Rear brake issues

Discussion in '2005+ Mustang GT 4.6L Tech' started by RLF9409, Jun 5, 2019.

  1. RLF9409

    RLF9409 My blood runs Ford blue!

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    So I took my car through inspection and they told me that my right rear brake is not working as well as the left rear brake. This includes the parking brake.
    Recently I had a frozen parking brake line to the right rear I replaced as well as the parking brake handle/cable that I snapped trying to unfreeze the line.
    I also replaced the right rear caliper. Bled the brakes 4 times now with no improvement. All 4 calipers are getting pressure.
    Pads have plenty of life left on them but appear to have a little uneven wear.
    I just took the brakes apart and bled just the right rear. I noticed that the pin on the pad was not sitting in the slot on the piston so I readjusted but still didn't change anything.

    Could it be the piston getting stuck? It is brand new. I didn't compress it when I firstI am thinking of compressing it?

    Could it be the master cylinder? I would think if it was the master cylinder the left side would be weak as well..

    Thoughts?
     
  2. nbk13nw

    nbk13nw forum member

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    Check the guide pins on the calipers. I had to replace all four calipers due to one or both pins corroding and seizing in the caliper. If they due not move freely it can cause uneven braking and wear.
     
  3. RLF9409

    RLF9409 My blood runs Ford blue!

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    Well upon further investigation it is actually the drivers rear caliper.
    The piston was sticking. Unfortunately not able to free it up enough to make a difference. Apprently causing the left side to engage sooner than the right side giving the appearance that the right side was bad.
    Bought some Stop Tech calipers (a great deal from Rockauto). Now just have to wait for them to get here.

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  4. RLF9409

    RLF9409 My blood runs Ford blue!

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    Update

    New calipers installed. Rear brakes check out and are working as designed. Equal pressure and no issues stopping the car. Confirmed by brake machine

    However...the right rear parking brake still isnt engaging. It has a new cable and visually appears to be working.
    I did replace the parking handle and cable at the same time as the right rear parking cable.

    The parking brake holds the car just fine even on an incline but because it is just the left rear it fails the German inspection.

    I have taken apart the mechanism where both rear cables come together thinking i might have had them switched but they only go in their respective slots.

    The parking brake handle adjustor was drilled in all the way so i loosened it a bit.

    At this point I am not sure what else to do? Seems like an easy system....

    Help!


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  5. RLF9409

    RLF9409 My blood runs Ford blue!

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    In the end it was something simple. The alignment pins in the back of the pad on the drivers rear was not in the hole in the piston

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  6. Derf08

    Derf08 Junior Member

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    Glad you figured it out. I had a similar issue a few years ago when I replaced my rear pads and rotors. I didn't pay attention to the pad nubs aligning on the passenger side the piston holes. Caused dragging issues that I couldn't figure out until I took it all apart and found the slightly out of alignment inner pad. That made me realize the piston wasn't in the right position for the pad to sit flat.
     
  7. RLF9409

    RLF9409 My blood runs Ford blue!

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    It was just weird that the normal brake test showed even pressure on both sides. Only the parking brake showed uneven pressure.

    Also I didnt mention that the right rear seemed to be in between a ratchet for the parking brake. When engaged (before I fixed it) you could push down on the parking brake cable at the caliper about 1/2 inch. I worked both pstons in and out a couple of times and got that slack out. That is when i noticed a mark on the piston where the pin wasn't in the slot.

    I had all the mechanic heads scratching but we all had that "ah ha" moment.

    I hope this helps someone avoid this situation in the future!

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