BeastMachine67

Does anybody know if the distribution block on the brake system is different a 67 mustang that came with all drums vs. one that came with disc and drums??

67t5ponycoupe

Disc/drum is different than drum/drum.

2+2GT

Yes, they are different. The disc version is available in repro.

67t5ponycoupe

I believe that the drum side holds some resisual pressure in the line where the disc side doesn't. If you held pressure on the disc side the pads would drag.

BeastMachine67

ha!!! I knew it!!! damn...why didn't that cross my mind earlier?? Check this out. I bought a 67 mustang last year and I've been working on it ever since. It orginally came with manual brakes but, it had disc brakes in the front and drums in the back. My buddy looked up the vin for me it turns out the car was orginally a drum/drum car. But ever since I installed power brakes on it, the brakes seem to stick now. as I'm driving it I have to sometimes reach my foot under the pedal to bring it back up after braking. It didn't do that before the conversion but, as many of you may know manual brakes suck!!
Anyways, I don't think the dist. block was ever changed and maybe this is the reason why my brakes are sticking. There's got to be some resid. pressure for drums and if that car had it.

Starfury

Not the problem at all.

The disc/drum block is a combo distribution block and proportioning valve, to reduce pressure to the rear brakes. Drum brakes require less pressure to operate than discs, so you need some sort of proportioning valve.

A power brake pedal sticking to the floor could be caused by a bad vacuum check valve at the booster.

2+2GT

No, that's a function of the master cylinder.

2+2GT

Depends what parts were used for the conversion. The OEM 67-69 disc brakes had separate divider block and proportioning valve, while the 70 and later were integrated. Be careful, the 67-up divider drum or disc incorporated a brake failure switch, incorrectly called a "proportioning valve" by many, many people.

If you have no true proportioning valve, your front brakes are doing very little, making your car unsafe.

JMD

Ideally disk will use 3 PSI residual, and drum will use 10 PSI.

I know there are some disk setups that use no RPV, but IMO 3 PSI works best for disk.

A 10 PSI RPV on disk will cause the disk pads to drag, causing hot brakes, and fast wear, and not to mention, a car that is hard to push...

If you have a 10 PSI RPV you will be able to tell by jacking a front wheeel off the ground and seeing if the drag is "reasonable:.

As mentioned, the problem with the pedal is probably something other than a RPV issue.

Does your car have a return spring? Might try that first.

BeastMachine67

I think your right, I used to have a 1969 mustang the setup on it was completely different. You would have your lines coming out of the mast cyl. into the dis. block and then you could actually see that the resid valve was sperate from the dis. block. But on the 67 its not setup that way. I think the resid. vavle is probably part of the dis.block