Which proportioning valve should I use??

-
stroker_valiant

stroker_valiant

Well-Known Member
Joined
May 26, 2009
Messages
496
Reaction score
5
Location
Tulsa Oklahoma
Which proportioning valve is the correct or safer way for a street car?
Option 1: factory style valve pictured below. It has two lines in, three out. This valve is off of a 79 Plymouth Volare, it was a disk /drum car, but I do not know if it was a power or manual car.

Option 2: run the newer adjustable valve (the bottom picture) in line with the rear brakes only. The concept I believe to work would be run the front brakes with no valve whatsoever, just a T union to split the lines to the left and right, and turn the pressure down on the rear line until the rear brakes stop locking under hard braking.

I am not sure which setup will be the most effective and safest. I hear others saying I need the factory valve because is has an internal valve that give proportionate pressure to the rear, not always a set pressure like I would have in option 2. Any help would be appreciated. Or if somebody could direct me towards some literature on the matter, that would be good as well.
 

Attachments

  • IMAG0299 - Copy.jpg
    94.5 KB · Views: 1,521
  • wil-260-8419_cp.jpg
    10.5 KB · Views: 1,513
On my first setup I had the aftermarket valve you have pictured installed in the brake line between the master cylinder and the stock factory distribubution valve.
 
on my 68 barracuda, with a 73-up disc brake conversion, and rear drums, this is the prop valve that I used...

http://www.summitracing.com/parts/CLP-PV-2/

i drilled new mounting holes for it, and put it down here:

IMG_2180.jpg
 
This is the way I think I am leaning towards, could this setup be used with a line lock plumed inlint on the front brake line before the prop valve? Have your car been on the road with this setup??


mopardude318 said:
on my 68 barracuda, with a 73-up disc brake conversion, and rear drums, this is the prop valve that I used...

http://www.summitracing.com/parts/CLP-PV-2/

i drilled new mounting holes for it, and put it down here:

IMG_2180.jpg
Click to expand...
 
stroker_valiant said:
This is the way I think I am leaning towards, could this setup be used with a line lock plumed inlint on the front brake line before the prop valve? Have your car been on the road with this setup??
Click to expand...

I am not entirely sure about the line lock setup...I have used this current setup for a very short trip around the block. From just that little trip, It works great, I have good solid brake pedal, and the car stops nicely.
 
I don't see why a line lock would hurt before the prop. valve, it would be easier than putting it after the valve and having two lines to tie into it. I guess thats the trial and error part of it.
 
The line lock should be after the Proportion Valve. I know this from experience, it will not lock the front brakes and on burn out the car will roll forward.

This is the correct way to run your brake lines with a line lock and proportion valve.

1] disconnect both front brake lines from proportioning valve

2] install a pipe plug into one of the holes were either of the front brake lines was hooked up to

3] install/route a line from the remaining open port on the proportioning valve to the solenoid "in" on the line lock

4]install/route a line from the solenoid "out" of the line lock to a T-fitting "unless your Solenoid has 2 line outputs"

5] at the T-fitting "or solenoid that has 2 line outputs"-- install /tighten the two front brake lines
__________________
 
Plugging one of the two front output lines on the prop valve, that won’t cause problems running two brakes off of one port? I don’t think I would have thought of this route, interesting…


Mad Dart said:
The line lock should be after the Proportion Valve. I know this from experience, it will not lock the front brakes and on burn out the car will roll forward.

This is the correct way to run your brake lines with a line lock and proportion valve.

1] disconnect both front brake lines from proportioning valve

2] install a pipe plug into one of the holes were either of the front brake lines was hooked up to

3] install/route a line from the remaining open port on the proportioning valve to the solenoid "in" on the line lock

4]install/route a line from the solenoid "out" of the line lock to a T-fitting "unless your Solenoid has 2 line outputs"

5] at the T-fitting "or solenoid that has 2 line outputs"-- install /tighten the two front brake lines
__________________
Click to expand...
 
80% of stopping is front disk, dont know about drums. the prop valve has a spring loaded piston that takes a huge amount of pressure to push back and uncover the rear brake port. The front 2 outs are for the disk and they are just an internal T, nothing between them. I used one out of a disk/drum jeep and it worked fine. I dont think they are model specific,. maybe more like weight specific? Youll actually increase the tension on the prop valve if the rears lock up. you want the fronts to lock first. I dont think I would ever want the backs to lock and swing around.
Let me clarify something I just learned. The prop valve actually limits the pressure to the rear brakes when it exceeds a set internal pressure dependent on the spring loaded piston. When it exceeds this set pressure, ie. in a panic stop, a valve closes and limits pressure to the rear brakes. Sort of limiting the brake pressure to the rear in a panic stop.
 
You must log in or register to reply here.
-

Back
Top