Proportioning Valve Set Up

[TANG30]

Hello

My question is...... are all set ups the same. My valve seems to be turned all the way in ( clockwise ), To me this means it is equal pressure all the way around. How is the best way to set them so the fronts are locking up first ? Thanks for any advice.

[shaune]

When i did the disc brake set up in my 59 F100 the instructions on the prop valve stated something about driving on a graveled road and firmly applying the brakes. Adjust the valve in or out until the front are just on the verge of skidding and the back are still rolling. I think the front are to "lock up" before the back.....if I'm wrong someone will corect me :D
Anyway something about a gravel road and nailing the binders.

[1Bad56]

In a disc/drum set up, the front is set at 2 lbs. and the rears at 10 lbs.
More pressure is required to the initiate the drums than the discs.

[TinyTin]

the valves mentioned as 10lb and 2lb are residual valves that keep pressure in the lines and cylinders to help quick brake application. The proportioning valve sets the pressure to the rear brakes. The valve I have turns out to drop the pressure to give more braking on the front. The front tire should skid just before the rear does, my car has about 75% front-25% rear. Hope this is some help.
Don

[d.w.]

Whatever way yours is - out for more front pressure or in for more front pressure - it would be good to test the difference between in and out. Wind it all the way in, go fast enough that when you brake aggressively, you'd expect the brakes to lock up. Have someone stand off to the side so they can see your wheels, and keep testing it, changing the proportioning valve in increments until you find the right setting (where the fronts lock up first).

You also might want to double check and see if your valve is diectional and that it's installed correctly.

[Rochie]

Andy,
Tin is right about the residual valves, and both he and DW are right about testing the brakes until they "Feel" right and the front slides first.
Tiny tin, I don't know if I would leave the ratio at 75/25. Personally, I would rather see 65/35 or 70/30, BUT... and there's that but again, I haven't driven your car, I don't know the friction differential front to rear(i.e., Bigs an' Littles?). I do know that with the 65/35 or 70/30 you would probably go through two sets of front pads to one set of rear shoes, which is right where the mfg. are and end up with a more balanced system.

[TinyTin]

Rochie, I use this setup because of tire size. I should have explained the need to take this into consideration for each persons setup.
Don