1. Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.
    Dismiss Notice

Pic Request Please

Discussion in 'Early CJ5 and CJ6 Tech' started by oldtime, Oct 17, 2021.

  1. Oct 17, 2021
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    3,466
    For 1967-71 CJ’s with the dual bore master cylinder only.
    Need to see exactly how and where the factory brake junction block is bolted onto the frame.
    Wanna see how original junction block was positioned and also see how the tubes are routed at the junction.
    Yes I know the brake light switch will be threaded into the junction block as seen below.
    [​IMG]
     
  2. Oct 17, 2021
    Twin2

    Twin2 not him 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Virginia Beach, VA
    Joined:
    Apr 28, 2011
    Messages:
    5,407
    front one
    brake 4 - Copy.JPG
     
  3. Oct 17, 2021
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    3,466
    Huh ? That looks to be on right side of Jeep .
    Oh now I see that’s setting on top of the frame rail.
    I wanna mount it on the inside of my flat fender frame.
    Thanks.
    So anyone have a pic showing how the earlier junction block mounted on the inside of the frame rail ?
    For the single bore master cylinder with the long front wheel cylinder hoses.[​IMG]
     
    Last edited: Oct 17, 2021
  4. Oct 18, 2021
    Cj5dale

    Cj5dale Member 2023 Sponsor 2022 Sponsor

    Knoxville, Tn
    Joined:
    Aug 19, 2021
    Messages:
    573
    This is the front one from my 1970 Cj5. But it’s mounted on top of the frame as well.

    upload_2021-10-18_19-29-34.jpeg
     
    Last edited: Oct 18, 2021
  5. Oct 19, 2021
    colojeepguy

    colojeepguy Colorado Springs

    At the foot of...
    Joined:
    Apr 4, 2010
    Messages:
    7,110
    The junction with the pressure switch is just a split between LF and RF. Just in front of the master cylinder on the inside of the frame rail there's a splitter front and rear.
    20211019_205046.jpg
     
  6. Oct 20, 2021
    Fireball

    Fireball Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Pullman, WA
    Joined:
    Feb 9, 2018
    Messages:
    5,622
    Here's some pictures from my '69. It's somewhat different than the 70/71s picture above. The front brake circuit light switch is in a separate fitting above the motor mount.

    Starting back at the master cylinder. The pipes go forward to the distribution block:
    [​IMG]

    Here you can see the routing:
    [​IMG]

    The distribution block is just behind the motor mount. The rear outgoing line takes a U-turn and heads back along the frame below the master cylinder. The front outgoing line takes an s-bend to the top of the frame:
    [​IMG]

    The front circuit light switch is mounted horizontally in a Tee just above motor mount:
    [​IMG]

    From there the front line goes forward through a clamp on the frame:
    [​IMG]

    Then it goes to a Tee that splits to the left and right front wheels. The left wheel line goes straight down and under the frame to the hose bracket. The right one passes along the back side of the radiator cross frame:
    [​IMG]
     
  7. Oct 20, 2021
    kenb

    kenb Cleverly disguised as a responsible adult

    Detroit
    Joined:
    Jan 22, 2019
    Messages:
    670
    There certainly seems to be a lot of variation in how the lines were set up for the "double safety brake system" or whatever they called it.
     
    Rick Whitson likes this.
  8. Oct 20, 2021
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    3,466
    Yeah lots of variation here and that makes me feel good .
    This is for a modified build but I want it to look factory as much as possible.
    What I have is a rebuilt factory split bore master cylinder mounted into factory brackets onto a CJ-3 frame.[​IMG]

    I plan to run the earlier type 4-way junction mounted onto the inner side of the frame rail because there is an unused 5/16” factory tapped hole at this location as shown.
    [​IMG]

    I will form a tube running from front master cylinder output along the frame to this junction block.
    From there I will simply split the line toward the two wheel cylinders in standard factory fashion.

    The early single bore master cylinders had the brake switch mounted on front of the cylinder.
    I plan to mount my brake switch in place of the plug that hangs down below the front of the split bore cylinder. [​IMG]

    This normally plugged tap should be activated by the front portion of the split bore.
    With switch located as shown I can run a factory CJ-3 rear wiring harness without any modifications.
     
