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Drum To Disc Question

Discussion in 'Early CJ5 and CJ6 Tech' started by cj6/442, Dec 10, 2017.

  1. Dec 10, 2017
    cj6/442

    cj6/442 Sponsor

    Fallbrook, Calif
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    I have installed a chevy disc set up on my d30 .it had 11" drums . my master cyl is still frame mounted ......on my jeep d30 I run ford hubs way stronger ,no problems .

    do I need a proportion valve ?
    does my drum master cyl have that residual pressure valve that I hear I can remove?
    do I need the 2lb residual valves ? for a non power disc setup ?

    wish I could post a picture is pretty cool
     
  2. Dec 10, 2017
    Focker

    Focker That's a terrible idea...What time? Staff Member

    WA
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  3. Dec 10, 2017
    cj6/442

    cj6/442 Sponsor

    Fallbrook, Calif
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    68 dual frame mount
     
  4. Dec 10, 2017
    Focker

    Focker That's a terrible idea...What time? Staff Member

    WA
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    You should be able to copy my outcome.
     
  5. Dec 10, 2017
    cj6/442

    cj6/442 Sponsor

    Fallbrook, Calif
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  6. Dec 10, 2017
    Focker

    Focker That's a terrible idea...What time? Staff Member

    WA
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  7. Dec 10, 2017
    cj6/442

    cj6/442 Sponsor

    Fallbrook, Calif
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    20171210_172313.jpg 20171210_172313.jpg jeep d30 knuckles with 30 spline cromo axles to ford bronco outer axle/rotors to chevy backing plates to wilwood calipers .
     
    jpflat2a likes this.
  8. Dec 11, 2017
    Posimoto

    Posimoto Hopeless JEEP Addict

    Minden, Nevada
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    You will likely need the residual valve with the frame mounted MC. This keeps the fluid from back flowing to the MC. Otherwise you may have to pump the pedal to get brake pressure every time you apply the brakes. I didn't use a proportioning valve on the rear discs. Doesn't seem to be an issue. So, are those 1 1/8" thick rotors? Can't tell from the pic. I want to do the Ford hub conversion too. Sick of the 6 bolt hubs working their way loose.Is the Bronco outer axle longer than the stock Jeep D30 outer?
     
  9. Dec 11, 2017
    CJ Joe

    CJ Joe Truckhaven Tough!

    Pinon Hills, CA
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    Also consider your existing MC. Was it originally for drums? Disc calipers displace a much larger volume of fluid than the little drum cylinders. You could take some measurements and we could calculate.
     
  10. Dec 11, 2017
    cj6/442

    cj6/442 Sponsor

    Fallbrook, Calif
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    the bronco /ford spindles have bigger bearings I also have bigger 44 u joints ,those are 1 1/8 rotors off a 83 full size bronco ....
     
  11. Dec 11, 2017
    cj6/442

    cj6/442 Sponsor

    Fallbrook, Calif
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    there is alot of info out there ...some say it all works fine no changing the rpv we shall see next weekend
     
    tarry99 likes this.
  12. Dec 12, 2017
    wheelie

    wheelie beeg dummy 2024 Sponsor 2023 Sponsor

    York, PA
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    Your parts list would be awesome for others to do the same set up. P/Ns, year, make, model of the donor truck or whatever you could provide. You seem to have built a pretty stout Dana 30 and I'm sure others would be interested in details.
     
    47v6 likes this.
  13. Dec 12, 2017
    jzeber

    jzeber Well-Known Member 2022 Sponsor

    Morgan Hill, Ca
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    When I still had my under floor M/C the RPV went bad at Barker Meadows and I had to pump the brakes to get pedal.
     
  14. Dec 13, 2017
    68BuickV6

    68BuickV6 Well-Known Member

    Hesperia, CA.
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    Wow, that's a serious axle setup. I've still got my axle pile in the garage....getting closer.
     
  15. Dec 13, 2017
    fhoehle

    fhoehle Sponsor

    Harford Township, PA
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    I have discs with internal spline Ford hubs all around. I used an adjustable proportioning valve and I like being able to compensate for trailers and such. I have a 1967? Corvette master cylinder for a non power brake application, stops great.
     
  16. Dec 13, 2017
    cj6/442

    cj6/442 Sponsor

    Fallbrook, Calif
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    part number? did you install a 2lb rpv as well
     
  17. Dec 14, 2017
    fhoehle

    fhoehle Sponsor

    Harford Township, PA
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    I just looked it up on partsgeek. They have a Centric brand part number 14079-05025146. Manual disc, no residual valve needed if discs all around. The manual proportioning valve can be had at any parts store. Summit has it with part number
    SSBC Brake Proportioning Valves A0707-1.

    I am not sure if it matters but I have hanging pedals so my master cylinder is higher than my calipers.

    My calipers fit an 85 Chevy 1500, as would the backing plates. My spindles are early 70s Chevy but I'm not sure of p\n. Hubs and rotors are Ford 150 late 70s through 87.

    Also I narrowed up a Scout Dana 44 to old CJ width and had shafts shortened and resplined. I then used Dana 30 knuckles with the early 70s Chevy spindles. I think I used regular Chevy Dana 44 outer stub shafts but I can't remember if it was that or late 70s Ford outers.
     
    Last edited by a moderator: Dec 15, 2017
  18. Dec 14, 2017
    cj6/442

    cj6/442 Sponsor

    Fallbrook, Calif
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    reading your posts are fun ...I have so many different parts on my JEEP ..I made a list so I know what to ask for incase we are stranded somewhere ...
     
    FugginJim, jpflat2a and fhoehle like this.
  19. Dec 15, 2017
    fhoehle

    fhoehle Sponsor

    Harford Township, PA
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    Just think of the honor all these other parts now get to have....they get to be part of our old Jeeps! Lol
     
  20. Dec 15, 2017
    wheelie

    wheelie beeg dummy 2024 Sponsor 2023 Sponsor

    York, PA
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    Man alive! I'd like to see a build thread on your front 44 from start to finish. I've been thinking about this for many years but have been told it's hard to make it work on the passenger side. Forget what the reason was. Anyway, I feel like I'm hijacking so I'll not pursue it further.
     
    fhoehle likes this.
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