{"product_id":"dorman-m39309-brake-master-cylinder","title":"Dorman M39309 Brake Master Cylinder","description":"\u003ch2\u003eReliable Brake Master Cylinder for Chevrolet and GMC Trucks\u003c\/h2\u003e\u003cp\u003eThe Dorman M39309 brake master cylinder is engineered to restore proper brake hydraulics for Chevrolet and GMC heavy-duty trucks. Designed specifically for models like the Chevrolet C3500 and GMC P3500, this master cylinder ensures consistent brake fluid pressure and reliable stopping power.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eMaster cylinder bore diameter: 34 mm for precise hydraulic control\u003c\/li\u003e\n\u003cli\u003eConstructed from durable cast iron for long-lasting performance\u003c\/li\u003e\n\u003cli\u003eIncludes reservoir for brake fluid, simplifying installation\u003c\/li\u003e\n\u003cli\u003eTwo outlets with rearward outlet size of 9\/16-18 and secondary outlet thread diameter of 0.5 inches\u003c\/li\u003e\n\u003cli\u003ePackage contains the master cylinder only; mounting hardware not included\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eTechnical Details and Compatibility\u003c\/h2\u003e\u003cp\u003eThe Dorman M39309 brake master cylinder is built with a 34 mm bore diameter, providing the correct hydraulic pressure needed for the brake systems on Chevrolet C3500, GMC G30, P30, and P3500 models. Its cast iron construction offers durability and resistance to wear under demanding conditions. The included reservoir allows for proper brake fluid containment, while the two outlets—featuring a rearward outlet size of 9\/16-18 and a secondary outlet thread diameter of 0.5 inches—ensure compatibility with the vehicle’s brake lines. This part does not include mounting hardware or sensors, so those components must be sourced separately if needed.\u003c\/p\u003e\u003ch2\u003eCommon Applications and Problem Resolution\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eRestores brake fluid pressure in Chevrolet C3500 and GMC P3500 brake systems\u003c\/li\u003e\n\u003cli\u003eReplaces worn or leaking master cylinders causing brake pedal sponginess\u003c\/li\u003e\n\u003cli\u003eAddresses brake fluid reservoir leaks or contamination issues\u003c\/li\u003e\n\u003cli\u003eSolves inconsistent braking performance due to master cylinder failure\u003c\/li\u003e\n\u003cli\u003ePrevents brake system failure from internal seal wear or corrosion\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes and Tips\u003c\/h2\u003e\u003cp\u003eWhen installing the Dorman M39309 brake master cylinder, ensure the brake fluid reservoir is properly filled and free of contaminants. Bleed the brake system thoroughly to remove air pockets and verify that the two outlets are securely connected to the brake lines with compatible fittings. Since mounting hardware is not included, retain the original hardware or acquire appropriate replacements. Verify compatibility with Chevrolet C3500, GMC G30, P30, and P3500 models before installation.\u003c\/p\u003e\u003ch2\u003eQuality Assurance and Warranty\u003c\/h2\u003e\u003cp\u003eDorman manufactures the M39309 brake master cylinder to meet or exceed OEM specifications for fit, form, and function. The cast iron construction and precise bore diameter contribute to reliable brake system performance. While specific warranty details are not provided here, Dorman typically offers limited warranties on their brake hydraulics products to ensure customer confidence and product reliability.\u003c\/p\u003e","brand":"Dorman","offers":[{"title":"Default Title","offer_id":43789335396533,"sku":"BKKX-M39309","price":106.59,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/DB_M39309_Fro.jpg?v=1774997464","url":"https:\/\/www.partcatalog.com\/products\/dorman-m39309-brake-master-cylinder","provider":"PartCatalog","version":"1.0","type":"link"}