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Changed brake booster and master cylinder, still having trouble stopping

Discussion in 'CJ' started by Old Crow 1, Feb 4, 2019.

  1. Feb 4, 2019 at 8:48 AM
    #1
    Old Crow 1

    #1
    Old Crow 1 [OP] New Member

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    1976 CJ7 V8 Lifted 33 in tires
    I have an 76 CJ7 with drums all the way around, i have changed out a new booster and master cylinder and i'm still have trouble stopping. now I'm thinking I need the bigger booster double diagram , anybody know if this will help or will I have to change to disc?
     
    Old Crow 1, Feb 4, 2019
    #1
  2. Feb 4, 2019 at 10:44 AM
    #2
    Awrench

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    Awrench Well-Known Member

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    got vacuum to booster?
    No booster check valve issue?

    Issue is just pedal effort OR poor braking ?
     
    Awrench, Feb 4, 2019
    #2
    JKBob 25, aggrex and Bob like this.
  3. Feb 7, 2019 at 7:13 AM
    #3
    OFFGRID

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    OFFGRID Well-Known Member

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    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    A couple things. Originally this was a Mechanical brake system. When you added the booster did you keep the original MC or did you get a new one. If you have a new one, the size of the bowls should be the same as the original, both bowls equal in volume, or 1 large bowl (don't remeber) Front disc and rear drum systems as found in the newer models have a Master Cylinder (MC) with 1 lg bowl and 1 small bowl, (This type won't work with drum brakes). If you are planning on converting to disc in the front the cheapest way will be to find a used axle (maybe $150) and swap all of your parts over to it. If you are lucky enough to find the an axle with the same gear ratio that you have you could just throw it in without having to swap parts. Assuming everything is set up the way it should be and youre still having trouple stopping I would check vacuum like Awrench said, and also make sure your lines are thoroughly bled. If I remember correctly Vacuum to the booster should measure a minimum of 18in/HG.
     
    OFFGRID, Feb 7, 2019
    #3
    aggrex likes this.
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