Proportioning Valve

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moparstud440

moparstud440

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I recently switched my car (69 cuda) from front drums to disc. I bleed the lines, but still might have some air in the lines, but not positive. My pedal still feels a little on the "weak" side. I still have the factory Distribution block. I know I should change it out for a proportioning valve, but would that make the pedal feel soft? Also where is a good place to get a proportioning valve that will mount in the distribution block location?
 
power or manual brakes?
did you mount the calipers to the front or rear of the spindles? anyhow make sure the bleeders are on top otherwise you will never
get all the air out.
 
The distro block will NOT make the brakes soft. make sure the bleeders are on the high side. Make sure the rear shoes are adjusted

My own car (still apart) is Ford Versailles rear disk +Duster front disk. I left the old drum master in (67) and the old distro block. They are manual, and the pedal is hard as a rock
 
Manual brakes. Rear mounted the calipers, but bleeders are at the top. I adjusted the back brakes. I didn't bench bleed master cylinder so I think I still have an air pocket trapped in there yet.
 
moparstud440 said:
I recently switched my car (69 cuda) from front drums to disc. I bleed the lines, but still might have some air in the lines, but not positive. My pedal still feels a little on the "weak" side. I still have the factory Distribution block. I know I should change it out for a proportioning valve, but would that make the pedal feel soft? Also where is a good place to get a proportioning valve that will mount in the distribution block location?
Click to expand...
Questions:

Are you using a disc master cylinder?
Did you swap the brake push rod to the correct length?

Either one of those could give you a soft pedal.
 
A drum brake master will not cause a soft pedal. A drum master has residual valves in each outlet, as opposed to a disk master which only has the residual valve in the drum outlet. A residual valve will "hold out" the pistons a bit causing them to drag. You can easily defeat them by simply running a nail in through the valve rubber with the fitting disconnected. To actually remove them, you need a very small sheet metal screw which will screw into the brass seat, then yank it out with a claw hammer and remove the valve rubber and spring.
 
I swapped the master cylinder for disc/drum setup. I used the brake rod that was in the car..is a disc/drum rod longer than a drum/drum?
 
moparstud440 said:
I swapped the master cylinder for disc/drum setup. I used the brake rod that was in the car..is a disc/drum rod longer than a drum/drum?
Click to expand...
there is differences, yes
 
67Dart273 said:
own car (still apart) is Ford Versailles rear disk
Click to expand...
Post hijack.... 67dart273, do you need an adjuster tool for your Ford rear discs?, I might still have one from the 80s when I put the same on a 56 F100

Hijack over
 
moparstud440 said:
Manual brakes. Rear mounted the calipers, but bleeders are at the top. I adjusted the back brakes. I didn't bench bleed master cylinder so I think I still have an air pocket trapped in there yet.
Click to expand...
I have manual front disc on my 67 Barracuda.
Never got a good pedal until I borrowed a power bleeder and power bleed the front and rear.
Night and day difference.
 
I would start with bench bleeding the master cylinder then bleed your lines again. You will never get pressure without bench bleeding the master cylinder. Iv made that mistake once!
 
A soft pedal can be either or both, a hydraulic, or a mechanical, issue.

As to bench bleeding;
The reason we remove the MC to the bench, is so you can angle the front down, so that the air will come UP to the compensating ports, and exit into the reservoirs, when you tickle the pistons; AND so you can install those little short hoses to return exiting fluid back into the reservoirs; firstly so it doesn't make a mess, and secondly, so the MC doesn't suck air in from the discharge ports.
Yes, you can angle the front up, it only takes more pumps to purge the air out the other end.
So;
It is possible to "bench bleed" it on the car. But it's probably just as messy,lol.
 
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Bench bleeding on the car is easy just bend up a couple short lines with the correct fittings. Bend the
lines so the ends are down in the fluid at all times
then slowly pump the pedal
 
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