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

Power brakes

Discussion in 'Intermediate CJ-5/6/7/8' started by quimbypond, Aug 18, 2013.

  1. quimbypond

    quimbypond Member

    I'm thinking of doing the power brake upgrade in my rig. Currently, I'm running 11" drums all the way around with 33's. A little more stopping control would be nice!
    I've checked out a lot of threads on the subject and noticed that there are endless combinations possible. Right now I have a junk booster and MC (w/ firewall bracket and rod) from a '76+ CJ7. Any ideas?
     
  2. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Mmm. The only power brake parts that will just bolt on are from a '72-75 CJ-5, and those are very scarce.

    Everything else has to be adapted, to some degree. If you want to use the parts from a '76 or later Jeep, you'll have to use your ingenuity. They are not the same as what was used before '76.
     
  3. quimbypond

    quimbypond Member

    Yeah, I assumed things would be a little different. It looks like the mounting holes in the firewall match the holes in the 76+ booster bracket. Not sure if the push rod is the same length.
    Any recommendations on a junk yard booster and Mc I could use? I also remember something about 10psi valves???. thanks
     
  4. nwedgar

    nwedgar Now with TBI!

    I know you already have some of the hardware, but why not just swap to disks on the front. I found that it helped my '74 quite a bit.
     
  5. johneyboy03

    johneyboy03 The green beast

    Hum a 76 and more should do the trick. I did the upgrade on my 75 using a YJ booster (same as CJ). For the booster you need to drill the 4 holes in the firewall. After that i modify the brake pedal (just drill a bigger hole) so i can use the Oem brake swich. Those were the only modifications i made to fit the booster.

    For the brake itself i suggest you to swap some disk brake from a 1976 with the 6 nuts locking hub (the number of bolt the manual lock as on it). You need the get both knukkle from the donor. Knukkle are bolt-on, on any CJ dana 30. You also need the outer axle shaft from the donor.

    For brake line make sure you use the prop valve and the galiper brake line from the donor.

    Swapping disk brake is basicly a job of disasemble and assemble no need to fab anything.

    I can take some picture tomorow if you want.
     
  6. quimbypond

    quimbypond Member

    Pics would be great! I've never swapped brakes.
    i have 2 junk CJ7's as donor vehicles.
     
  7. quimbypond

    quimbypond Member

    Oh yeah, you mentioned that you had to drill the holes in the firewall. Did you use the bracket, or go directly on the firewall with the booster? Another question....... I have edelbrock intake and a Holly carb, so I'm wondering if ill have any issues with vac lines to the booster?
     
  8. Boyink

    Boyink Super Moderator Staff Member

    I had power & 11" drums on my '66 CJ5 way back when. Worked well in normal use, but drums are still drums off-road.
     
  9. quimbypond

    quimbypond Member

    Ok, forgot to mention that I have a 44 up front, so my donor rigs won't help. I did pick up a YJ booster/mc/prop valve at a junk yard today for $30. It's not the dual diaphram from a '95, but it should help a little. Definitely worth a try for $30.
     
  10. IA2003

    IA2003 Member

    I am installing a hanging brake pedal with booster in my '58 CJ5. Where do I connect the vacuum line from the booster on the Fhead? I have read every thread on brake boosters and still have no idea where that connection is made. Thanks in advance.
     
  11. tarry99

    tarry99 Member

    Most pull vacuum from either at or under the carb. or the manifold........Not sure what you have for a Booster and what type of brakes downstream your powering up..........needs at a minimum are about 19-21 inches of vacuum to operate the system......a dual chamber booster will recover quicker............... Get a gauge and find a suitable port.
     
  12. IA2003

    IA2003 Member

    I have 4 wheel disc brakes. I don't have a booster or master cylinder yet. I am looking for a setup that will fit. There is not a whole lot of room on the engine side of the firewall for a booster and master cylinder setup. It looks like it will hit the top of the engine.
     
  13. tarry99

    tarry99 Member

    A dual 7 inch booster may be what you need...........sometimes the room inside the engine compartment dictates where your swing pedals must be mounted , no mention on clutch pedal so assume your going hydraulic? (once inside you can offset the pedal for convenience) .........also you should pay close attention to the correct pedal ratio for power brakes which should be about 4-5:1................meaning the length from the point of push rod contact to the MC to the fulcrum point above divided into the length from the fulcrum to the foot pedal push point should have a ratio as mentioned above..........Early Jeeps also have slanted floors that will give you a little ache but it can all be done just have to go about the process slowly with tape measure in hand.


    Note: Sometimes in tight spaces a Hydro-vac system can be used.......they basically mount in the same location, are much smaller and power up from a power steering pump.............which I don't know you have.............just a thought!
     
    Last edited: Mar 29, 2014
  14. IA2003

    IA2003 Member

    Thanks for the info. I do not have power steering and I just replaced the entire clutch and I am happy with its function so I will keep it stock for now. How can the brake pedal be offset? In a perfect world I would mount the MC and booster much closer to the fender side than it looks like I can.
     
  15. tarry99

    tarry99 Member

    That would depend on what pedal set you have...........most sets swing from a common fulcrum point. Hard to explain but I'll try: I have taken that point and extended it to the right so now the brake pedal is hanging off the outside of the right side of the main pedal bracket........Of course the pedal has to be modified to do so and a new loose tube made to be installed where the old pedal was inside the bracket.........off of that new tube a bracket is made that does two things. 1) Its made to allow centered contact with the center of the M/C so a push rod can be installed to push the master cylinder and 2) creates a bridge over to the new pedal location so that both can be tied together and work together.......It can be a little complicated to get the split pedal installed so that it is removable. But It can be done and I have done several using the stock Jeep swing pedals sets from CJ's & YJ's...............this essentially puts the pedal on the right side of the column........if the offset is not to great sometimes bending the pedal over or adding some length can also be done...........Its just a process that grows & develops as your need for how much offset becomes known.
     
  16. Posimoto

    Posimoto Hopeless JEEP Addict

    If I'm not mistaken, D30 knuckles will bolt up to a D44. I'm using D44 knuckles on a D30, so I'm pretty sure they will go the other way too.