2006 Mercury Milan - stuck caliper? Update 12-13

Discussion in 'The Garage' started by MikeyIs4Dcats, Dec 12, 2008.

  1. MikeyIs4Dcats

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    I had new tires put on yesterday and when I went and picked up the car, the shop told me that one of the rear pads is down to metal probably because of a stuck caliper.

    I've replaced pads before on cars, but never a caliper. How can I troubleshoot to make sure that a stuck caliper is the problem? Will this require a replacement caliper, or are they things to try to repair the caliper?

    Are there any other causes of a prematurely worn pad besides a caliper sticking?

    *update*


    I pulled the wheels off today and replaced the brake pads and looked everything over. I'm a little uncertain on a couple of things, hopefully someone has some advice.

    The rear passenger side was the problem. The inner pad was nearly to bare metal, while the outer pad showed about 50% wear, consistent with the drivers side pads. The calipers on a Milan have a piston on the inside of the rotor, and the pad on the piston side was the overly worn pad, so I assume this means the piston was not retracting properly? I lubed the glide bolts, but they had visible grease and I didn't note any other visible signs of disrepair. I will have to special order the caliper assembly, as no one stocks it, so I'm wanting make sure that is the problem before I do so.

    Could there be any other cause here other than a malfunctioning piston on the caliper? Do the glide bolts actually do anything mechanical that may be the source of the issue?

    One other issue, the new pads appeared to have a thicker shoe, and when I reinstalled them with the OEM shims, the wheels were hard to spin. I drove the car for a couple of miles to see if the pistons would readjust but the wheels still were harder to spin than I believe was normal, so I removed the shims. The wheels spin better now. Is this common? I read that on some better pads, that the shims were not required, but these were just some $34 Gold pads from Autozone, nothing special.

    Advice?
     
  2. mooseracing

    mooseracing Golden Member

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    If it is a sliding caliper set up, one pad always wears more than the other.

    If a very large amount worn off, either the sliding area needs to be cleaned and proper grease applied, or the pistons are sticking in the caliper. Sometimes the rubber hoses can also swell and prevent fluid from draining back.

    If the car is driven often I would rule out the sticky pistons (very small chance) and spend the money on a new brake hose, then clean and lube the sliding pins and mounts.

    If you want to be cheap, clean and lube the pins good, reassemble and have someone push on the brake and see how the caliper slides or doesn't. If you don't understand the process look at one side that does work. To make it easier to tell, take a screwdriver or something to push the pads away from the rotor so it has to move more.


    Again the best way to troubleshoot this or compare things it to look at the corresponding caliper on the other side, it will give you detail on how that one should be working.
     
  3. Dr. Detroit

    Dr. Detroit Diamond Member

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    rear calipers are pretty cheap. You should be able to get a remanufactured one for around $100.

    I would replace pads on both sides and put in a reman caliper.

    Is the car out of warranty?
     
  4. MikeyIs4Dcats

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    yes, just turned 40k.

    Thanks for the input guys. I'll check it out tomorrow.
     
  5. MikeyIs4Dcats

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  6. thecritic

    thecritic Senior member

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    If I'm understanding this correctly, the rear passenger side caliper's inboard pad is completely worn out, while the outboard pad is still at 50%. On the rear driver side, the inboard and outboard pads are both worn to approximately 50%. Is this correct?

    In that case, it sounds like the rear passenger side caliper is seizing. This could be caused by a variety of things, such as a caliper piston that is not retracting, a restricted brake hose (unlikely on such a new car) or sticky slide pins (not the problem, according to you). Seized slide pins will cause the inboard pad to wear out quickly as it will prevent the caliper from properly retracting, but if the pins are sliding freely and the bushings are in good condition, then you could probably rule that out.

    I would replace both rear calipers with remanufactured units. While the other caliper may still be OK, it is always recommended that calipers be replaced in pairs to ensure balanced braking. The reason for this is that the remanufactured caliper may perform better than the other caliper and may cause a pull. This is of course, in theory, and is more likely to occur on a higher mileage vehicle than on yours, but I would still replace both calipers if it was my vehicle.

    As for the pads, I checked AutoZone's website and the Duralast Gold pads do contain shims. They appear to be the clip-on style shims that are becoming very common. You should not reuse the OE shims or else they will cause the pad to drag, as you have experienced yourself.

    When you replace the rear calipers, be sure to clamp off the brake line using special pliers. You do not want the brake system to run dry if you have ABS since bleeding an ABS equipped vehicle (if you have run the system completely dry) requires a scan tool. If you do not own the special brake line pliers, then just have a helper keep the brake fluid reservoir topped off. When you install the new calipers, be sure to use the supplied copper crush washer. The one-time-use crush washer plays an important role in properly sealing the system.

    Lastly, I would replace both rear rotors. While you may be able to resurface them, I would personally replace them. The right passenger side rotor has been exposed to some excessive heat (as evident by the failed caliper) so it's possible that the rotor has undergone some metallurgical changes. Therefore, for the $100 or so for a new set of premium rotors, I would just replace them for the peace-of-mind, personally.
     
  7. MikeyIs4Dcats

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    thanks for the input. Your understanding of the pad wear is spot on.

    I re-lube the glide pins, but they were still greased up pretty good. Are the pins supposed to spring back when push against?

    I had once read where you could use a golf tee to plug a brake line...would you recommend that as a solution since I don't have the special tool? Assuming a friend is topping off the resevoir as I plug and unplug it.