Wilwood Residual Pressure Valve 2 lb 1/8" NPT Blue Anodized Aluminum with 3/8-24 Flare Fittings

The Wilwood residual pressure valve is a compact 2 lb spring-return valve for disc brake systems, built from blue-anodized aluminum and supplied with 3/8-24 inverted flare fittings for quick installation.

This small, precision valve preserves a slight pressure in brake lines to keep wheel cylinders and calipers properly primed on disc-brake conversions or custom brake plumbing. Machined in the United States, the unit uses standard 1/8" NPT inlet and outlet ports and arrives ready to fit common domestic and performance brake lines. Lightweight and corrosion resistant, the anodized aluminum body is designed for durability in harsh under-hood or chassis locations.

How does this valve affect brake feel and pedal return?

The device holds roughly 2 pounds of residual pressure so fluid stays in the calipers without adding perceptible pedal stiffness. That small preload prevents air ingress and maintains caliper position, helping consistent pad contact when the system is otherwise at rest. It’s tuned to avoid compromising pedal travel while providing functional line pressurization.

• Set to about 2 lb spring pressure for minimal pedal feedback
• Helps keep caliper pistons seated and fluid-filled
• Designed not to interfere with normal hydraulic release

What fittings and port sizes are included for installation?

The valve features 1/8" NPT inlet and outlet ports and ships with matching 3/8-24 inverted flare fittings so you can connect to typical automotive brake lines without sourcing adapters. The included fittings convert the NPT ports to inverted flare hose ends commonly used on many performance and classic brake plumbing setups. That makes the unit adaptable to both stock and aftermarket lines.

• 1/8" NPT inlet and outlet ports on the valve body
• Included 3/8-24 inverted flare fittings for common brake hoses
• No additional adapters needed for standard inverted flare systems

Where should I mount the valve and will it withstand under-vehicle exposure?

Mount the valve on a rigid bracket or threaded boss in the engine bay or along the chassis brake line where it stays protected from direct debris impact. The anodized aluminum resists corrosion and heat, but it’s best placed away from extreme exhaust heat or heavy road spray. Install with thread sealant suitable for brake systems and secure the fittings to prevent vibration loosening.

• Intended for protected under-hood or chassis locations
• Blue anodize offers corrosion resistance and visual ID
• Lightweight construction reduces added mass on lines

Who is this for? This Wilwood residual pressure valve is aimed at vehicle owners, fabricators, and performance shops installing or upgrading disc brake systems who want a reliable low-pressure preload to maintain caliper readiness. It’s particularly useful for classic car restorations, custom brake plumbing on hot rods, or race-prepped street cars where consistent caliper position and prevention of line air are important. If you need a compact, US-made valve with standard ports and fittings for quick integration, this unit is designed to meet those needs.

Product highlights and specs at a glance: 2 lb residual pressure setting; 1/8" NPT inlet and outlet; included 3/8-24 inverted flare fittings; anodized aluminum body; package dimensions ~2.5 x 10.2 x 14 cm; package weight ~0.023 kg; made in the United States. Follow standard brake system installation and bleeding procedures when fitting this valve.