{"product_id":"dorman-m630070-brake-master-cylinder","title":"Dorman M630070 Brake Master Cylinder","description":"\u003ch2\u003eDorman M630070 Brake Master Cylinder\u003c\/h2\u003e\u003cp\u003eThe Dorman M630070 brake master cylinder is a direct replacement for select BMW applications that require a 21 mm bore. Built from new aluminum materials, it is engineered to match the original master cylinder’s design, function, and performance for dependable brake hydraulic operation.\u003c\/p\u003e\u003cp\u003eUse this brake master cylinder for BMW 525i, 530i, 540i, M5, 740i, 740iL, 750iL, and X5 applications listed below. The M630070 is a practical OE-style replacement when the original unit is worn, leaking, or no longer maintaining proper pedal feel.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e21 mm master cylinder bore diameter\u003c\/li\u003e\n\u003cli\u003eAluminum master cylinder construction\u003c\/li\u003e\n\u003cli\u003eThree outlet ports\u003c\/li\u003e\n\u003cli\u003eNew, high-quality replacement materials\u003c\/li\u003e\n\u003cli\u003ePackage includes master cylinder only\u003c\/li\u003e\n\u003cli\u003eNo reservoir included\u003c\/li\u003e\n\u003cli\u003eNo sensor included\u003c\/li\u003e\n\u003cli\u003eMounting hardware not included\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eDetailed Product Information\u003c\/h2\u003e\u003cp\u003eThis brake master cylinder is built to match the original hydraulic layout on specific BMW models, including 2003 BMW 525i, 2001-2003 BMW 530i, 2003 BMW 540i, 2003 BMW M5, 2001-2002 BMW 540i, 2000-2002 BMW M5, 1999-2001 BMW 740i, 1999-2001 BMW 740iL, 1999-2001 BMW 750iL, 2001 BMW X5, and 2000 BMW X5. It features rearward outlet sizes of M10 x 1.0 and M10 x 1.0, plus a secondary outlet thread diameter of M12 x 1.0 with 1.0 thread pitch. This part cross-references Raybestos Brakes MC390633 for the same application.\u003c\/p\u003e\u003cp\u003eFor shoppers searching for a BMW brake master cylinder 21 mm bore, BMW 540i master cylinder replacement, or BMW X5 brake master cylinder M630070, this part provides the correct hydraulic configuration for the listed vehicles. It is also a fitment-based replacement for BMW 740i and BMW M5 brake system service where the 21 mm bore specification is required.\u003c\/p\u003e\u003ch2\u003eWhat It Helps Address\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eSoft or inconsistent brake pedal feel\u003c\/li\u003e\n\u003cli\u003eBrake fluid leakage from a worn master cylinder\u003c\/li\u003e\n\u003cli\u003eLoss of hydraulic pressure in the brake system\u003c\/li\u003e\n\u003cli\u003eInternal seal wear affecting braking response\u003c\/li\u003e\n\u003cli\u003eReplacement needs after master cylinder failure\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes and Tips\u003c\/h2\u003e\u003cp\u003eConfirm the vehicle’s bore size, outlet thread sizes, and fitment notes before installation. This unit does not include a reservoir, sensor, or mounting hardware, so reuse or source those components as needed. Proper brake bleeding is required after installation to remove air from the hydraulic system and restore pedal firmness.\u003c\/p\u003e\u003ch2\u003eQuality Assurance\u003c\/h2\u003e\u003cp\u003eDorman manufactures this master cylinder as a new replacement part using high-quality materials and OE-style engineering for the listed BMW applications. The M630070 is built to match original design and performance requirements for brake hydraulic service.\u003c\/p\u003e","brand":"Dorman","offers":[{"title":"Default Title","offer_id":52401882235061,"sku":"BKKX-M630070","price":217.43,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/DB_M630070_Fro.jpg?v=1777760013","url":"https:\/\/www.partcatalog.com\/products\/dorman-m630070-brake-master-cylinder","provider":"PartCatalog","version":"1.0","type":"link"}