The Wilwood Adjustable Proportioning Valve is engineered for pressure adjustment that is smooth and repeatable, allowing fine tuning from full system pressure down to a maximum 57% reduction, making it ideal for dialing in rear brake bias on custom and high-performance builds.

Constructed from a forged billet aluminum body, the valve benefits from optimized grain flow forging that realigns the alloys grain structure for improved strength, tighter machining tolerances, and superior resistance to deflection under high pressure. Compared to traditional block-machined billet valves, the forged design achieves greater strength with less material, resulting in a lighter, smaller, and easier-to-mount valve.

Includes:

• (1) Wilwood Adjustable Proportioning Valve
• (2) 1/8"-27 NPT to 3/8"-24 inverted flare female brake line adapters

Specifications

• Manufacturer: Wilwood
• Valve Type: Adjustable Proportioning Valve
• Adjustment Range: 057% pressure reduction
• Effective Pressure Range: Approx. 1001,000+ PSI
• Material: Aluminum / Steel
• Finish: Clear Anodize
• Weight: 5.2 oz
• Inlet Port: 1/8"-27 NPT
• Outlet Port: 1/8-"27 NPT
• Mounting Holes: (2) 0.25" diameter
• Mounting Hole Spacing: 1.00" center-to-center

Fitment

• Compatible with disc and drum brake systems
• Designed for 3/16" hard brake lines (with included fittings)
• Suitable for street, off-road, drag racing, dirt track, and road race applications
• Compact body allows discreet or exposed mounting locations

Tech Insight

A proportioning valve is critical for balancing front-to-rear brake pressure, especially in vehicles with upgraded calipers, mixed brake setups, or altered weight distribution. Wilwoods forged billet design allows this valve to withstand extreme line pressures while maintaining precise control. With up to 57% pressure reduction, it offers more adjustment range than most competing valvesmaking it easier to prevent rear brake lockup without sacrificing overall stopping power.

Adjustment Styles

Knob Adjustable

Infinitely adjustable with fine-thread control

Turn fully clockwise for full pressure

Rotate counterclockwise to progressively reduce output pressure

Lever Adjustable

Six detented positions for quick, repeatable changes

Lever at 90 (high cam) delivers full pressure

Step back one click at a time to reduce pressure incrementally