Dual Master Help

[wrecker]

I told the counter guy I needed a master for a 1972 J2000. It was about 35 dollars out the door with all the fittings, etc. listed on a sticky on the nuke version of the Zone.

[brute4c]

This is what wrecker is referring to:

From: Mozarkid
Date: Wed Jun 23, 1999 11:02am
Subject: Master Cylinder Data
Source of master cylinder part number: Wagner, Alabama Plant product
engineering.
Master Cylinder: Wagner #F66857
Same unit by other manufacturers: Raybestos #36246, A1 Cardone #A-1-10-1331.
At fire wall: bolts right on, no modifications necessary, use stock brake pedal and push rod.
Outlets are threaded for 1/2-20 and 9/16-18.
Steel nuts for 1/4" brake line are Edelmann #121045 and Edelmann #121049. You will need a double flare tool to make up 1/4" brake lines for them. In the front brake circuit don't terminate 3/16" line at the master cylinder, the brass flair cone is too big. Use 1/4" line and convert to 3/16" line down at the tee fitting you'll need to install down at the frame where the two front lines are near each other.
The primary circuit is the rear brake circuit.
The secondary circuit, nearest firewall, is the front brake circuit. A proportioning valve isn't necessary.
You have several options from here, but you MUST split the lines between front and rear. I replaced all the lines with 1/4", removed the hydraulic brake switch and installed a mechanical switch at the brake pedal (JB welded a limit switch on the steering column directly between it and the brake pedal, a standard cylinder type brake switch can be installed on the existing braket). The wiring from the old switch will reach these locations. The tee located at the left front wheel flex hose connection will need to be changed to one with 1/4" connections.
If you choose to keep the 3/16" brake lines and the hydraulic brake switch: Put the brake switch in the rear brake circuit. Put plugs in the two outlets that went to the front circuit.
CAUTION: If you can't position the hydraulic switch in a manner that will not trap air in the plugged section or the switch section, don't use it. If you want to use DOT 5 brake fluid, be sure to get a new brake switch to avoid the possibility of melting the seals.
If you want to use DOT 5 brake fluid, be sure to get new flex hoses, 2 on front, one at rear
axle.

[rboltz]

That means the 45 degree flare (internal sealing surface) is a different size relative to the line size. If you look inside a fitting you can see the flare surface. It's conical. Like the bottom of a funnel pointing at you. The brake line seals against this with the ferrule nut pushing the line into the sealing surface. Size does matter. A simple adapter will insure the sealing surfaces are compatible.

There are AN fittings (army navy) that are 37 degree. Whole different animal.
Those are single flare verses the 45's double flare. Not compatible at all.

Meaning the 45 degree flare uses a folded over portion to seal. I can explain better if needed.

I understand the flares but without a new master in my hand I did not know how the lines attached. The new master listing says it has 1/2" and 9/16" ports and I assumed, incorrectly, that some sort of fitting screwed in there. After more research I think I now understand.

Is this correct; The brake lines can have different size nuts depending on the line size. So, you use a 9/16" nut for one port and a 1/2" nut for the other. The cone for the flare is already in there. 3/16" line doesn't come with a 9/16" nut so use 1/4" as the write-up says.

If that's the way it is, I wonder if pre-flared lines come with different size nuts or do you need to make your own lines? The 1/4" line would need 9/16" on one end and 3/8" on the other so it will fit into the "T"?

[dahoyle]

Thanks, I'll try NAPA. I was at Autozone.

I don't know how it is in your area, but I would only go to Autozone if I wanted an air freshner, or curb feelers. NAPA has always been my choice for parts, as they are somewhat educated, much more versatile, and willing to go thru the books, rather than just type something into their computer. In addition, I buy so much from them in work related parts, they give me the Jobber price on personal purchases as well, and recently did the same for my wife, just because they knew she was my wife. It also helps that I can just have them deliver everything to the shop, so I never have to run out. Our Car Quest is also set similar, but I don't get the good deals.

In any case, find out who sells parts to small mechanics shops and use them.

I have never left an AutoZone without feeling like I wanted to strangle someone.

