dual master cylinder

Hello,

I am working on a new project and using (late 1940s) Ford juice brakes. A couple of my friends recommended a dual cylinder instead of a single. Which would be the best for late 1940s Ford brakes? What size bore would be the best? One of my friends commended a 1967 mustang master cylinder.

Could use some help.

Thanks,
Marty

 

The Mustang unit is a 1" bore and works well with the Ford brakes. Speedway sells one with a stainless sleeve which is a great upgrade PN 910-31425. Make sure if you get one from NAPA or something that there is no residual valve in the front bore. Easy to pull if they are. It will drive you nuts if you don't. The Speedway one comes without one.

 

Would the dual master be one unit for the clutch and brake?

 

"Now yer talkin' "

but I know they are talking about the dual safety brake cylinder...not the old hot rod deal.

 

Vintage drums brakes need residual valves, and '67-early '70s Mustang (and other) drum/drum masters had one located internally behind each tube seat. The problem now is most new or rebuilt replacement drum/drum masters do not have the valves installed, requiring the installation of aftermarket 10 lb valves going to each axle. Always check the drum/drum or disc/drum master you are using for internal factory-type residuals.

 

Thanks for the help. I found a number of posts that were helpful as well. I know what to look for.

Marty

 

single masters are fine.. untill something leaks, then it can get scary in a heartbeat... nothing like going to hit the brakes and the pedal goes to the floor and the car doesn't stop.. dual pots are way safer.. that is one of the regulations that nader actually got right...

 

I used late model Corrvette on mine works good

 

Depending on peddle ratio (at least 6 to one) non power. 1 1/8" max 1" min. And 10 lb valve's in front and back.
I too also used a corvette MC.
Good luck on the project.

 

V8BOB, I mentioned the internal residual valve because I've had more than one instance when the internal valve made the front brakes impossible to bleed. Not always, but I've become accustomed to checking that if somebody can't get a set to bleed up. I have no idea why. The extra valve should be redundant.

I ***umed anybody working on a brake system should know enough to put the 10 lb. valves in line. These obviously overcome spring pressure and keep fluid from draining back to the MC when the MC is lower than the wheel cylinders, a problem not common on stock Fords.

There's a lot to a brake system and I should have noted that in my reply. I'm glad you brought that up.

 

Interesting stuff. The info on the springs and such was given to me years ago, probably early seventies, by one of the bigger rod shops, I believe TCI. I've always thought it to be true. Your info makes sense. I agree the redundant valve should have no effect on bleeding, but I have had that condition in the past, which recently included the grey 35' pickup I built last year. I couldn't get the front brakes to bleed up. I checked on the MC, which came from TCI, and it did indeed have the factory valve in. After removing it, they bled up just fine. No idea why.

One thing I don't have a lot of experience with is early Ford single cylinders. Do they have a residual valve? I didn't think so.

 

Yes, the early Ford as well as other single (and later '67-mid '70s dual drum and disc/drum) master cylinders had some type of restriction or check valve to slow down and/or check a low psi of fluid returning to the master from the drum brakes.
There is one large brake component supplier that has a web site with a lot of useful looking information, but some is totally wrong, and residual valve operation is one. There is no way a 10-20 lb residual valve can come anywhere close to overcoming much more powerful shoe return springs. Drum brakes are designed to have the shoes return promptly to their anchors when the pedal is released, hence the strong return springs, and ...the need for a check valve to keep air from entering the wheel cylinders.
Improvements in wheel cylinder cups, like expanders, and front disc brakes becoming the standard, made residuals totally obsolete by the mid '70s.

 

There is a local here named ***us that makes them.

 

1" mustang would work. Some Torino M/Cs have the brake line ports on the opposite side of a mustang. May or may not make it easier to plumb.