{"product_id":"dorman-m390186-brake-master-cylinder","title":"Dorman M390186 Brake Master Cylinder","description":"\u003ch2\u003eReliable Brake Master Cylinder for Buick, Cadillac, Oldsmobile, and Pontiac\u003c\/h2\u003e\u003cp\u003eThe Dorman M390186 Brake Master Cylinder is engineered to restore proper brake hydraulics in select Buick, Cadillac, Oldsmobile, and Pontiac models. Designed with precision, this master cylinder ensures consistent brake fluid pressure for safe and responsive braking performance.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eMaster cylinder bore diameter: 1 inch for accurate fluid displacement\u003c\/li\u003e\n\u003cli\u003eConstructed from durable aluminum material for corrosion resistance\u003c\/li\u003e\n\u003cli\u003eIncludes reservoir and sensor for complete brake system integration\u003c\/li\u003e\n\u003cli\u003eTwo outlet ports with rearward outlet size M10 x 1.0 and secondary outlet thread diameter M12 x 1.0\u003c\/li\u003e\n\u003cli\u003eThread pitch of 1.0 for secure and proper fitting\u003c\/li\u003e\n\u003cli\u003ePackage contains the master cylinder unit; mounting hardware not included\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eDetailed Product Features and Specifications\u003c\/h2\u003e\u003cp\u003eThe Dorman M390186 master cylinder is crafted from aluminum, providing a lightweight yet robust component that resists corrosion and wear. Its 1-inch bore diameter is designed to deliver precise hydraulic pressure, essential for the braking systems of vehicles such as the Buick LeSabre, Cadillac DeVille, Oldsmobile 88, and Pontiac Bonneville. The included reservoir and sensor facilitate seamless integration with the vehicle’s brake fluid monitoring system, ensuring timely alerts for fluid levels. Featuring two outlets, the master cylinder supports dual-circuit brake systems, with outlet sizes tailored for secure connections: a rearward outlet sized M10 x 1.0 and a secondary outlet with M12 x 1.0 threading. This part is identified by part number M390186 and is compatible with models including the Buick Park Avenue, Cadillac Fleetwood, Oldsmobile Delta 88, and Pontiac Riviera.\u003c\/p\u003e\u003ch2\u003eCommon Applications and Problem Resolution\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eRestores brake fluid pressure in vehicles experiencing spongy or unresponsive brakes\u003c\/li\u003e\n\u003cli\u003eReplaces master cylinders with leaking or damaged reservoirs\u003c\/li\u003e\n\u003cli\u003eAddresses brake warning light activation due to faulty sensors\u003c\/li\u003e\n\u003cli\u003eSolves issues related to inconsistent brake pedal feel or travel\u003c\/li\u003e\n\u003cli\u003eSupports brake system repairs in Buick, Cadillac, Oldsmobile, and Pontiac models listed\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes and Tips\u003c\/h2\u003e\u003cp\u003eInstallation of the Dorman M390186 master cylinder requires proper brake system bleeding to remove air and ensure optimal hydraulic function. Note that mounting hardware is not included, so retain original fasteners or acquire appropriate replacements. Verify thread pitch and outlet sizes (M10 x 1.0 and M12 x 1.0) to ensure compatibility with existing brake lines. Sensor connections should be carefully reattached to maintain brake fluid level monitoring. Professional installation is recommended for accurate fitment and safety compliance.\u003c\/p\u003e\u003ch2\u003eQuality Assurance and Warranty Information\u003c\/h2\u003e\u003cp\u003eDorman manufactures the M390186 master cylinder to meet or exceed OEM specifications for the specified Buick, Cadillac, Oldsmobile, and Pontiac models. The aluminum construction and integrated sensor contribute to long-term reliability. While mounting hardware is not included, the product undergoes rigorous quality control to ensure proper function upon installation. Warranty coverage details should be confirmed with the distributor or manufacturer to understand terms and conditions.\u003c\/p\u003e","brand":"Dorman","offers":[{"title":"Default Title","offer_id":43792119103669,"sku":"BKKX-M390186","price":63.15,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/DB_M390186_Fro_9315e05a-0b6e-4b7e-bdeb-f54ea102c7f4.jpg?v=1774997555","url":"https:\/\/www.partcatalog.com\/products\/dorman-m390186-brake-master-cylinder","provider":"PartCatalog","version":"1.0","type":"link"}