Add-on brake proportioning valve

GoblinGuyZ

Well-Known Member
Anyone have a link to the exact 12" premade lines? Just want to make sure I get the right ones. Have the valve already thanks
 

Chubbs

Well-Known Member
Anyone have a link to the exact 12" premade lines? Just want to make sure I get the right ones. Have the valve already thanks

Added a proportioning valve. Like many I did not wish to purchase a bubble flare tool for a single use and could not locate one for rental or to borrow. Purchased a 12 in line (CNE-312) and bent the existing line and new line as shown. Valve is hidden but adjustable without raising the hood and the plumbing was only 6 bucks.
That CNE-312 is the one I bought. They had one at my local Advance auto store
 

GoblinGuyZ

Well-Known Member
I actually have mine turned pretty much all the way down in favor of the rear and can still get the front to lock up first but only now am I seeing the rear discs actually being worn.
 

GoblinGuyZ

Well-Known Member
Under panic, the fronts should lock before the rears - if the wheels do lock up. Better to slide the front than swap ends with the rear of the car in almost every situation.
Correct. I was trying to get the back to lock up first to find the limit and then dial back but even all the way down I'm still locking up front first so just gonna leave it that way. Brakes on a dime anyway
 

Ross

Goblin Guru
The proportioning valve has a limit... I think it is 57 percent maximum pressure reduction, if I got the specs to the correct Wilwood brake proportioning valve.
 

Rttoys

Goblin Guru
I’m now about 2 turns from max. It seems like the spring or whatever is inside is getting a little weaker. I have had to adjust it a couple of times in the last couple of years. Still works well though. A must have.
 

SmsDetroit

Goblin Guru
Okay dumb question. My proportion valve is mounted under my hood. I need to back off some on the rear brakes because they are locking up a touch before the fronts. Before I have to get in and out a bunch of times does anyone know which way to turn it to lessen the rear brakes?
 

GoblinGuyZ

Well-Known Member
Okay dumb question. My proportion valve is mounted under my hood. I need to back off some on the rear brakes because they are locking up a touch before the fronts. Before I have to get in and out a bunch of times does anyone know which way to turn it to lessen the rear brakes?
Clockwise or to the right to get more front brakes. Counterclockwise for more rear.
 

Jareth

Goblin Guru
Would this be the appropriate method of adjusting?

ADJUSTMENT PROCEDURE
  • Screw the adjustment knob completely out (Counter Clockwise).
  • Accelerate to approximately 30 MPH, then apply the brakes hard enough to lock up the wheels.
  • Have your friend watch (from a safe distance) and confirm that the front and rear wheels lock.
  • If only the front locked, adjust the knob in two full turns to allow more pressure to the rear brakes and test again.
  • Continue adjusting the knob in two turns at a time until the front and rear wheels lock in a hard stopping condition.
  • Adjust the knob out one complete turn and test this procedure again.
  • Continue these adjustments 1/4 to 1/2 turn in or out at a time until maximum braking can be achieved and no wheel rear lock is observed.
  • Test the vehicle again at 50 MPH to judge the effects of a more dramatic weight transfer and make any additional adjustments as needed. Typically this is achieved by turning the knob out to decrease pressure to the rear brakes.
TECH NOTE: When bleeding your brakes, it can be helpful to turn the proportioning valve all the way in to make bleeding easier. Make a note of how many rotations it takes to fully in, then adjust back out the same amount when finished with bleeding.

.
 

Chubbs

Well-Known Member
Close, but I think you have the way the valve works backwards.

Rotating the knob clockwise (right) increases flow (more brakes) to whatever brake you have the valve applied to. Counterclockwise (left) decreases flow (less brakes). It is opposite of any valve you've ever tried before. It's not a plumbing valve. It technically isn't regulating flow either, that's an oversimplification. There's a whole write up about it on the wilwood website if you're curious.

So assuming you applied the valve to your front brakes, turning the knob all the way left will almost certainly lock the rears first. It's a pretty dangerous situation, as it makes the car terribly unstable under braking.

I ended up turning mine all the way left, then turning it back right about two turns. That made the car relatively balanced. Unfortunately, you can only get it perfect on one particular day. Temperature variations in tires, and different friction coefficients on various surfaces (especially wet), will result in less weight transfer to the front and easier locking of the rear wheels. So, I would err on the side of caution. Once you found the "perfect" balance, I would turn the valve to the right another half turn to ensure that the front brakes always lock before the rears.

Lock the rears at your own peril.
 

mike_sno

Goblin Guru
I noticed that my front driver side tire is locking up first. Is there a way to adjust the front bias driver vs passenger side?
 
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