Advice on dragging rear brakes

[mk_not_a_robot]

This issue does not seem to be severe, but I would like to fix it.

Both rear brakes drag, the driver side has a heavier contact spot where you can hear a scrape / chuffing sound of pad on rotor once per rotation.

The passenger side is a steady light grinding sound.

Both sides spin "freely", and it isn't grabbing the rotor like a brake that is "stuck" in the normal sense of the word.

But, it's still not normal.

So far I have cleaned off the slider pins and placed a fresh batch of silicon grease on all the rear pins.

I also ground off the sides of the brake pads that make contact with the caliper itself.
I only shaved off a tiny bit, as the inner ones seem to not budge (on either side).
When I first took off the calipers, I needed to wiggle both inner pads free.

This worked for one evening, then the sound was back (but half as intense).

The brake rotors are the original ones, and all 4 have lips on the edges of the rotors, and are discolored with a burnt metallic blue.

I don't suspect the brake lines, mostly because the wheels are spinning with little resistance.

Is this issue due to the rotors only? or is there another problem in her that I need to address?

 

[maestromaestro]

You may have warped rotors (you can confirm by measuring the run-out if you have a micrometer on a magnetic articulating arm) or you may have an issue with the pistons not retracting (this may require rebuilding or perhaps replacing the rears). If this is not it, I'm out of ideas.

 

[PunkST]

If the rotors are as bad as you claim. Toss both them and the pads in the trash its time for new.

 

[Blindeye_03]

Does your steering wheel shake when braking?

 

[maestromaestro]

You may have warped rotors (you can confirm by measuring the run-out if you have a micrometer on a magnetic articulating arm) or you may have an issue with the pistons not retracting (this may require rebuilding or perhaps replacing the rears). If this is not it, I'm out of ideas.

There was a recent thread about brakes just clamping on and not releasing. Turned out to be a brake pedal sensor. You may want to have that checked out - but, first, replace your rotors and pads, and maybe clean/grease the pistons.

 

[Intuit]

The pads have to be installed correctly. If not, they will drag.

Dragging by the way is a big deal, due to the heat being generated.

 

[mk_not_a_robot]

I will replace the front and rears with new rotors, but I wanted to address this problem first.

I could get new rotors, and see if that fixes it like you guys are suggesting.

I don't want to go OEM, since the verdict seems "grippy, but slippery when hot" which I have definitely noticed.
Does anyone have any suggestions for some durable aggressive brake rotors? (I'm not looking for a full track oriented rotor)

Do I really have to replace the pads too? They're not very worn down at all (I replaced them a few months back) and have worn evenly.


As for the brake piston, I have never opened up the brake lines before. how difficult is it to pop off the pistons on the rear calipers?

 

[mk_not_a_robot]

Does your steering wheel shake when braking?

no, it does pull to the left or right, but In think thats the brake vectoring thing (or whatever it's called)

 

[Ford ST]

If it's your rear that is sticking I don't think it's your rotors. The pad may not be installed right it has to line up with that rotating caliper piston, or your handbrake is too tight.

Sent from my LG-LS997 using Tapatalk

 

[Ford ST]

That sound you are describing is normal if the tires spin freely you don't have a issue.
Obviously we don't have drum brakes but if we had drum brakes you actually adjust until there is some very light rubbing.

If you spin the tire like Hell how many rotations are you getting before it stops?
Sent from my LG-LS997 using Tapatalk

 

[mk_not_a_robot]

Probably over 10 I'd say, there is very little resistance.
It's just audible, Oddly enough If I speed up, and hit the brakes it does make it quieter/silent.
it's like if you touched the rotor with something metal like a screwdriver, and you can hear it scraping from the driver's seat.
But, like I mentioned, it is much quieter now that I've greased the slider pins.
It's still there though.

I do believe that the pads are in there correctly. They are the correct type (They are OEM pads)


Maybe it is just the rotors.

 

[Ford ST]

You could try changing the rotors, but if you're getting easily 10 rotations your brakes are fine.
what I mean by fine is you're not going to get any heat buildup, or do any damage. It's a annoyance factor right now but definitely not a mechanical concern.

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[PunkST]

Are you sure its the pads and not the dust sheilds? The sheilds are thin. A big enough rock can bend them and start causing contact.

