Reservoir 4oz Billet Bare w/o Cap

The Wilwood Reservoir 4oz Billet Bare without Cap is a compact remote master cylinder reservoir engineered for custom brake system builds and performance vehicle conversions. Built from precision-machined aluminum, this 4.0-ounce capacity unit serves vehicles requiring remote fluid storage away from traditional under-hood locations—common in race cars, heavily modified street vehicles, and purpose-built track machines where space constraints or custom layouts demand alternative master cylinder configurations. This bare aluminum design integrates seamlessly into custom hydraulic brake setups where OEM reservoir placement interferes with intake manifolds, turbochargers, or other engine modifications.

Constructed from billet aluminum, the reservoir offers weight savings and corrosion resistance compared to cast-iron alternatives while maintaining structural rigidity required for hydraulic system pressures. The compact 4.05 x 2.8 x 4.85-inch footprint allows installation in tight engine bays or interior locations where space efficiency is critical—particularly valuable in vintage restorations, mid-engine conversions, and race vehicle builds. The bare finish (without cap) provides flexibility for custom mounting brackets and fluid-level indicator integration, allowing builders to add caps, sight glasses, or remote fill ports tailored to their specific brake system design and installation geometry.

This Wilwood reservoir pairs with compact remote master cylinders in performance braking applications where conventional brake proportioning and master cylinder placement cannot be accommodated. Brake system builders, fabricators, and enthusiasts working on high-performance street cars, tube-frame race vehicles, and custom hot rods benefit from Wilwood's engineered approach to hydraulic component integration. Verify compatibility with your specific master cylinder model and brake line routing before installation; the 4-ounce capacity suits applications requiring remote fluid storage for single or dual-circuit brake systems operating at road-course or racing pressures.