What Does a Proportioning Valve Do | Wilwood Brakes

Adjusting brake bias on your hot rod or muscle car with an adjustable brake proportioning valve can be confusing. Do you even need an adjustable brake proportioning valve? How to adjust a brake proportioning valve properly? Where should a brake proportioning valve be installed? These are all important questions that need solid answers.

To that end we visited with Mike Hamrick from Wilwood Disc Brakes to get these answers and provide you with peace of mind when plumbing your project’s brake system. Being able to adjust brake bias with a brake proportioning valve, such as a Wilwood adjustable proportioning valve, allows you to adjust the amount of rear brake in your vehicle, which is affected by such things as brake system type, tire size, wheel diameter, and more. Adjusting a Wilwood brake proportioning valve right on the car makes for quick changes to accommodate track conditions, tire compound changes, and more.

When considering your Wilwood proportioning valve install, it is best to install one during the brake system initial plumbing versus attempting to add one to the system later. You may not need a brake proportioning valve now, but the only way to allow adjusting brake bias will be with one later.

0:18 Is a brake proportioning valve necessary?
0:44 How does a proportioning valve work?
0:56 How to reset brake proportioning valve
1:56 How to adjust Wilwood proportioning valve
2:48 When do I need an adjustable proportioning valve?

[Dwigt_Rortugal]

So, if I understand correctly, normally turning any valve clockwise closes it, but with Wilwood valves, it's the opposite? The Wilwood rep said that all the way clockwise is wide open to the rear brakes. I'll watch it again.

[deankay]

Speedway you are the best! I think that pickups are worse as drums can lock and cause. You are changing one area from the proportioning valves hold-off pressure and the pressure point which effects the apply pressures. Keep the videos coming. DK, Omaha.

[thetxwildchild]

Nobody ever talks about what if you need more break to the rear... Will this give you more break versus a fixed proportioning valve?

[offgridmangogrower]

A general question about a master cylinder bore size range……without complicated formulas…..runnning a 6 pot and 4 pot calipers on a 3/4 t 56 travel-all…..?

[javierargumedo]

any idea how to wire proportioning valve switch? there is 2 wires.

[Buick]

so for drum drum 2 10lb checks for front and rear?

[GummyMann]

his instructions on how to set the valve are backwards according to the willwood instructions

[craig]

You can oil your rear drums up too, that will prevent them from locking up.

[linovassallo]

Hi. I have a set of Wilwood Disc Brakes. And a Proportioning valve installed. I am confused of how far do I have to screw in the valve. Shall I Unscrew it all out or Half-Way please? Thanks in Advance.

[Macnificent_]

What would be a good adjustment im running full wilwood brake system full qa1 level 2 Ford 9inch with 3.0 gears on a 26 inch wheel im trying to do a simple burn out an the car want to keep going Whats your idea setting for the Proportion val also I have a 383 stroker paired with a th350 any tip or trick would be greatly appreciated

[Archangel]

What if you have a pedal box with bias bar and dual masters? Would this still be an added benefit for further adjustment?

[linovassallo]

Just wanted to add that this is on a Ford Mustang 1970 Mach 1