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Power Booster Mounting

Discussion in 'Early CJ5 and CJ6 Tech' started by CJ Joe, Aug 30, 2016.

  1. Aug 30, 2016
    CJ Joe

    CJ Joe Truckhaven Tough!

    Pinon Hills, CA
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    390
    In the picture below is a power booster I bought as part of a brake upgrade I'm doing on my '68. To the rear of the diaphragm is a bracket and linkage. As I'm at the point were I need to precisely locate the unit I'm wondering if I really need the bracket. Can the booster mount directly to the hanging pedal bracket? The hanging pedals are from a '93 YJ. The hole pattern doesn't quite line up but I can deal with that. The rod would go directly from the pedal arm to the diaphragm like most cars do.

    It just moves the whole assembly a lot farther forward than I'd like. Now that I've been thinking about it
    I don't recall seeing this bracket on any other CJ power brake mod. How have other done this?

    [​IMG]
     
  2. Aug 31, 2016
    47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

    USA
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    What I did was use the pedal assembly from a YJ and mocked it up with a booster. Scroll through this.
    2X4 frame for my CJ2A
     
  3. Aug 31, 2016
    jzeber

    jzeber Well-Known Member 2022 Sponsor

    Morgan Hill, Ca
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    I used a booster and bracket from a 1998 Cherokee. I ended up using the brake pedal that came with it but kept my through the floor clutch pedal. I really like the AA chain pedal I have. I made a brake pedal to sort of mirror the original location of the through the floor. I recently had to modify it because it was not getting the full travel need on the M/C.
    I had pictures on Picasa but cant seem to access them. I'll see if they are around somewhere.
     
  4. Aug 31, 2016
    tarry99

    tarry99 Member

    Northern California
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    The adapter is commonly used when you have to lower the booster for hood clearance or get away from the firewall for other clearance's in some car applications............it also is a ratio changer.............if you have to go direct to the firewall that's OK ..............but you must maintain the proper pedal ratio for power brakes..........which is about 4-5:1..........if you have manual brakes now or the pedal set your using is from a manual brake application the ratio on that set will be more likely about 6:1............the pattern between the two are different as you have already found out.........

    The last one I did I cut out that center section in the pedal set and replaced it with another piece of steel drilled to the correct pattern...........in doing so you can also move the center bore hole and center line of the master cylinder push-rod up/ down to correct the pedal ratio..............
    If you notice I also tied the front part of the pedal bracket to a brace going to the cowl above.........this eliminates the need for a much larger plate on the other side of the firewall to secure the Booster , Master Cylinder and Pedal Set.

    [​IMG]
    [​IMG]
    [​IMG]
     
  5. Aug 31, 2016
    47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

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    The stand off on the YJ assembly is there to allow the clutch master to fit behind the vac booster. It actually worked out real well for me.
     
  6. Sep 1, 2016
    1955jeepcj5inabox

    1955jeepcj5inabox New Member

    Surprise Arizona
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    Where did you get your booster?
     
  7. Sep 1, 2016
    CJ Joe

    CJ Joe Truckhaven Tough!

    Pinon Hills, CA
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    I'll ditch the bracket and extra linkage. I prefer to keep it simple. Now I see what Terry did with a new interior plate (some how I missed that on my earlier research). And I really like the secondary attachment at the cowl. That would make a big difference.

    One of my goals is to get the pedals as close to the original location as possible. Sixteen years of muscle memory knows exactly where those pedals are and I can cover both gas and brake when needed. That puts the brake and clutch on either side of the steering column. Which doesn't work for the pedal set bracket without extensive mods. I have some .750" precision ground shaft as the original uses and some cold-drawn seamless at .750" ID so I think I'll just fab the bracket from scratch. The pedals have good bronze bushings so I'll just shorten them and put the linkage point were it's needed for the correct ratio.

    Thanks for your input guys!
     
  8. Sep 1, 2016
    CJ Joe

    CJ Joe Truckhaven Tough!

    Pinon Hills, CA
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    From the Jeep Guy The Jeep Guy Home Page

    I bought 11" rears with e-brake from him too. They seem to be getting scarce and he had a pair.
     
  9. Sep 1, 2016
    tarry99

    tarry99 Member

    Northern California
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    Normally those later CJ & YJ pedal sets have too long of a pedal arm length wise...........I think close to 16" from the pin to the foot pad.......in an early Jeep I think around 13 -14" is all you can use with the slanted firewall...........the clutch pedal can be shortened and moved over near the old floor location by just bending the pedal arm.
    [​IMG]
    The brake arm can also be made to work but also needs to be offset over towards the gas pedal on the other side of the column...............not much room for both brake and gas pedal on that right side. Here is what I was working on prior to changing over to a 4L70E Transmission..........Of Course the location of the Booster and Master cylinder on the other side of the Firewall pretty much needs to stay left of the column for clearance at the motor for valve cover removal and also do to the lack of flat Real Estate out there to bolt the Booster to..............As you can see both clutch and brake pedals are pretty much lined up with the old holes in the floor.
    [​IMG]
    Never finished them and they still needed to be cleaned up , but as you can they would have worked...............Just the same it will give you some Idea's for your project.
    [​IMG]
     
  10. Sep 23, 2016
    Desert Runner

    Desert Runner Member 2024 Sponsor 2022 Sponsor

    Hickory, Pa
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    Would you measure the bracket hole distance for me? One end sb 2" on ctr the other is 3 3/8???
    I'm looking at getting a bracket, but I need to know the hole distance.
    Thanks
    Jay
     
  11. Sep 27, 2016
    CJ Joe

    CJ Joe Truckhaven Tough!

