Brake Conversion

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64_Barracuda

64_Barracuda

Virginia Beach VA
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Ok folks here are the results of the RAM MAN disk brake conversion on a 1964 Plymouth Barracuda. Car started out with Power Brakes 9 inch drums. 14 inch 5.5 rims

What you get in the kit is everything needs to complete the conversion. Everything is from a 76 Dodge Dart system (brand new)

Spindles (Doctor Diff upper control arm sleeves for small ball joint)
Rotors (Machined down for Small bolt pattern rims 5x4)
Calipers (slider style)
Hoses bearings etc.

So it all went fairly well, I kept my original master cylinder so all still looks stock (I did pick up a Kelsey-Hayes master with the extension on top, still thinking of using it or not)

Spindles get reversed so calipers are in front (still don't know why this is).

The Good, it does work. The Bad you need to grind down the caliper some and/or use spacers, I currently have been doing grinding and using 3/16 spacers.

I am currently not running a rear proportioning valve; Wayne the owner said drive it and see if you need it, so far its 50 50 rears always lock up first but you really got to mash the pedal. I may go back and put one in the future.

Master Cylinder, ok after months of research before mod here it is. The bore is the same for power and manual, disk or drum. Difference is a residual valve in the front spring for drum cars disk cars have it removed other than that no difference. There is some math to be done, so with the big calipers, the amount of movement helps residual pressure bleed of on the rears so right now I don't feel the need to have one, but once again in the future as I put miles on a may, currently I only have about 30 miles.

All in all it was a good conversion, however, Wayne did not tell me that I would have to grind and use spacers, and I told him the rim I was using, my car is all stock, just getting older and would like disk brakes. I did have a set of Mag Rims (14 x 6) that I may put back on to see if I need a spacer.

I would recommend this conversion to other folks, except do it yourself through a Junk Yard or here on the web forum there always seems to be someone selling the right parts. The only thing you will need to do is machine rotors as in 76 Darts were already 4.5 unless you are switching your entire car.
 

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mguner said:
Are the wheels the reason for the grinding?
Click to expand...

Oh sorry, yes, the slider caliper is pretty big. As it turns out, my 65 Signet which had a disk brake conversion before I got it, has sliders, but it is big bolt pattern with 15 inch rims, no issues.
 
You CANNOT use that master cylinder!!! NEED to use a duel chamber M/C for disc brakes!!! CANNOT stress this enough!!!! AND a proportioning valve.
 
64_Barracuda said:
Why do you think I can't use this master?
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Really? For one the disc brakes displace lots more fluid then the drum did. Second, you will not get correct pressure to all four corners. Your safety is paramount. PLEASE research more. :burnout:MT
 
Mopar Tim said:
Really? For one the disc brakes displace lots more fluid then the drum did. Second, you will not get correct pressure to all four corners. Your safety is paramount. PLEASE research more. :burnout:MT
Click to expand...

Once the brakes are bled there is no fluid to displace, except the very little the pad and shoes wear.

What was wrong with the factory having a single master? They did that for two years 65 and 66.

With the Kelsey-Hayes master extension it actually has more fluid than a two chamber.

I understand where you are coming from, but the factory did that as well even with big full size cars. Hydraulics are Hydraulics as long as there is no air in the system your compressing fluid not displacing it, the only time your displacing fluid when the pads get wore down. So by pressing on the brake pedal, your only moving fluid very little as long as your shoes are adjusted correctly and you watch for brake pad wear.

Next time your in your car have someone step on your pedal and watch your fluid, if it goes down considerably you have a problem somewhere, should move very little if any your just compressing what is in your chamber. Your pads never need servicing because as the pad wears down the calipers don't suck back in right? No they just sit right where they are. Now the shoes sure every six months they should be adjusted as they wear down because the springs pull them back in.

Brake fluid is a mystery to a lot of folks, everyone thinks you need the biggest master in the universe, untrue I mean what is all the fluid doing in there when you press the brakes? Nothing just sitting on top of the piston, once you depress the brakes the fluid doesn't go in there, only when you release the brakes does the fluid go into the piston, but if it does that means you have let fluid out somewhere else, sure a tiny bit I am sure fills in as pad and shoe wear, but over all not much.

Now granted, if I drove this car everyday I would probably check the fluid once a week maybe, but like I said thats how it was done in the 60's seemed to work pretty good then.

Sure the draw back is if you have a leak you have no brakes at all, that is a given risk.
 

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you're correct the disc pads only move about .005 but fluid would be displaced over time with pad/shoe wear..just check occasionally.
..The real danger is a leak anywhere will cause total brake failure.
..A dual chamber master will prevent a total loss and be safer.
 
A single master cylinder was stock for a 4 wheel drum system and will work. If you went to a different system like disc/drum a dual master cylinder is needed. If you went to 4 wheel discs, in theory a single could work. The reason to add front discs is to make it safer to drive, not more dangerous.

edit: A good friend of mine was driving his 64 Galaxy conv. when his single master failed and he got good and scrayed going through a intersection inexpertly. It was converted to a dual system after that and this was from a very OEM numbers matching type of guy.
 
