Going to dual port master cylinder from a single port

[GJCAT427]

Okay I`m changing to a dual port master from a single port, question is what do you use as a juction block to split the lines? Or just run to the front direct from the master and the same to the rear? I`ve looked at a pressure differental blocks that lets you use a brake light warning unit if you loose the pressure in one or the other lines. But they all call for disc/drums. I`m staying with drum/drums. Scott Drake has one , but lists it as disc/drum. And I`m working on 1/4" lines and most are for 3/16" lines.

[cjshaker]

On my '65 I ran straight to the front and straight to the rear. The car seems to stop fine with no issues, but I haven't tried a panic stop to see if one locks up prematurely. An adjustable valve would take care of that easily, if it did.

[Diogenes]

When I switched my Galaxie over, I sourced a proportioning valve from a mid-late 70s chev pickup and plumbed it all up. I figured any fullsize rear drive application with somewhat comparable weight/mass would provide a good source. You should be able to do the same, just look for a drum/drum application (not so easy to find drum/drum in a boneyard these days though). Its made of iron, works fine and didn't cost me anything.

[chris401]

Okay I`m changing to a dual port master from a single port, question is what do you use as a juction block to split the lines? Or just run to the front direct from the master and the same to the rear? I`ve looked at a pressure differental blocks that lets you use a brake light warning unit if you loose the pressure in one or the other lines. But they all call for disc/drums. I`m staying with drum/drums. Scott Drake has one , but lists it as disc/drum. And I`m working on 1/4" lines and most are for 3/16" lines.

On the 67 pickups the difference between full drum and disc/drum was the proportion valve in the rear line. The distribution blocks are the same.

[TomP]

What sort of Ford uses 1/4" line?

 I am doing the opposite, the 62 Ranchero had a dual master and i'm replacing it with a 66 Mustang "jam jar" big single disc master and using four wheel discs.  I need a provision for a brake light switch and will use an adjustable proportioning valve in the rear line.

 I've long since abandoned the idea that a dual master is any safety advantage.

[chris401]

What sort of Ford uses 1/4" line?

 I am doing the opposite, the 62 Ranchero had a dual master and i'm replacing it with a 66 Mustang "jam jar" big single disc master and using four wheel discs.  I need a provision for a brake light switch and will use an adjustable proportioning valve in the rear line.

 I've long since abandoned the idea that a dual master is any safety advantage.

You'll notice the difference between single and dual pot if you have ever burst or ripped a line loose while in motion.

[machoneman]

What sort of Ford uses 1/4" line?

 I am doing the opposite, the 62 Ranchero had a dual master and i'm replacing it with a 66 Mustang "jam jar" big single disc master and using four wheel discs.  I need a provision for a brake light switch and will use an adjustable proportioning valve in the rear line.

 I've long since abandoned the idea that a dual master is any safety advantage.

You'll notice the difference between single and dual pot if you have ever burst or ripped a line loose while in motion.

Oh, yes, you'll know damned quick if one loses brake fluid for any reason! Scary, indeed!

[shady]

Well, I had a 2001 Ford Escape and my wife called me one day saying she didn't have brakes. I said that is impossible, you either have front or rear, did you pump it? yes, nothing she replied. She drove it home from work with the hand brake. Upon inspection i found a front hose broken. What I couldn't understand was how there was no pedal until I went to fill the dual master cylinder. The divider between the reservoirs has a slot down the middle so one drains into the other. So, so much for the safer theory.

[Rory428]

I recently retired from a mechanic at a Toyota dealership. Over the year, I had replaced rusted out rear brake lines on 4 Runners, and believe me, when one of those brake lines broke, the brake pedal went straight to the floor. The dual master cylinder theory seems logical, but much like "self adjusting" drum brakes, never seems to work as planned. If the dual master design worked as well as it was thought, it would have made bleeding the brakes more of a chore. When you bleed a caliper or wheel cylinder, do you not notice that the brake pedal goes to the floor?

[Jb427]

When i changed my 66 fairlane from drum's all round to disc brake front i use a holden hg manaro master (chose this because it is the same cast ones you all get in the USA for 66/67 fairlane but alloy) but i used a remote booster that i mounted under the front left hand side guard i also fitted adjustable proportioning valve for the rear lines. Ends up i did not need that brakes are great. I also used Australian falcon stubs and steering rod ends they have a bigger stub axle and bigger alloy caliper with 15" rims. Im also running a Mal Woods under dash clutch master cylinder I did see some one asking about that a month or 2 ago very happy with it too.

[TomP]

I have lost brakes three times and all were on dual master cylinders. Two were on vehicles converted from a single to a dual for supposed safety. (65 Falcon and 53 truck) One had a right front brake hose rub through,  one lost a caliper when the bracket spread the other lost a rear wheel cylinder. All three went right to the floor. One of them gave me enough chances to hit the brakes many times and try to pump the pedal. When it finally stopped the rear reservoir was completely full and the front empty.

[GJCAT427]

Okay, some of you have asked what Ford uses1/4" brake lines? Well I`m working on a 64 F350 dually, setting it up for towing my Galaxie and what ever else I own. The truck has power drum brakes and it`s a single pot master. I`ve changed out the master from a 70-72 F350 drum set up(thanks Doug Smith). I have all of the fittings gathered up to do the change over and will begin running lines this week if the weather holds. Right now its powered by a 292 Yblock and it is a real possibility an FE will wind up in there.