63 Riviera Dual master conversion help.......

[Guest Kaber]

I started out wanting to add a Dual master Cyl. to my son's 1963 Riv. I have a brake block from a 1970 Chevelle with 4 wheel drum brakes and a new line kit for the Riv. I know there will be plumbing issues hooking up the M/C but was not expecting the Brake light switch on the M/C and not the brake pedal. Can I use the brake warning light port on the block from the Chevelle? Do I need to add a switch to the brake pedal? If I need to add a conventional switch to the brake pedal is there a recommended donor car from which to use the parts from? I am hoping someone here has done this before. I'm pretty clear on the mechanical part (M/C & Lines) but getting the brake lights to function was something I wasn't expecting. Any help or advice would be great! Thanks!

[RivNut]

If you have the port on the brake block from the Chevelle, the brake light switch should work; it just takes some hydraulic pressure to close the circuit. You'll probably have to splice the wiring to give some added length to the wires so they'll reach the new location. If you go with your other choice, you could look for the mechanical switch from a '64. Same basic layout, just different placement of the brake light switch. It's mechanical and operates in the conventional way off the brake pedal arm. If the '63 you have has cruise control, you may already have a solution.

There's a complete "how to" article written by Jim Cannon in the Tech Tips section on the ROA's website. It tells the step by step process and has measured drawings for brackets to hold the distribution block. Riviera Owners Assocation Home Page

Ed

Edited August 8, 2013 by RivNut (see edit history)

[Jim Cannon]

No. Sorry, Ed. I know what that block does on the Chevelle. It will not serve as a brake light switch port. There is no easy donor switch to add to the '63. the bracket is not there to mount the switch on.

Everything you need to know is in my write up. It is very easy to do with all stock parts, including the switch, except for the new line down from the MC and a few fittings.

I am happy to help after you read my article for the basics. That lets me avoid having to repeat myself.

[RivNut]

Oops, I guess that I'd better go back and re-read the article.

[Guest Kaber]

Thanks Guys! Jim, I have looked for your article on the ROA. I am not sure I have seen it. The one I found in the tech tips is by Bob Embry and kind of glosses over the brake light switch part?!?!? Tom sent me copies of the Riview articles pertaining to Dual master cylinders but the only thing by Jim Cannon was a short paragraph. If you can direct me as to where to find your article, Jim, it would really help me out. I am kind of leaning towards just rebuilding the existing system, the car stops well I'm looking at more of a saftey aspect of this conversion. I have a new line kit from inline tube but have purchased nothing else so far.

Thanks again for all your help!

[RivNut]

Jim's article is in the member's only section in the Technical Tips - brakes and suspension. It article #2 - Dual Master Cylinder Conversion for First Generation Riviera

If you're not an ROA member, it's not accessible to you. Just like American Express - Membership has its privileges.

[Guest Kaber]

I am a member, I just didn't see Jim's name associated with that particular article, and thought there might be a different one somewhere. The by line reads Bob Embry. Anyway, thanks at least I know I am looking in the right place.

After re-reading the article I am still unclear as to what has to be done to change from the pressure (HYD) switch to the more contemporay pedal operated switch. Also, Jim, does the Master cylinder from the 67 Riv work with either the Delco or Bendix brake system? Is an adjustable prop valve nessessary? Can I use the block (left over from a disc brake conversion I did last year)from the 4 wheel drum equipped Chevelle to direct the brake lines or is there an easier solution? (I realize that the brake lines won't match directly, I bought the NON-Stainless ones so it would be easier to form & flare) I know I may be making this harder that it really is, I am just trying to get as much information up front as possible.

Thanks!

[Guest Kaber]

Jim,

I found this on BUICKV8 and was wondering what you think....

I incorporated the factory pressure switch into the port on the distribution block where the rear line originally went. I used a female/female adapter (3/16 brake line fitting x 1/8" NPT) and a 12" section of brake line. This puts the switch right next to the master, and within range of the factory harness.

I thought it sounded logical. Remove the rear brake feed line from the factory tee on the frame. Add the above mentioned line and fitting to the existing tee to take care of the brake switch. Add a piece of line between the rear feed line to the master cylinder. Plumb the front M/C line to the tee just like the original set up.

If this all sounds right the only questions I have is will the 67 Riv dual M/C work with either booster? What is this about a seal between the M/C and Booster?

Thanks!