Do what you want, its your life. There is NO factory disc setup utilizing a single piston MC. where did you find that MC? Why would you use that?
 
I found it, ford mustang used this Mc for disc brakes. Not me!
 
Mopar Tim said:
Do what you want, its your life. There is NO factory disc setup utilizing a single piston MC. where did you find that MC? Why would you use that?
Click to expand...

No factory set up for disk brakes? Sure just about every manufacture did at one point or another. Even the big Imperial in 64 used the same Master, just bigger pads...
 
amx364 said:
A single master cylinder was stock for a 4 wheel drum system and will work. If you went to a different system like disc/drum a dual master cylinder is needed. If you went to 4 wheel discs, in theory a single could work. The reason to add front discs is to make it safer to drive, not more dangerous. edit: A good friend of mine was driving his 64 Galaxy conv. when his single master failed and he got good and scrayed going through a intersection inexpertly. It was converted to a dual system after that and this was from a very OEM numbers matching type of guy.
Click to expand...

Plenty of dual masters with drum brakes, most Valiants and Darts with 10 inch drums from 67 on up.

Sure it will work with a single disk/drum once again that's how it came from the factory. This is how they built them, all the pony cars GTO, Nova, Tempest, Mustang, Barracuda....

Once again I am not saying it's the safest, that's not what this post started as
 
64_Barracuda said:
Once the brakes are bled there is no fluid to displace, except the very little the pad and shoes wear. What was wrong with the factory having a single master? They did that for two years 65 and 66. With the Kelsey-Hayes master extension it actually has more fluid than a two chamber. I understand where you are coming from, but the factory did that as well even with big full size cars. Hydraulics are Hydraulics as long as there is no air in the system your compressing fluid not displacing it, the only time your displacing fluid when the pads get wore down. So by pressing on the brake pedal, your only moving fluid very little as long as your shoes are adjusted correctly and you watch for brake pad wear. Next time your in your car have someone step on your pedal and watch your fluid, if it goes down considerably you have a problem somewhere, should move very little if any your just compressing what is in your chamber. Your pads never need servicing because as the pad wears down the calipers don't suck back in right? No they just sit right where they are. Now the shoes sure every six months they should be adjusted as they wear down because the springs pull them back in. Brake fluid is a mystery to a lot of folks, everyone thinks you need the biggest master in the universe, untrue I mean what is all the fluid doing in there when you press the brakes? Nothing just sitting on top of the piston, once you depress the brakes the fluid doesn't go in there, only when you release the brakes does the fluid go into the piston, but if it does that means you have let fluid out somewhere else, sure a tiny bit I am sure fills in as pad and shoe wear, but over all not much. Now granted, if I drove this car everyday I would probably check the fluid once a week maybe, but like I said thats how it was done in the 60's seemed to work pretty good then. Sure the draw back is if you have a leak you have no brakes at all, that is a given risk.
Click to expand...

Where did I get this? Right out of the 66 Dart and Barracuda service manual, most folks never knew the Kelsey-Hayes system came with the top reservoir they are pretty rare, Dan Gurney said the average Joe won't need it. It was designed for the SCCA rally cars, had to be a production item for them to race.
 
From what I have found, Imperials used drum all around till 1967. Then they used disc drum with duel master cylinder.
 
How much was the conversion? I didn't see any prices on his website? Thanks. Eric L
 
I also don't understand the reason behind flipping the spindles either. Did swap lower ball joints side for side also? Eric L
 
64
Of course you can use that M/C. It will operate exactly as you say.
But;
The safety factor is not just for you. We know you will be doing everything in your power to drive safe and not have to depend on a 50 year old design. But safety factor should also consider the schmucks of this world who do stupid dangerous stuff in your flightpath.
As long as you are diligent in your total system maintenance, you may well never get into trouble.
But why, being as intelligent as you are about brakes, and while the conversion to a dual system is so easy and economical, would you choose to carry on with the single piston system?
I too have suffered a system failure. I lost the front brake, on a 2-piston system. And little did I know that the rear system was so far out of adjustment and had so little power. When the pedal went to the floor, I frantically pumped the pedal, and managed to avoid potential death. I can't say I would have been so lucky with a single piston M/C.
I would never knowingly operate a car on a public street with a single-piston system.
Do as you wish. . There are lots of stupid or inconsiderate people in this world,willing to see you test your brakes. Try not to kill or maim any of them.
 
prorac1 said:
I also don't understand the reason behind flipping the spindles either. Did swap lower ball joints side for side also? Eric L
Click to expand...

Eric,
So total price was 1000. 600 for conversion and then 400 for the machining of rotors for center hub to accept small rim and then drilling rotors to 5x4. If you go 5x4 1/2 I think it would run much cheaper.

