proportioning valve setting? help please

[65notch]

i just completed the granda swap front brake swap. and i installed an adjustable prop. valve for the rear drums but im lost on how to adjust it correctly? can anybody share with me how to do this..thanks guys
-jeff

 

[65 fastback]

I set my prop valve by taking my car out on either a dirt road or right after a rain. Do several hard stops from around 30 mph. You should be able to tell if the fronts or rears lock up first - adjust your prop valve accordingly. Once you get the brake bias dialed in, back out the rears just a little. Ideally you want the fronts to lock up first in the event of a panic stop.

Tim

 

[red65]

I set my prop valve by taking my car out on either a dirt road or right after a rain. Do several hard stops from around 30 mph. You should be able to tell if the fronts or rears lock up first - adjust your prop valve accordingly. Once you get the brake bias dialed in, back out the rears just a little. Ideally you want the fronts to lock up first in the event of a panic stop.

Tim

What he said, but I think you should be doing it on dry pavement, and a little slower (maybe 15-20mph). On dry pavement, you can be pretty sure that the front and rear wheels have similar friction with the pavement, while that may or may not be true on a dirt road or in the rain. Go slow, and be careful. Best bet is to have a friend (outside the car) tell you which wheels lock up first. It's possible to do it yourself (ask me how I know), but I'm not sure it's wise.

Do a hard stop, note which wheels lock, and adjust your prop valve. Adjust it until the front wheels lock just a fraction of a second before the rear wheels. It'll take a few tries to get it right - be patient.

 

[TOM B]

So the prop. valve should be connected to the REAR drum brakes?
I thought it was connected to the front disc brakes

 

[dennis112]

So the prop. valve should be connected to the REAR drum brakes?
I thought it was connected to the front disc brakes

Nope, it is connected to the rear drum brakes.

 

[TOM B]

O *****, I bought a prop valve and In the instuctions they had a drawing with the prop in the front lines. No wander I never felt a difference in braking.
Well the engine is out for cleaning so I might as well change that also.

 

[downpiped]

I just did my granada front swap...didnt use the prop. valve...everything is fine...no lockups...except for my fronts on a hard brake slam...my rear drums must be shot...but I will put the prop. valve on when I swap my versailles rear end in...

 

[SoCalCruising]

I have always, until this thread, heard that the rears should lock up first. Just recently, I was reviewing a front disc/rear drum article and they said (the Baer rep said) that the rears should lock up the last few feet of a panic stop. True, these were 60-0 mph stops, but I would think that this would translate to slower speeds, too. What gives?

 

[blue65coupe]

If the rears lock up first it will send you into a tail spin. PV in the rear lines. However, I have done this same swap and adj. the pv and the rears never lock. Actually, the fronts won't either. PV to the rears with the fronts locking first then the rears.