[RivNut]

I am a member, I just didn't see Jim's name associated with that particular article, and thought there might be a different one somewhere. The by line reads Bob Embry. Anyway, thanks at least I know I am looking in the right place.

Thanks!

I didn't realize that Jim did not write that article. He's done so much to help other with this project I guess I thought he was the guy who wrote it.

Ed

[steelman]

I incorporated the factory pressure switch into the port on the distribution block where the rear line originally went. I used a female/female adapter (3/16 brake line fitting x 1/8" NPT) and a 12" section of brake line. This puts the switch right next to the master, and within range of the factory harness.

I thought it sounded logical. Remove the rear brake feed line from the factory tee on the frame. Add the above mentioned line and fitting to the existing tee to take care of the brake switch. Add a piece of line between the rear feed line to the master cylinder. Plumb the front M/C line to the tee just like the original set up.

This is how mine is hooked up. Should work fine.

[Jim Cannon]

Jim,

I found this on BUICKV8 and was wondering what you think....

I incorporated the factory pressure switch into the port on the distribution block where the rear line originally went. I used a female/female adapter (3/16 brake line fitting x 1/8" NPT) and a 12" section of brake line. This puts the switch right next to the master, and within range of the factory harness.

I thought it sounded logical. Remove the rear brake feed line from the factory tee on the frame. Add the above mentioned line and fitting to the existing tee to take care of the brake switch. Add a piece of line between the rear feed line to the master cylinder. Plumb the front M/C line to the tee just like the original set up.

If this all sounds right the only questions I have is will the 67 Riv dual M/C work with either booster? What is this about a seal between the M/C and Booster?

Thanks!

The approach above will work. Like anything, there are multiple ways to do it.

Here is what I recommend:

Keep the factory distribution block on the frame. Remove the line going to the rear axle and plug it. Connect the port on the block that goes to the stock MC up to the FRONT port of the dual MC. You need to fabricate a line to do this, with double-flared ends at both ends. Put some slack in the line by making a Z-shaped portion or a coil The tube nut size on the front MC port is different from stock MC, but is easily obtained. That takes care of the front wheels.

For the rear axle, you want to fabricate a new line that goes from the REAR port of the dual MC down to the frame in the vicinity of the distribution block. Include a coil or a Z for slack. Use a T-fitting style union made for brake light switch to connect the end of your new rear line to the existing rear line that come off of the original distribution block. The 2 union-type ends will be tube fittings. You connect the line to the rear axle to one of them and the line up to the dual MC to the other. It is equivalent to a straight-through union. The T-part of the fitting is 1/8" NPT, not flared tubing. The stock brake light switch screws right into it. The wires on the stock wiring harness are long enough to reach down to the frame by the distribution block. You do not need to splice any electric or cut anything.

To keep the lines from vibrating against each other, I tied the lines to each other with a couple of small zip ties.

I got the 3/16" tubing, the master fittings STN-7 and STN-5, the T-fitting BS-01 and everything from Inline Tube. I might have gotten the plug from them, I don't remember. Call them.

You do not need a proportioning valve for the drum-drum system. Crude proportioning is already included in the wheel cylinder cup/piston diameter difference between front and rear. Connecting lines as I describe will maintain the factory proportioning, for better or for worse. (I used to design brake systems.)

The brake light switch is hard to bleed air out of. Fill it with fluid before screwing into the T-fitting. Try to keep it contacts down until you bleed the system, then invert it.

Regarding which dual MC to use:

You need to remove your stock MC from the car and look at the end of the piston that the booster pin presses against. It will be either a (roughly) 1" deep hole or a 1/4" deep dimple. The new dual MC that you install needs to have that same depth "hole". It will be either one or the other. Trying to put the wrong one in will not work.

If you are keeping your STOCK booster, you need to put an o-ring on the neck of the new MC where it inserts into the booster, or else you will have no boost (due to vacuum leak at the neck). Either move the original o-ring over to the booster or get a new o-ring. The only guy I know that sells this special o-ring is Booster Dewey out in Oregon. You might try NAPA or other places and find it. If you were to "cut" the o-ring and look at the cut surface, it would not be a circle. It would be a small square. So it is not really a conventional o-ring. It is specific to this application.

HTH.

[RivNut]

Nice write- up. Thanks, Jim.

[Guest Kaber]

THANK YOU JIM!!!! This is exactly the information I was looking for.