Wilwood Adjustable Proportioning Valve for Brake Bias — Silver Forged-Billet, 100–1000 PSI Fine-Thread Knob

Wilwood 260-8419 is a compact forged-billet adjustable proportioning valve with a precision knurled knob that meters rear brake line pressure from 100 to 1000 PSI. This compact unit modernizes classic brake bias control by combining a lightweight forged-billet body with fine-thread adjustability to let you tune front-to-rear braking balance. The valve accepts standard 1/8-27 NPT ports and ships with two adapter fittings to interface with common domestic 3/16" hard brake lines, making it a practical swap-in for performance streetcars, track machines, and custom brake systems.

How precise is the pressure adjustment on this valve?

The 260-8419 offers a wide, predictable range of metering from roughly 100 up to 1000 PSI, and its fine-thread adjuster knob allows incremental tuning so you can dial in brake bias without abrupt changes. The design permits up to a 57% reduction in rear line pressure at full adjustment, which is larger than most comparable units.

• Adjustment span: approximately 100–1000 PSI
• Maximum proportional reduction: up to 57% of line pressure
• Fine-thread knob for small, repeatable changes

What are the physical and mounting details I need to know?

The valve is engineered as a lightweight, durable billet assembly weighing about 5.2 ounces, ideal where low mass and strength matter. It includes two .25" side mounting holes set 1.00" apart for compact mounting locations and standard 1/8-27 NPT inlet/outlet threads.

• Weight: ~5.2 ounces (lightweight)
• Mounting: two 0.25" side holes spaced 1.00" apart
• Ports: 1/8-27 NPT inlet and outlet

Will it connect to my existing brake lines and fittings?

Yes — the valve ships with two 1/8-27 NPT to 3/8-24 inverted flare female adapters, which fit most domestic 3/16" hard brake lines and common fittings used in aftermarket and OEM systems. That makes installation straightforward in many builds; adapters let you avoid custom tubing in most cases.

• Included fittings: two 1/8-27 NPT to 3/8-24 inverted flare female adapters
• Compatibility: suited for most domestic 3/16" hard brake lines
• Thread type: standard NPT inlet/outlet for broad fitment

How does the knob and build quality affect long-term use?

The machined adjuster knob uses fine threads for repeatable, vibration-resistant settings and a tactile feel for precise bias changes. The forged billet construction resists deformation under clamp loads and heat, providing consistent operation across seasons and track sessions.

• Construction: forged billet for strength and stability
• Adjuster: fine-thread knob for reliable, repeatable settings
• Serviceability: standard fittings and ports simplify replacement or rework

Who is this for? This Wilwood proportioning valve is built for drivers and technicians who need compact, accurate brake bias control without heavy plumbing or complex electronics. It suits performance street vehicles, race cars, and custom builds where weight, space, and precise manual adjustment matter. If you want an easy-to-install, high-range metering valve with durable machined construction and common fittings included, the 260-8419 is designed for that role.

FAQ

Q: What pressure range does this Wilwood proportioning valve cover?

A: The valve meters pressure from roughly 100 to 1000 PSI, allowing up to a 57% decrease in rear line pressure.

Q: Are fittings included for standard brake lines?

A: Yes, it includes two 1/8-27 NPT to 3/8-24 inverted flare female fittings for most domestic 3/16" hard lines.