7/8 Rebuild Kit

The Wilwood 7/8 Rebuild Kit (MPN 260-3882) is a complete master cylinder seal and component set engineered for serious brake system maintenance and modification work. Whether you're restoring a classic muscle car, upgrading to a high-performance braking platform, or refreshing worn hydraulic components on your daily driver, this rebuild kit supplies all the internal wear items needed to restore your Wilwood master cylinder to factory specifications. The 7/8-inch bore size covers a wide range of applications, from street performance builds to track-oriented setups where brake feel and response are critical.

This kit includes precision-cut seals, a replacement piston, a dust boot, and a snap ring—all the internal hardware required to eliminate brake fade caused by deteriorated seals and worn elastomers. Over time, hydraulic fluid exposure and heat cycling degrade OEM seals, reducing system pressure consistency and creating a spongy pedal feel that compromises stopping power. Wilwood's rebuild components are manufactured to exacting tolerances, ensuring proper seal engagement and fluid containment without excessive drag or leakage. The included dust boot protects internal components from contamination, while the snap ring maintains proper component retention and eliminates rattling or movement during aggressive braking events.

Technicians and enthusiasts rebuilding Wilwood master cylinders benefit from having all necessary seals and hardware in one compact, organized kit—eliminating multiple part orders and ensuring compatibility. Installation requires basic mechanical skill and standard shop tools; most rebuilds can be completed in under an hour. This kit is ideal for anyone performing brake system maintenance, converting to a custom hydraulic setup, or simply restoring original brake performance on vintage or modified vehicles. Compact at just 0.3 lbs, the 7/8 Rebuild Kit fits easily in any garage or tool drawer for quick access when maintenance is needed.