 

[maestromaestro]

Even when the rear wheels spin freely, there's bound to be some sound - slight contact between the rotors and the pads is inevitable. Unless there is some periodicity to it - say, swoosh-swoosh-swoosh or clang-clang-clang, then you may have a warped rotor or misaligned pad, but otherwise - it's normal. However, what I don't like is that you are saying that this is like scraping a screwdriver against the rotor - that is something that I wouldn't expect. And, you also mentioned the lip on the rotors - now, that is indicative of rotors having been worn WAY past th the minimal specified thickness. Under the circumstances, I would suggest that you look at replacing not only the rotors, but the calipers as well (albeit I can't really explain the sound - you sure that's from the brakes and not something "else"?)

 

[Intuit]

I will replace the front ..........................

The fronts have a particular pad arrangement also.
https://www.fiestastforum.com/threads/brakes-how-to-for-fist.9290/post-364619

 

[mk_not_a_robot]

Even when the rear wheels spin freely, there's bound to be some sound - slight contact between the rotors and the pads is inevitable. Unless there is some periodicity to it - say, swoosh-swoosh-swoosh or clang-clang-clang, then you may have a warped rotor or misaligned pad, but otherwise - it's normal. However, what I don't like is that you are saying that this is like scraping a screwdriver against the rotor - that is something that I wouldn't expect. And, you also mentioned the lip on the rotors - now, that is indicative of rotors having been worn WAY past th the minimal specified thickness. Under the circumstances, I would suggest that you look at replacing not only the rotors, but the calipers as well (albeit I can't really explain the sound - you sure that's from the brakes and not something "else"?)

When I first bought the car, the rotors were noted to have been worn down to that point. The pads did have material left, but were in need of a change.
So I did change those and didn't seen much of an issue to that.

However, the rotors were bluish from heat damage.

The periodic sound has a metallic grind to it, I mentioned something metal like a screwdriver but it really just sounds like a grindstone type of sound.

Are you sure its the pads and not the dust sheilds? The sheilds are thin. A big enough rock can bend them and start causing contact.

I checked the dust shields, no contact. From the discoloration, I think that the rotors might just be warped.

I didn't think so at first because it doesn't look warped from the outside. But it might be warped slightly.

 

[mk_not_a_robot]

The fronts have a particular pad arrangement also.
https://www.fiestastforum.com/threads/brakes-how-to-for-fist.9290/post-364619

I believe I did those correctly, My pads are OEM, as were the ones installed previously, I matched the inside and outside ones together, and checked online to be sure.

Anyone have recommendations for brake rotors?

 

[maestromaestro]

When I first bought the car, the rotors were noted to have been worn down to that point. The pads did have material left, but were in need of a change.
So I did change those and didn't seen much of an issue to that.

However, the rotors were bluish from heat damage.

The periodic sound has a metallic grind to it, I mentioned something metal like a screwdriver but it really just sounds like a grindstone type of sound.

I can't really recall the construction of the OEM pads, but my XP8s have these 2 embedded "pegs" that come into view when there is close to 1/4" or so left of the pad material. They are metal, and they will start scraping against the rotor, making the grinding noise that is unmistakable. You are saying that there is still material left on the pad... Have a closer look tho. Also, is it evenly distributed? If you have a high spot on the rotor, that's where the rubbing may take place, and that's where you may have metal-on-metal contact: BUT, only under braking. Is this your case?

In either case, have another look at the pads and replace the rotors. Blue tint is troubling; that means MASSIVE overheating, and this wouldn't be subtle. You also would likely scrub it off by the pads during braking if it was a transient event; if the tint persists (is it on the swept area or is it off to the side?), something non-trivial is afoot. As I noted before, check your pistons - I'd replace the whole thing. These should be easily sourced (the calipers); heck, I have the OEM ones sitting in a box in the garage somewhere...

 

[ArmedFist]

I have similar issue as well. Did you end up fixing the issue?

 

[Pablo Pistoffo]

I have similar issue as well. Did you end up fixing the issue?

I just saw this come up again- my rears were dragging, and it was because the caliper pins had dried out and were not retracing.
I just pulled them out, changed pads, re-lubed the brake pins, good to go. The pads came with new boots to go around the pin.