[ryanroo]

i am not sure how it is with your master, but with the GM k30 master i used(along with hydroboost from the same truck), the master has a 9/16" nut and a 1/2" nut that both use 3/16" brake line. the nuts are goofy GM parts, normally can't get them at the parts stores. i try to hold on to them when ever i take a truck apart. anyhoo, if you don't have these nuts, you have to use an adapter to get from the thread size of the master down to the threads on the 3/16" brake tube. i have found the adapters at the parts stores.

like i said i am not sure this is how your set up was done in the stock application, but alot of them are. When i parted the K30 i bought for axles and engine i made sure to cut the brake lines and save those funny brake line nuts for when i plumbed my brake system. it worked out great.
Ryan

[rboltz]

Crawled under the truck today to measure brake lines. My distribution block does not seem to match the posted descriptions here and I can't find anything in the manuals. My distribution block has 1/4" line up to the master (posts say 3/16"). A single 3/16" line to the rear and two (2) 3/16" lines to each of the front brakes (threads say one (1). My lines are clean and shiny where not painted and there are old lines disconnected and cut so someone replaced some of them. Am I seeing something that is not stock or are the posts incorrect?

[brute4c]

I know it is poorly covered in the manuals....but....

The block does have a line to each front wheel cylinder, a line to the rear and the port for the pressure switch.

I am pretty sure when I redid my lines some years back that all were the same size....

[rboltz]

I am pretty sure when I redid my lines some years back that all were the same size....

From research, looks like my setup is stock. Line from the master to the distribution block is 1/4". All the rest are 3/16"

[olkaiser]

This is what wrecker is referring to:

From: Mozarkid
Date: Wed Jun 23, 1999 11:02am
Subject: Master Cylinder Data
Source of master cylinder part number: Wagner, Alabama Plant product
engineering.
Master Cylinder: Wagner #F66857
Same unit by other manufacturers: Raybestos #36246, A1 Cardone #A-1-10-1331.
At fire wall: bolts right on, no modifications necessary, use stock brake pedal and push rod.
Outlets are threaded for 1/2-20 and 9/16-18.
Steel nuts for 1/4" brake line are Edelmann #121045 and Edelmann #121049. You will need a double flare tool to make up 1/4" brake lines for them. In the front brake circuit don't terminate 3/16" line at the master cylinder, the brass flair cone is too big. Use 1/4" line and convert to 3/16" line down at the tee fitting you'll need to install down at the frame where the two front lines are near each other.
The primary circuit is the rear brake circuit.
The secondary circuit, nearest firewall, is the front brake circuit. A proportioning valve isn't necessary.
You have several options from here, but you MUST split the lines between front and rear. I replaced all the lines with 1/4", removed the hydraulic brake switch and installed a mechanical switch at the brake pedal (JB welded a limit switch on the steering column directly between it and the brake pedal, a standard cylinder type brake switch can be installed on the existing braket). The wiring from the old switch will reach these locations. The tee located at the left front wheel flex hose connection will need to be changed to one with 1/4" connections.
If you choose to keep the 3/16" brake lines and the hydraulic brake switch: Put the brake switch in the rear brake circuit. Put plugs in the two outlets that went to the front circuit.
CAUTION: If you can't position the hydraulic switch in a manner that will not trap air in the plugged section or the switch section, don't use it. If you want to use DOT 5 brake fluid, be sure to get a new brake switch to avoid the possibility of melting the seals.
If you want to use DOT 5 brake fluid, be sure to get new flex hoses, 2 on front, one at rear
axle.

hi, thanks for this info. i seem to have one distribution block, with two outputs for the front brakes, and one to the rear. to use the 10-1331 cardone master cylinder, can i use this extisting block, or do i need two blocks, etc.? one for the rear and one for the front? or should i use a proportioning valve? do i need to change anything about the brakes themselves at the wheel to use this master? thank you.

[fishtail]

I have done this conversion and it is easy.

Take the line going to the rear of the truck and remove it from the distribution block. Bend it upward 45' about 2 inches behind the fitting. Put a plug into the hole in the distribution block.

Now connect the rear line to the master cyl. port and from the other port down to the upper hole in the dist. block. I used two new lines from the master cyl. and reused the other lines on the truck. You keep the two lines to the front brakes the same as before.

Scott