65 Barracuda disc swap…. Question on the distribution block

[Blue62Val]

Hi guys.
Didn’t post in brakes because I’m after people who know the early stuff.
I’ve got some Aussie PBR calipers etc to convert my Formula S drums to disc.
I am waiting on a dual master cylinder 15/16 bore (for disc/drum), a NOT going boosted, but have a question on the junction box.

Do I need an actual proportioned valve metering block, OR…… will a simple line splitter suffice ?

I’m wondering does the rear drum section of the MC regulate pressure to the rear, or do I actually need a proportioned style block ( or a remote in line proportioned vale ) to the rear.

I just want to make sure I get the right one.

Thanks,

Peter

 

[66Valiant528]

You can do full master pressure to the front disc and should use an adjustable valve for the rear drums. Im sure who ever valve you use will have adjustment instructions.

 

[Professor Fate]

I’m wondering does the rear drum section of the MC regulate pressure to the rear, or do I actually need a proportioned style block ( or a remote in line proportioned vale ) to the rear.

The front MC reservoir feeds the rear brakes, the rear reservoir feeds the front brakes.

Do I need an actual proportioned valve metering block, OR…… will a simple line splitter suffice ?

A "simple line splitter" alone won't do it.
Best way is to use a factory-type proportioning valve and mimic the later disc brake line routing for the MC you're using.
However (and read this carefully), you can plumb the rear reservoir directly to a splitter that feeds the lines to the front discs, and plumb the front reservoir into an adjustable inline proportioning valve and then to the rear brakes.
You MUST use a prop valve of some sort to regulate pressure to the rear, or the drums will lock up first and cause a spin.

 

[Dana67Dart]

If you have regulations on aftermarket parts, all the OEM parts are available and the use of them even if from a different year might draw less attention

 

[4mulas]

You’ll need a proportioning valve. I recommend an inline adjustable one on the rear line.

 

[cudamark]

I just use the factory '67-72 prop valve on my '66's, along with the hard lines. You just need an adaptor fitting for the rear brake line.

 

[Blue62Val]

Guys, thanks very much.

That’s exactly what I was after. Looking at the valves/splitters, I wasn’t certain why they’d make some without a proportioner built in, but obviously it’s because people add an inline vale on the rear brake line.

And I assume I simply don’t worry about the warning light switch on the “built in” ones ?

 

[Blue62Val]

I just use the factory '67-72 prop valve on my '66's, along with the hard lines. You just need an adaptor fitting for the rear brake line.

Do you mean just plumbing so the valve can be installed somewhere along the line ?

 

[Dana67Dart]

There are 3 basic setups (OEM) 67 up.

Drum / drum. Used a distro block with a brake safety switch.

67 -68 disk drum used the drum / drum distro block and an add on rear brake line proportioning valve.

1. 69 up disk / drum combo valve - distro block/ brake safety / proportioning valve in one.

 

[slantsixdan]

Do I need an actual proportioned valve metering block,

Yes.

will a simple line splitter suffice ?

No.

does the rear drum section of the MC regulate pressure to the rear

No.

 

[cudamark]

Do you mean just plumbing so the valve can be installed somewhere along the line ?

On my '66, the rear line wouldn't just plug into the later valve without a fitting to adapt it. Different size fitting.

 

[JDMopar]

I'm adding disc brakes to my 65 Barracuda too. I will be using the 69 and up valve that Dana posted above. The line that comes from the largest reservoir on the master cylinder plumbs into the top fitting. The 2 lines feeding the discs plumb out of the 2 ports right underneath that. The line from the smaller master cylinder reservoir goes into the port right under the brake light switch, and the port towards the rear is where the line going to the rear brakes plumbs out and goes all the way to the rubber line at the rear differential.

 

[Blue62Val]

my '66, the rear line wouldn't just plug into the later valve without a fitting to adapt it. Different size fitting.

On my '66, the rear line wouldn't just plug into the later valve without a fitting to adapt it. Different size fitting.

Just to make sure I don't stuff up....... my disc / drum master cylinder arrived yesterday.

I can use the same pushrod ?? Or do I need a different one ??
I've attached a pic of what I currently have.

 

[66Valiant528]

I used the single pot pushrod on the wife's 64 when I did a split system.

 

[Two Time Signet]

Just to make sure I don't stuff up....... my disc / drum master cylinder arrived yesterday.

I can use the same pushrod ?? Or do I need a different one ??
I've attached a pic of what I currently have.

View attachment 1716496339

View attachment 1716496340

I'm doing the same shortly and others confirm the manual 66 pushrod will work with later dual cylinder with disc brakes. master cylinder pushrod interchange

Let us know how it goes and congrats on the upgrade.

 

[Blue62Val]

I'm doing the same shortly and others confirm the manual 66 pushrod will work with later dual cylinder with disc brakes. master cylinder pushrod interchange

Let us know how it goes and congrats on the upgrade.

Thanks mate.
I've ordered the 69 up distribution valve - just waiting on that. Aussie PBR rotors and calipers, been in the shed for years.

I was going to keep the drums, but honestly - it's just better braking with discs.