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Brake input from those that did various upgrades

Discussion in 'Early CJ5 and CJ6 Tech' started by mickeykelley, Mar 13, 2016.

  1. Mar 16, 2016
    Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Tantallon, Nova...
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    People have used the 11" Lockheeds on cj's in the past & they stop you nicely but you're still stuck with the manual adjusters same as the 9", if you don't tweak them every thousand miles or so they can get squirrely. I recommned finding a set of 11" bendix for the front.

    H.
     
  2. Mar 16, 2016
    Daryl

    Daryl Sponsor

    Bonney Lake, WA
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    If not doing water crossings, 11" Bendix brakes in good order work really well. I actually believe that matching the right size master cylinder to your system is the most important piece of the puzzle.
     
  3. Mar 16, 2016
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    Adjustment is definitely a key part of the equation. Starting off with all new parts is the biggest factor I believe however. In around 18,000 miles I adjusted the wagon brakes maybe 2 or 3 times.

    Having said that, and actually rereading the beginning post I recommend staying original on the wagon and putting the discs on the front of the CJ. Talk about doing trails in the CJ makes me change my thinking a bit.
     
  4. Mar 16, 2016
    mickeykelley

    mickeykelley Well-Known Member

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    Gotta pull a wheel and look. Not real sure. Right now I'm just trying to figure out a direction on both vehicles AND a budget.
     
  5. Mar 16, 2016
    mickeykelley

    mickeykelley Well-Known Member

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    The hydrovac boost system 61zip is working on over at Oldwillys really sounds interesting. He has it worked out for a wagon, but should be same for CJ. Helps looking to get enough interest before he can place initial order. I don't want to hang anything on the firewall and his will fit down between the frame.
     
  6. Mar 17, 2016
    colojeepguy

    colojeepguy Colorado Springs

    At the foot of...
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    Do you have a link for that?
     
  7. Mar 17, 2016
    mickeykelley

    mickeykelley Well-Known Member

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  8. Mar 17, 2016
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    The hydrovac is basically a remote power booster, using a master cylinder at the pedal and a slave cylinder at the booster. The booster then drives a second master cylinder, which drives the wheel cylinders. Any one of those three cylinders fail, and you have no brakes.

    The dual-circuit hydrovac would have to use six separate hydraulic cylinders to be truly redundant (ie dual like the dual brake master cylinders). It would have to have two separate hydrovacs, one for each circuit. It would need two masters, two slaves, two hydrovacs, and two master cylinders. The hydrovac units would have to be linked somehow to keep the front and rear brakes in balance. This seems very complicated, and introduces a lot of new failure points with all those cylinders.

    JMO - if you want power brakes, convert to hanging pedals, or figure out a way to put the booster at the master cylinder. Another possibility is a hydroboost unit, which is powered hydraulically from the power steering pump. They are very compact, and possibly could be put down by the through-the-floor pedals.
     
  9. Mar 17, 2016
    Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Tantallon, Nova...
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    Not exactly Tim, the pressure from the the MC is fed to both the booster cylinder & a vacuum switch that controls the boost. The booster cylinder is a "pass through" design, if for some reason the booster mechanism fails then you still have pressure from the MC applied to the brake cylinders.

    These things are really quite reliable & have an operating history going back to at least the 1930's.

    For anyone wanting to know more about the mechanics of these things my collection of booster documentation is here-

    Index of /Images/The Sludge Pile/Section_P_Brakes/Hydrovac

    H.
     
  10. Mar 17, 2016
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    Exactly. The CJ5 I had as a teenager had a Hydrovac, and there were some instances where it didn't work good (for whatever reason), but I still had ok brakes. Not great but they still worked.
     
  11. Mar 17, 2016
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

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    This shows how it's done -
    upload_2016-3-17_14-27-40.png

    The way they link the slave and new master is clever - I see how loss of boost would not make for a loss of braking.

