Brake lines

[psychostang]

For anyone who has a dual channel M/C, what parts and pieces did you use to connect the front and rear lines to the Prop Valve?

 

Also, for those who have converted to rear disk, did you order a new axle line for disk brakes or did you reflare the stock line?

Edited October 21, 2018 by psychostang (see edit history)

[RivNut]

I think that the most common way is to run the line for the front brakes just as they were with the single reservoir system using the original distribution bock. For the rear brakes, just block off the port in the distribution block to the rear brake line, and using a union,  run the line from the master cylinder directly to the brake line to the rear brakes.

 

The difference in the rear disk brake setup would be that you have to use a disk/disk master cylinder and insert a proportioning valve in the lines. I'm sure there's an illustration on Google that would show this.

[psychostang]

Ok, so just run the front brake line from prop valve to original distribution block and block off rear port.  Then run rear line from prop valve to a new union with rear line.  

 

What about the rear axle line?  Do you just cut and re-flare with new tube nut for disk brake application?  Do any of the brake line manufacturers make a rear axle line specific for disk brakes?

[RivNut]

8 hours ago, psychostang said:

Ok, so just run the front brake line from prop valve to original distribution block and block off rear port.  Then run rear line from prop valve to a new union with rear line.  

 

What about the rear axle line?  Do you just cut and re-flare with new tube nut for disk brake application?  Do any of the brake line manufacturers make a rear axle line specific for disk brakes?

You do not have a proportioning valve on on drum brake car.  There's a master cylinder with one line going from it to a distribution block.  There are three lines coming from three ports on the distribution block. One port distributes fluid to the right front, a second port distributes fluid to the left front, and the third port distributes fluid to the rear.  In the rear a "T" splits the line to each rear wheel.

 

Use the distribution block as designed to get fluid to the front wheels.  Put a plug into the port that was used for the rear line.   From the master cylinder, run a new line directly to the existing line to the rear.  The existing line will already be flared and have a fitting on it.  You'll need to add a fitting and flare your new line and join the two with a union.  Spend the extra $$ and buy yourself a really good flaring tool that will make precise double flares and a quality tube bender.  The cheap ones will cause you nothing but headaches and money.

 

I've yet to figure out why any one needs rear disks so I have no info for you.

[Riviera63]

10 hours ago, psychostang said:

For anyone who has a dual channel M/C, what parts and pieces did you use to connect the front and rear lines to the Prop Valve?

 

Also, for those who have converted to rear disk, did you order a new axle line for disk brakes or did you reflare the stock line?

 

Here is the procedure Jim Cannon suggested. As he said there are many ways to do this. I followed this procedure with my car. It was inexpensive and worked very well. 

 

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(the T-fitting comes with a new brake light switch attached) 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]

What you need to realize in Jim's write up that he uses a T fitting in the line to the rear wheels for the hydraulically actuated brake light switch which is unique to the 63 Riviera.  In 64, the brake light switch is actuated by the brake pedal arm.  If you have a 63, you'll need to insert the T for the brake light switch; if you have a 64 or 65, the T is not needed.

 

There is a complete write up, including scaled drawings for a bracket, in the Tech Tips section on the ROA website for this operation.

 

If youre doing this on a drum/drum system, as Jim did,  this does not improve the braking of your car, it's a safety factor in case one of your lines breaks.

 

[SwedeDownUnderR63]

Here is an alternative for a ‘63 in case one would like to go further and add disk brakes to the front and a dual master cylinder:

Wilwood Proportioning Valve w/Brake Light Switch.

This allows for adjusting the brake power between front and rear whilst also having the brake switch built in. Works fine for me.

http://www.freakride.com/product/wilwood-proportioning-valve-wbrake-light-switch/

 

[RivNut]

To me that says BIG BUCKS.  I have the Scarebird adapters and I pirated the entire brake system, master cylinder to wheels, from a '76 Riviera.  The best thing about this is that EVERY part is available at the jobber in every little town and port.

[Riviera63]

2 hours ago, RivNut said:

What you need to realize in Jim's write up that he uses a T fitting in the line to the rear wheels for the hydraulically actuated brake light switch which is unique to the 63 Riviera.  In 64, the brake light switch is actuated by the brake pedal arm.  If you have a 63, you'll need to insert the T for the brake light switch; if you have a 64 or 65, the T is not needed.

 

There is a complete write up, including scaled drawings for a bracket, in the Tech Tips section on the ROA website for this operation.

 

If youre doing this on a drum/drum system, as Jim did,  this does not improve the braking of your car, it's a safety factor in case one of your lines breaks.

 

 

Good catch Ed, I should have mentioned that about the T not being needed for the 64-65. 

 

The write up on the ROA website is essentially the same as what Jim outlined but somewhat more complicated. With the above method you don't have to replace the distribution block and fabricate a mounting bracket, your original distribution block is utilized. Also, if you are doing this on a 63 you do not have to mount and rewire a new brake light switch as outlined on the website. An original style brake light switch is included with the T from Inline Tube. The wires that ran to the switch on the original master cylinder are long enough to reach the new switch in the T. 

 

Bill