    Last edited: Oct 20, 2021
    Lockman likes this.
  9. Oct 20, 2021
    Lockman

    Lockman OK.....Now I Get It . 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Silver Hill,...
    Joined:
    Dec 4, 2018
    Messages:
    2,698
    Just my 2 cents here . I've learned that in our Jeep applications , ~ 75 % are OEM Stock.....Then variations of applications are often discovered.
    A little bit of creative License is afforded to Folks like us , during our Improvements & Rebuilds.
    ...Richie
     
    Rick Whitson likes this.
  10. Oct 20, 2021
    Fireball

    Fireball Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Pullman, WA
    Joined:
    Feb 9, 2018
    Messages:
    5,622
    Note: The factory dual circuit braking system Jeeps have a brake light switch in both the front and the rear circuits so the lights still work in the event of a circuit failure. They are wired in parallel which also has the advantage of reducing the amperage handled by each switch. A pigtail could be added to the harness for a second switch fairly easily.
     
  11. Oct 20, 2021
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    3,466
    Your saying dual brake light switches ?
    That certainly seems like overkill to me because I have run the single master cylinders for many years with no problems.
    I’m sure I’ll be able to tell if the front brakes stop working.
    If that should ever occur then I can accept that I would loose my brake lights too.
    It would simply be time for an immediate repair.
     
  12. Oct 20, 2021
    Fireball

    Fireball Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Pullman, WA
    Joined:
    Feb 9, 2018
    Messages:
    5,622
    I'm sure they had two switches because federal law requires the lights to work even if a circuit fails. It seems like a lot of manufacturers changed to mechanical switches on the pedal itself around that time.

    I'm not saying you should have two switches. I was just adding info to the thread.
     
  13. Oct 20, 2021
    Cj5dale

    Cj5dale Member 2023 Sponsor 2022 Sponsor

    Knoxville, Tn
    Joined:
    Aug 19, 2021
    Messages:
    573
    Seems like the OP was asking for original routing, etc. which I think Fireball provided. It’s up to the OP to decide if they want to implement the same design the factory implemented?
     
  14. Oct 20, 2021
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    3,466
    I sure appreciate the input.
    I sure never realized they were equipped with two brake light switches.
    But I think I’ll pass on having that much backup.
    Shee Wiz ! Next thing you know we will be running with 8 tires and wheels (just in case).
    Push me around too much and I’ll go back to my single bore cylinder. Ha ha ha !
    Actually I’m still running the single bore on the 1953 4 cylinder Jeep and feel plenty secure with it as is.
     
    Rick Whitson and Fireball like this.
  15. Oct 20, 2021
    colojeepguy

    colojeepguy Colorado Springs

    At the foot of...
    Joined:
    Apr 4, 2010
    Messages:
    7,110
    Twice I've experienced total brake failure with a single bowl master cylinder...never again for me! AnythingI own will have a dual master cylinder.
     
  16. Oct 20, 2021
    EFranzen

    EFranzen Member

    Queen Creek AZ
    Joined:
    Nov 5, 2020
    Messages:
    54
    1969 CJ5 front switch. There's another one located after the master towards the back axle.

    upload_2021-10-20_19-30-27.png upload_2021-10-20_19-31-34.png
     
  17. Jan 11, 2024
    givemethewillys

    givemethewillys Been here since sparky ran it. 2022 Sponsor

    New Kent, VA
    Joined:
    Jun 21, 2005
    Messages:
    1,998
    Bringing an old thread back from the dead, but does anyone know where I can find a replacement for the front junction block that sits on top of the frame? I have one old brake line that I can't get out for the life of me, and I'm worried I'm buggering it up.
     
  18. Jan 11, 2024
    vtxtasy

    vtxtasy oldbee 2024 Sponsor 2023 Sponsor

    Tucson, AZ
    Joined:
    Feb 5, 2006
    Messages:
    1,430
  19. Jan 11, 2024
    givemethewillys

    givemethewillys Been here since sparky ran it. 2022 Sponsor

    New Kent, VA
    Joined:
    Jun 21, 2005
    Messages:
    1,998
    This is helpful, but doesn't look like the one I have. Mine lookes like the one in @EFranzen's post above, with a line front, back, passenger, and upwards (where the brake switch connects).

    The guy at KaiserWillys said it would more than likely be a weatherhead part, and Napa should have it. Napa is saying they don't have anything like it, and haven't carried Weatherhead in a long time.
     
  20. Jan 11, 2024
    colojeepguy

    colojeepguy Colorado Springs

    At the foot of...
    Joined:
    Apr 4, 2010
    Messages:
    7,110
    Should be easy enough to make one with a 1/8 NPT tee and a couple of adapters.
     
    Jw60 and vtxtasy like this.
New Posts