    You are still adding two more hydraulic cylinders to the mix, even though they use the same piston. Theoretically you could split the front and rear axles the same way the dual master cylinder splits them, on the same piston. Not sure how you would split the input pressure though.
     
  12. Mar 17, 2016
    Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Tantallon, Nova...
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    There's a colour version of that diagram somewheres on the net that makes what's happening a lot easier to understand, Think I've got it on my home machine, if so I'll upload it later.

    There's a number of different outfits that manufactured these things, Bendix, Lockheed, Girling & probably a bunch more. The Girlings are fairly easy to understand, they're a bit simpler than the Bendix. If you've got an hour to kill watch this-



    H.
     
    Last edited: Mar 17, 2016
  13. Mar 17, 2016
    mickeykelley

    mickeykelley Well-Known Member

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    As I understand this will help with the amount of leg required to accomplish the braking.
     
  14. Mar 17, 2016
    Glenn

    Glenn Kinda grumpy old man Staff Member

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    Yes, it is definitely an assist.
     
  15. Mar 17, 2016
    eti engineer

    eti engineer Member

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    I put a vacuum assist system in mine. I have 9" brakes and 31" tires. I have no problem stopping, but I was taught to downshift when coming to a STOP, so that helps, too. It was an easy fix and while I was at it, I put a hanging pedal assembly in the Jeep. I used the old clutch linkage connected to a T-98 tranny and it works fine. The original hanging clutch assembly was a hydraulic unit and my intent, if I keep the Jeep as is, will be to install a hydraulic assembly in place of the mechanical mechanism I have now, with the cable, etc. The biggest issue is that I need a slave piston that will pull instead of push the throw-out bearing fork. I have seen a couple of vehicles in some research I have done, like the recently doomed Chevy Aveo that uses this type of system, but what I have right now works so well, I hate to mess with success.

    If you can cut the whole assembly out of a compact GM product or anything of the sort and weld it into the firewall, it should work fine. I wish I could tell you which car mine came out of, but it was in the pile of junk the PO gave me along with the jeep when I bought it. 2-27-16 under the hood.png 2-27-16 cockpit view.JPG
     
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  16. Mar 18, 2016
    mickeykelley

    mickeykelley Well-Known Member

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    I'm wanting to keep the stock look so putting one of those giant donuts on the firewall is not an option plus the hanging pedals. Plus on the CJ, the heater is there.
     
  17. Mar 18, 2016
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    My one concern is which brakes will still work the best if the engine was to stall. That is why I changed my thinking to the discs for the CJ front due to the fact that you mentioned trail use which I assume would include hilly/mountain terrain?
     
  18. Mar 18, 2016
    duffer

    duffer Rodent Power

    Bozeman, MT
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    On my B, I ran stock 9" a couple of years, then 11x2 Bendix's for about 10 years (huge improvement), and then 4 wheel power disc's (another huge improvement). I don't know what shoe material Daryl is running on the 11x2's, but the semi-metallic versions I had REALLY sucked after being submerged. With the disc's, no notable difference wet or dry. I looked at a lot of master cylinders when going with the power disc's (in the mid 80's). Wanted something both light weight and compact. The master cylinder/booster for the Shelby versions of the Dodge/Plymouth 024/TC3 fit the bill perfect. I believe that cylinder is identical to one still marketed by Wilwood.

    And yes, when the engine isn't running, you do need a strong right leg. But even though I'm an elderly old fart, that has yet to be a problem.
     
  19. Mar 18, 2016
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    I've had drum brakes not even slow me down after getting wet, so yeah any chance of getting wet and doing on road driving afterwards with drum brakes is generally a bad combination.
     
  20. Mar 18, 2016
    Danefraz

    Danefraz Well-Known Member 2023 Sponsor 2022 Sponsor

    Chico CA
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    Can someone help me out with wet drums? I was taught to ride the brake after water crossings for a bit to dry the brakes... Is this still not applicable?
     
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