0","type":"link"}