5/8 Rebuild Kit

The Wilwood 5/8 Rebuild Kit is an essential maintenance component for owners and technicians rebuilding or servicing Wilwood master cylinders with a 5/8-inch bore diameter. This complete rebuild kit addresses the wear and degradation that naturally occurs in hydraulic brake systems over time, restoring seal integrity and brake pedal responsiveness. Whether you're performing a full system restoration on a classic car, street rod, or high-performance brake conversion, this kit provides all the internal components needed to bring a master cylinder back to factory specifications without requiring a complete unit replacement.

The kit includes precision-engineered piston assemblies, OEM-grade seals, a replacement dust boot, and a snap ring—everything required for a professional-level rebuild. The dust boot protects internal components from contamination and moisture, while the piston and seal assembly maintains consistent hydraulic pressure and eliminates sponginess at the brake pedal. Wilwood's engineering ensures that rebuilt cylinders deliver the same responsive braking characteristics as new units, critical for safety in both street and track applications. The compact kit dimensions (2.9 x 1.4 x 7.35 inches) make storage convenient, while the lightweight construction (0.21 lbs) reflects minimal material weight without sacrificing durability.

Technicians and automotive enthusiasts rebuilding Wilwood-equipped brake systems will find this kit indispensable for maintaining consistent pedal feel and hydraulic response. The rebuild approach offers significant cost savings compared to purchasing a new master cylinder while extending service life indefinitely. Installation requires basic mechanical tools and brake system knowledge; proper bench assembly and bench-bleeding procedures before vehicle installation ensure air-free operation and maximum brake performance. This kit is compatible exclusively with Wilwood master cylinders featuring the 5/8-inch bore specification and is ideal for custom brake conversions, restoration projects, and preventive maintenance on performance vehicles.