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Discussion Starter · #1 · (Edited)
Friday coming home from work as I was coasting at 30mph, with foot slightly on the gas, I heard a very loud thud come from the rear/right of the car. Then a violent shudder nanoseconds after the noise.

I thought I'd lost the rear/right tire, or, one of the air bags I had installed in the rear springs for towing a few years ago. But nothing like that had happened.

I did not use the car again until Sunday. Driving experience was fine for the first 15mins, then when attempting to brake, the pedal got soft, slowly sunk to the floor, as it did so, the front brakes locked up 3 times, enough to momentarily stop the front wheels from spinning, then the ABS kicked in and you could hear the subtle vibration of that as the pedal got firm again.

This now happens just about every time I apply the brakes. I can tell when it's going to happen. If, when I apply the brakes, the pedal is hard, it doesn't happen. However, if when I apply the brakes, and the pedal starts out soft, it slowly sinks to the floor, braking power is vastly diminished, the front brakes lock up a few times as the pedal continues to the floor, then gets firm again. No ABS light at any time.

Getting back to the rear/right. I now hear what sounds like the rear shoes dragging inside the drum all the time now. I don't hear any change in that sound from the rear/right when I apply the brakes either. Twice now since this has started, I've heard a thud from the rear/right while driving, then the shudder, no braking involved. Could a shoe be loose and floating around in the drum? If I had a leaking wheel cylinder, I'd loose the brakes wouldn't I? I'm going to be pulling the rear/right wheel and drum in a few minutes to see what's going on. We limped home yesterday in the dark, and haven't had time to look at it. Didn't sleep much last night thinking about this one.

Two weeks ago I replaced the front rotors, calipers, bearings, and pads. Then flushed the brake lines for just the front brakes. I had DOT3 in the lines at the time, and I used DOT4. I know I can mix the two. I flushed the lines until the fluid came out clear. For the past two weeks, the car has stopped w/o any problems.

Could I have damaged the proportioning valve that maintains the proper brake line pressure between the front and rear brakes by only flushing the front brake lines?

Any ideas? I'm going in...

RustyFuryIII
 

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Good luck. no real idea here. I did have a brake shoe that peeled loose once and caused some of those issues.
 

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Pull the drom, I bet what ever it is will fall out!
 

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Discussion Starter · #4 ·
Yup, pad let loose from the shoe. Guess it got jammed between the drum and shoe. Going to be picking up new wheel cylinders, shoes, shoes/spring kit and drum in an hour or so.

Not sure why the intermittent soft brake pedal and lockup of front brakes. We'll see after I get it back together and bleed the rear brake lines.

RustyFuryIII
 
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