1979-93 Mustang Wilwood Adjustable Proportioning Valve by Wilwood

1979-93 Mustang Wilwood Adjustable Proportioning Valve
1979-93 Mustang Wilwood Adjustable Proportioning Valve
1979-93 Mustang Wilwood Adjustable Proportioning Valve
1979-93 Mustang Wilwood Adjustable Proportioning Valve
How To: Fox Body Mustang 5 Lug Disc Conversion - SVE (1987-1993)

Get this fully adjustable brake proportioning valve from Wilwood to fine tune your braking system!

Item #WIL-26010922
MPN# 260-10922

Everyday Low Price: $48.44

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  • Allows Fluid Pressure Adjustment
  • No Adapters Needed
  • Easy Install


  • Forged Billet Design
  • Wilwood Engraved Logo
  • Fully Adjustable From 100-1,000 PSI

 What's in the Box

  • (1) Proportioning Valve

Wilwood Proportioning Valve
Now you can fine-tune your Mustang's brake system for the performance you need, whether at the track or drag strip! This proportioning valve weighs only 5.2 ounces and has two .25" side mounting holes spaced 1.00" apart. Unlike a standard knob-style valve, the in and out ports on this proportioning valve are 3/8-24 inverted flare seats, which do not require a tube nut adapter to install 3/8 tubing with inverted flare 3/8-24 nuts. With this valve from Wilwood, you can adjust the line pressure from 100-1,000 psi, depending on your preference.

Not OEM Replacement

Adjustable proportioning valves are designed to tune and balance custom brake systems on performance, racing, and other special-purpose vehicles. They are not designed as direct replacements for any OEM application.


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  • Ford Mustang - 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993
Fitment Notice
  • Installation: Proportioning valves are normally installed in the rear fluid line to prevent the rear wheels from locking before the front wheels or to give a driver the ability to make fine adjustments in front-to-rear bias percentage on the track to compensate for tire wear, fuel load burn-off, or changing track conditions. It is generally not recommended to attempt to reduce front wheel braking capacity. Use only the two .25" body holes to secure the valve to a mount. Do not attempt to remove the adjuster knob or valve body end cap to facilitate thru-panel mounting.
  • Adjusting: The adjusting knob is marked with an arrow indicating the direction required to decrease line pressure to the calipers. The knob rotated all the way out (counter-clockwise) will provide a maximum pressure reduction of 57%. Rotating the knob (clockwise) will incrementally increase line pressure up to full pressure. If the valve adjustment range is insufficient to balance the vehicle’s bias properly, changes to other components within the system may be necessary.
  • Testing: Do not attempt to operate the vehicle until the system has been fully tested under controlled conditions in a safe location. After the system has been bled, checked for leaks, and the proper pedal resistance and travel have been determined, make a series of low-speed stops, then gradually progress to normal operating speeds.
  • Warning: It is the responsibility of the person installing any brake component or kit to determine the suitability of the component or kit for that particular application. If you are unsure how to use this brake component or kit safely, you should not install or use it. Do not assume anything. Improperly installed or maintained brakes are dangerous. If you are not sure, get help or return the product. You may obtain additional information and technical support by calling at (254) 296-6500 or visiting our website at The use of technical support does not guarantee proper installation. You, or the person who does the installation, must know how to use this product properly. It is impossible over the phone to understand or foresee all the issues that might arise in your installation. Racing equipment and brakes must be maintained and checked regularly for fatigue, damage, and wear.
  • Proper bleeding of the entire brake system is required upon installation.

How To: Fox Body Mustang 5 Lug Disc Conversion - SVE (1987-1993)

Check out our YouTube channel for even more tech tips, installation videos, how-tos, and more. The best place to go for anything Mustang related!

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About This Brand

Wilwood engineering has desinged and manufactures high performance disc brake systems since the late 1970s. Their extensive research has led to the ability to quickly manufacture brake components for nearly every application. Providing Mustang owners with big brake kits and performance brake components, Wilwood has set the industry standard when it comes to quality products. Their six piston calipers, drilled and slotted 2 piece rotors, and many other parts make up big brake kits designed to get your brake system performing at its best. Get your Wilwood Mustang parts at!
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