BUT! You can get every piece at the parts store except the spindle and caliper holder (I think that is it, not enough coffee yet) If you go 5x4 1/2 if you go 5x4 you may have to find a machine shop to bring the center hub down and pop your stud holes. And if you keep your upper arms small with the small bolt pattern you would need the upper control arm bushings.

Or you go kelsey-hayes need to find spindles, and hubs Rock Auto and Napa sells everything else except the brake hose holder, but Daves Cuda (member here) makes them.

In hindsight I am going to gather a Kelsey-Hayes and put it together in the spring just like the factory did. See how that goes..... the entire swap literally is like a few hours Upper ball joint lower ball joint tie rod and brake line and your out....... the bleeding, alignment that is the time part.....

OK your next question, no the upper ball joints stay there with the 76 Dart system you can do 1 of two things.
1) keep your stock upper control arm and get the Dr Diff bushings or;
2) Get the 72 and up upper control arm with the bigger ball joint and be done with it, but note you can never go back to 9 inch drums (not that anyone would not I suppose)

Your question on lower ball joints are right and left, your can't really swap them, the indent in the spindle is big enough for fitment.

I had just rebuilt my upper bushings so I got the ball joint bushing.

I still can figure out why the spindles get swapped, except 76 Darts are a few inches bigger than early A's Rick Eirhenburg says its because of hose movement. I dunno my 65 Signet has the same swap except it has big bolt pattern spindles are swapped and it has the factory hoses and they reach. This car also has a dual circuit master, but its a hot rod not a stock car.

Hope that helps.
 
AJ/FormS said:
64
Of course you can use that M/C. It will operate exactly as you say.
But;
The safety factor is not just for you. We know you will be doing everything in your power to drive safe and not have to depend on a 50 year old design. But safety factor should also consider the schmucks of this world who do stupid dangerous stuff in your flightpath.
As long as you are diligent in your total system maintenance, you may well never get into trouble.
But why, being as intelligent as you are about brakes, and while the conversion to a dual system is so easy and economical, would you choose to carry on with the single piston system?
I too have suffered a system failure. I lost the front brake, on a 2-piston system. And little did I know that the rear system was so far out of adjustment and had so little power. When the pedal went to the floor, I frantically pumped the pedal, and managed to avoid potential death. I can't say I would have been so lucky with a single piston M/C.
I would never knowingly operate a car on a public street with a single-piston system.
Do as you wish. . There are lots of stupid or inconsiderate people in this world,willing to see you test your brakes. Try not to kill or maim any of them.
Click to expand...

I keep the stock appearing system because it is a totally stock car, minus disk brakes and the radio that I converted over. It is the highest optioned car from 64, it was the Carlisle Nationals exhibit car in 2014.

Now my 65 Signet has the same brake conversion except it is big bolt pattern all the way around with a 8 3/4 rear and a dual circuit system, along with a 66 Barracuda interior and lot of other cool stuff, but its a hot rod, started out life as a /6 car.
 
The problem with the single reservoir master cylinder is that it is very dangerous. THe factories all realized this as cars were evolving and changed it. Yes, they work fine. Until they fail.

There is NO backup. Modern dual reservoir master cylinders are dual reservoir. In other words, they have two tanks to hold fluid. If there is a leak somewhere in the system, there is always a backup.

With the single reservoir master cylinder, a leak anywhere in the system results in pedal to the floor, and zero brakes.

None of the factories ever used the single reservoir master cylinder with disc brakes. Ever. Yes, it can be done. Yes. It works. But it is not safe.
 
RustyRatRod said:
The problem with the single reservoir master cylinder is that it is very dangerous. THe factories all realized this as cars were evolving and changed it. Yes, they work fine. Until they fail.

There is NO backup. Modern dual reservoir master cylinders are dual reservoir. In other words, they have two tanks to hold fluid. If there is a leak somewhere in the system, there is always a backup.

With the single reservoir master cylinder, a leak anywhere in the system results in pedal to the floor, and zero brakes.

None of the factories ever used the single reservoir master cylinder with disc brakes. Ever. Yes, it can be done. Yes. It works. But it is not safe.
Click to expand...

This... Single reservoir masters were outlawed by '66 ,federal law. Disc brakes need extra volume, hence the dual reservoir master cylinders: the large cylinder ,discs..,the small one : drums out back. Do it right here, it could be a life changing move, p.m. me if you want an answer.....
 
Pre 66 vehicles including mopars equipped with disk brakes absolutely did come from the factory with single master cylinders.
The 65 formula s disc brake equipped cars are just one example.

Safest set up. No , that's why it was changed in 66 .
For the sake of having an original look he is not sacrificing any more safety with this disk conversion than with driving with original single mc and drum brakes. I'm Sure the breaking feel and stopping distance has been improved with this conversion.


Oldschoolcuda
 

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I would like to see positive proof that the formuls s with FACTORY installed, not a dealer installed option, Disc brakes had a single res. MC. what I have seen is double or drum brakes on the 65 formula s cars.
 
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