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Brake Drag

Discussion in 'Intermediate CJ-5/6/7/8' started by Iandavidh, Apr 17, 2020.

  1. Apr 17, 2020
    Iandavidh

    Iandavidh Member

    California
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    So I am definitely having some issues with brake drag. The Jeep will feel fine for the first couple of brake applications but after that there is noticeable resistance when you are driving. Not undrivable but you can definitely feel it(All four wheels). There is also a pretty horrendous brake squeal when the brakes are applied(unrelated?) and every once in a while there will be a bit of a grind and it’ll grab weird when you brake(needs adjustment). After the Jeep sits a while(24 hours or so) there will be no resistance whatsoever on the drums. There should be just a little catch on the drums part way through the revolution when you rotate the wheel in the air right? I have yet to adjust the shoes out to achieve the catch because I fear I’ll make the drag worse while driving.

    Brakes were recently done 3-4 months with all new parts save the backing plate and brake lines. Squeal really began to present itself two months ago. Grind is relatively new.

    What’s the cause of all this?

    Also I didn’t change anything with the pedal ratio and there is about an inch of play with the pedal
     
    Last edited: Apr 17, 2020
  2. Apr 17, 2020
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    First thing I would do is inspect and make sure I had put the parts on right \-way round. Left and right are mirror images of each other, and the self-adjusters are handed too. However, I expect you would not have gone two months of even occasional driving if they were assembled incorrectly. Who did the work? Did you replace the adjusters? Adjusting lever? Adjusting cable? All the springs?

    You should not need to adjust the brakes. They are self-adjusting, and again, if assembled correctly, should remain tight and balanced left-to-right with no intervention. If assembled right, yo shouldn't even need to adjust them at replacement time. I can't imagine that squeal is anything other than the properties of the linings. Drum brakes don't squeal like disks.
     
  3. Apr 17, 2020
    Iandavidh

    Iandavidh Member

    California
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    4C0E6F51-1C5F-4074-93BB-29BEA66D8E6E.jpeg
    All of the adjusters and springs and such were replaced. I had a trusted shop do the work since I put the shoes on backwards and couldn’t figure out why they wouldn’t bleed:gaah:
     
  4. Apr 18, 2020
    Ol Fogie

    Ol Fogie 74 cj5 304, 1943 mb

    Southern...
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    Could there be a problem with the fluid not returning to the reservoir in the master cyl? might be the little fluid return hole in the floor of the master cyl has a bit of trash or fleak of rust in there blocking the fluid from returning from the system lines and relieving the system pressure. if cleaning the return hole does not help you might try a massive bleeding of the entire system so to flush it extremely well to to remove any contaminants. If that still does not help I think I would lift all 4 wheels off the floor and check hand rotation of each wheel. first when then the brakes have not been applied for several hours to see if any or all wheels turn freely. Then press the brake pedal hard a couple of times then recheck hand rotation on each wheel. you might find where the restriction is located.
    Are your parking brake cables working freely, not sticking?
     
  5. Apr 18, 2020
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Hills of NH
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    If the pedal is not returning fully, it might leave the M/c piston blocking the return hole?

     
  6. Apr 18, 2020
    Iandavidh

    Iandavidh Member

    California
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    How do you clean out the return hole?
    The parking brake hasn’t worked the whole time I’ve had the Jeep the pedal is stuck
     
  7. Apr 18, 2020
    Iandavidh

    Iandavidh Member

    California
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    I have about an inch of pedal play before I hit any pressure. Is that too little?
     
  8. Apr 18, 2020
    Ol Fogie

    Ol Fogie 74 cj5 304, 1943 mb

    Southern...
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    I think I cleaned mine with a very thin piece of stiff wire. It was a challenge finding a wire with a small enough diam to pass thru the hole. If I remember correctly I pulled a single wire strand from a hand held wire brush that had very stiff bristles. Use the wire very carefully not to damage the rubber washers inside the master cyl bore.
     
