Rebuild Kit 7/8

The Wilwood Rebuild Kit 7/8 in Bore (MPN 260-6899) is a complete restoration solution for Wilwood master cylinders featuring a 7/8-inch bore diameter. This kit is essential for mechanics and performance enthusiasts who maintain or upgrade hydraulic brake systems on street rods, classic cars, custom builds, and high-performance vehicles. A master cylinder rebuild becomes necessary when internal seals wear, the piston develops corrosion or scoring, or brake fluid fails to build proper pressure—symptoms that demand a full internal restoration rather than costly component replacement.

This rebuild kit contains all critical internal components: precision-machined piston, primary and secondary seals designed to maintain hydraulic integrity, snap ring for secure retention, pushrod for brake pedal coupling, and dust boot plus lid gasket to protect against contamination and fluid loss. The 7/8-inch bore specification matches Wilwood's mid-capacity master cylinder platform, making it compatible with brake systems designed for vehicles ranging from vintage hot rods to modern performance cars requiring moderate to higher brake line pressures. Each component is engineered to OEM tolerances, ensuring reliable sealing and smooth pedal feel after installation—critical factors that directly impact stopping power and driver confidence.

Brake technicians, restoration shops, and DIY builders benefit most from keeping this kit in inventory for field repairs or planned maintenance during brake system overhauls. Installation requires basic mechanical skills: remove the master cylinder from the vehicle, disassemble the housing, and replace worn seals and internal parts with those included in the kit. Weighing just 0.68 lbs and measuring 6.75 inches in length, the compact kit ships efficiently and stores easily on any workbench. Compatibility is limited to Wilwood 7/8-inch bore master cylinders; verify bore diameter before purchase to ensure proper fit and function of all components.