{"product_id":"dorman-m390591-brake-master-cylinder","title":"Dorman M390591 Brake Master Cylinder","description":"\u003ch2\u003eBrake Master Cylinder for Honda Civic\u003c\/h2\u003e\u003cp\u003eThis Dorman brake master cylinder is built for 1999-2000 Honda Civic models with drum brake wheel cylinders that require a 7\/8 in. bore size. Part number M390591 is engineered to match the original master cylinder’s design, function, and performance using new, high-quality materials.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eDirect replacement brake master cylinder for specific Honda Civic applications\u003c\/li\u003e\n\u003cli\u003e0.875 in. bore diameter for the listed fitment\u003c\/li\u003e\n\u003cli\u003eAluminum master cylinder construction\u003c\/li\u003e\n\u003cli\u003eReservoir included for a complete hydraulic assembly\u003c\/li\u003e\n\u003cli\u003eSensor included\u003c\/li\u003e\n\u003cli\u003eTwo outlet design with M10 x 1.0 rearward outlet thread\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eOE-Style Hydraulic Replacement\u003c\/h2\u003e\u003cp\u003eDorman M390591 is a brake master cylinder designed to restore hydraulic pressure at the brake pedal and support consistent brake system operation. It is a fitment-specific replacement for 1999-2000 Honda Civic, and the 7\/8 in. bore size matches the application noted for drum brake wheel cylinders. This part cross-references Raybestos Brakes MC390591 for the same application.\u003c\/p\u003e\u003ch2\u003eCommon Issues This Part Addresses\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eLow or inconsistent brake pedal pressure\u003c\/li\u003e\n\u003cli\u003eInternal master cylinder leakage\u003c\/li\u003e\n\u003cli\u003eBrake fluid loss at the hydraulic unit\u003c\/li\u003e\n\u003cli\u003eUneven brake response from a worn master cylinder\u003c\/li\u003e\n\u003cli\u003eBrake warning sensor-related replacement needs\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\u003cp\u003eMounting hardware is not included. Before installation, verify the bore size, outlet thread size, and reservoir\/sensor configuration against the original unit. Bench bleed the master cylinder before connecting brake lines, then bleed the full brake system after installation. Confirm the vehicle is a 1999-2000 Honda Civic with the listed drum brake wheel cylinder application before ordering M390591.\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 application-specific engineering to match the original unit’s design and performance for the listed Honda Civic fitment.\u003c\/p\u003e","brand":"Dorman","offers":[{"title":"Default Title","offer_id":52431298396341,"sku":"BKKX-M390591","price":118.34,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/DB_M390591_Fro.jpg?v=1777853371","url":"https:\/\/www.partcatalog.com\/products\/dorman-m390591-brake-master-cylinder","provider":"PartCatalog","version":"1.0","type":"link"}