    Pinon Hills, CA
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    Jay, I'm not sure exactly what dimension you need. Is it these? 2-7/8" slotted x 4-1/4". The booster is 3-3/8" square.

    [​IMG]
     
  12. Sep 28, 2016
    Desert Runner

    Desert Runner Member 2024 Sponsor 2022 Sponsor

    Hickory, Pa
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    Thank you, that is exactly what I needed. (y)

    I have access to a booster, now I know the bracket is set to work with it, I just need to remeasure the holes on the fire wall but I think the other end will mate. Which means I can add the booster by simply getting the bracket.

    Thanks
    Jay
     
  13. Oct 1, 2016
    eti engineer

    eti engineer Member

    Great Central...
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    Tilt Steering.png





    The PO had a power booster in a pile of stuff he gave me (see pix below). It was his intention to replace the original brake system with the vacuum booster and hanging pedals. The booster assembly and hanging pedals were all on a plate where he had cut the whole assembly out of a donor car. Since everything was all in one piece, it made sense to me to cut a hole in the firewall and weld the whole assembly in place as it was. The small reservoir at the far right of the pix is not being used at the moment. If I can ever find the right parts to do so, I will put a slave cylinder on the bell housing, put a new master piston in the reservoir unit and make my clutch hydraulic. I have fabricated a linkage to use the existing clutch assembly with my hanging pedals. Wasn't as bad as I thought it might be. Just another idea.

    The above pix shows the hanging pedals when they were in the process of being installed and adjusted to work. I also added saginaw with tilt steering.
     

    Attached Files:

    Last edited: Oct 2, 2016
  14. Mar 4, 2018
    shaun

    shaun Member

    Lebanon, Ohio
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    I’m about to hang my pedals on my 66 cj5. I see a couple of ways. I like tarrys way. Is it all welded and what’s the easiest path to take.
     
  15. Mar 4, 2018
    tarry99

    tarry99 Member

    Northern California
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    Shaun, Got your PM..........Post some pictures of what you have to work with......pedal set and size / diameter of booster ..........some folks will use the linkage adapter shown above in #11 and some will not..... the Linkage adapter to the best that I and others can figure out does two things.........moves the booster away from the firewall which could be more obvious in some vehicles where clearance is a problem and can also correct pedal ratio............pictures would be great.
     
  16. Mar 5, 2018
    shaun

    shaun Member

    Lebanon, Ohio
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  17. Mar 5, 2018
    shaun

    shaun Member

    Lebanon, Ohio
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    390
  18. Mar 5, 2018
    shaun

    shaun Member

    Lebanon, Ohio
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  19. Mar 5, 2018
    shaun

    shaun Member

    Lebanon, Ohio
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    Looking to get a nee booster. Any one in particular. Summit has one that comes with a dual MC, thought about getting that one. I do have one on hand but I think the booster is shot.
     
  20. Mar 5, 2018
    tarry99

    tarry99 Member

    Northern California
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    Looking at the pedal set I would guess that came off an Early 80's CJ that was using a factory Hydro clutch or at least that bracket hanging off the Left side looks like the factory one............Those pedals are about 16" from the pivot shaft to the foot pad.............and for an early CJ they will probably be too long and hit the slanted portion of the floor to firewall too early to fully release the clutch.....need to be about 14" +/- to make that sweep but that will all depend on how high up on the firewall you can mount the pedals......................keeping in mind the size of the booster and how that impacts hood clearance above...........the booster in my picture above is a dual 8" and that is a good size for the project and has a little extra reserve for stopping and if you run at high altitude it will store a little more vacuum...........still need about 19-21 inches of vacuum off the manifold or carb base....

    FYI: If you notice On my pedal set I left the clutch pedal arm full length and just dog-legged the arm in the press over some to get some floor clearance & alignment to get where the old pedals came out of the floor...............Jeep early seating is a little lower than the intermediates and likewise the slanted portion of the floors & steering column location are also different...........so your knees may hit the steering wheel trying to get on the pedals.......Last thought you want to maintain a 6-7:1 ratio at the hydro clutch pedal and about a 4:1 ratio at the Brake pedal.....and on your Master cyl.........that should be suited size wise to accommodate the brake system your running.......be it discs or drums or both............hope that all helps.
     
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