  9. Apr 18, 2020
    Iandavidh

    Iandavidh Member

    California
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    I’ll try that(y)
     
  10. Apr 18, 2020
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Any is enough. One inch? I guess it makes me wonder if the piston/rod is returning completely. For instance, due to bore corrosion inside the rubber boot.

    Have you looked?
     
  11. Apr 18, 2020
    Iandavidh

    Iandavidh Member

    California
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    The master is brand new
     
  12. Apr 18, 2020
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    Is this just the front? Just the back? Just one wheel? Do you have a IR thermometer to check each drum to confirm? Is this a dual or single-circuit system?

    I'm curious about this:
    Before you go anywhere, when it’s free, try pressing hard on the brakes a few times, then immediately go out for a spin. This will tell you if the pressure is accumulating in the lines (that is slowly draining back out when it sits), or if it is heat related. I’m wondering if the rear rubber line is swelled and is accumulating pressure, holding pressure on the rear brakes.

    I had your issue with Mighty Mouse, but it was because of oil-soaked rear pads swelling and grabbing from heat. If your pads are new and clean, I doubt it’s heat related, unless you have a brake line dangerously close to or against an exhaust component?
     
  13. Apr 18, 2020
    Iandavidh

    Iandavidh Member

    California
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    Both front and back is dragging.
    Dual circuit meaning two bowls in the master cylinder right?
    I did hit the brakes a couple times pretty hard before I drove it just now and did not immediately feel any dragging at all but started to feel it just a tiny bit about a mile or so in to the drive(I only drove around the block a couple of times.
    How do you tell if the rubber line is swelled?
    There are a couple of spots(3) where a brake line is within an inch or two of exhaust. One by the muffler, and the other two by the headers and intake manifold.
     
  14. Apr 18, 2020
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    If it’s a 2-circuit (2 bowls) MC and it’s for sure dragging on all four wheels, that’s got to be coming from a fault in, or having to do with, the MC, unless all of your rubber lines happen to be internally swelled at the same time.

    The rubber in those lines can swell as they age and restrict fluid motion. You’ll have 400 psi of pressure moving the fluid toward the wheels, but only a few psi of pressure moving it back, and it might not be enough to squeeze past the restriction.

    This is really hard to diagnose without being there.
     
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  15. Apr 18, 2020
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Hills of NH
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    "New" is always the first thing to suspect, IMHO.

    Again, have you got out-and-under and simply taken a look, see if the linkage is hanging up, or whatever?
     
  16. Apr 18, 2020
    Iandavidh

    Iandavidh Member

    California
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    True. I think it’s from Omix too so quality is always iffy from them. Linkage seems to be fine.
     
  17. Apr 18, 2020
    Iandavidh

    Iandavidh Member

    California
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    My front rubber brake lines are relatively new(couple years). The rear one I’m not sure of its age but I think it was replaced along with the front ones.

    I’m leaning towards the master cylinder being at fault for all this
     
  18. Apr 18, 2020
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    Back in the mid-1970's when I first started driving, my then stock Tux would do this. Starting out driving, the brakes were fine, after about 10 minutes, they would start to drag a little. 10 minutes later, they were dragging a lot, like modereate pressure on the pedal. The pedal was hard, by the way, like no travel, without even pushing on it.
    If I were to park it for 5-6 hours, the brakes were back to normal. I would pull it in to the space, and you couldn't roll it by hand. After it sat a while, it would roll freely. Start driving again, and they would start dragging all over again.
    I eventually "fixed" the issue by flushing the entire system with new brake fluid (yes, it still had the master mounted under the floor). I think the exhaust was close enough that it warmed/heated the master cylinder,
    causing the fluid to expand enough to cause the brakes to drag? The fluid probably had moisture in it from the humidity that caused this to happen. Just my guess.
    Either way, fresh fluid and a full bleed solved my similar issue.
    -Donny
     
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  19. Apr 18, 2020
    Iandavidh

    Iandavidh Member

    California
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    How close was your master to the exhaust?
     
  20. Apr 20, 2020
    Keys5a

    Keys5a Sponsor

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    Fairly close. The exhaust came down in front of the master, then routed under it.
    -Donny
     
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