Square O-Ring Kit - 1.38

The Square O-Ring Kit - 1.38 from Wilwood is an essential sealing component for high-performance brake systems and hydraulic assemblies. Mechanics working on everything from street cars to track builds understand that proper sealing is crucial—any leak in a brake or clutch system can compromise safety and performance. This kit supplies precision-engineered square O-rings that are compatible with Wilwood brake calipers, proportioning valves, and master cylinders.

Square O-rings differ from traditional round seals by distributing pressure more evenly across the gland surface, which reduces extrusion under high brake pressures and thermal cycling. The 1.38 dimension refers to the cross-sectional diameter, a common size across Wilwood's hydraulic component lineup. These seals are engineered to withstand the extreme temperature swings and pressure spikes inherent to performance braking.

Technicians rebuilding Wilwood brake calipers, master cylinders, or proportioning valves rely on this kit to restore OEM sealing integrity without replacing entire assemblies. Whether you're maintaining factory equipment or upgrading your braking system, this kit ensures consistent performance and reliability. Trust in Wilwood's quality control for consistent durometer and material composition, so every seal in the kit performs identically.