The pictures below are what my rotor looks like after backing out of the driveway, driving 2 houses down the road, turning around, and back into the garage. These pictures are exactly what my rotor looked like before a couple weeks ago. Since then, I had the rotor turned, and replaced the capliper with a rebuilt capliper. I had assumed that the old caliper had seized, so my first thought was to replace the caliper. I bled it with my Motive power bleeder. I didn't replace the pads though. The pads looked good when I pulled them out. Looking for some ideas on what might be going on here. I can hear a digging/grinding sound coming from that wheel as I went down the street. Should I have replaced the pads? Could it be some other issue that I'm overlooking? It's just the driver's side rear. The other side is fine. Thanks. Andy

 

It looks like the rotor is rubbing on the caliper.
Mike

 

I checked that out when I installed the new caliper. There was spacing on both sides of the caliper and rotor. I also forgot to mention that there is brake pad dust all over the rotor and my wheel. I'm running the Hawk HPS ferro-carbon pads.

 

some dumb PO had replaced the rear rotors on mine but didn't grind off the old rivets. i didn't realize this at first when i replaced them and it was causing it to rub on the pads and wearing out the outer one. this seems like such a dumb mistake i don't know how it was overlooked to begin with, but i guess anything can happen.

 

I know the feeling of dealing with dumb PO handy work. I didnt think about rivets. I dont remember seeing any, but i wasnt looking for any either. Where would the rivets be? I replaced these rear rotors & pads last year in april. I just noticed this not too long ago when i got home one day & my rotor was smoking.

 

Buddy of mine had something very similar. Bought 4 new rotors and mixed up a front and a back.

Anyway, scored one of them on just the outside face by touching the caliper somewhere. Only went about 1/2 a block and came back.

Turns out he mixed a front and a back, the front worked on the back but the back didn't work on the front (or maybe the other way around)

I went over to his place and we did a lot of head scratching until we popped off all the wheels and started checking and that's what the problem was, two opposite corners ended up switched (visually looked the same until you actually started measuring and putting them up to each other)

Might be worth a check, it looked a lot like that photo
Mooser

 

I will check that out. The only thing that is puzzling me is that these have been on since april of last year, and its just now showing up. I prob drove it 3-5 times a week all summer & most of the fall. I will look into the correct measurements on a rear rotor. Been thinking that i might buy new pads to replace the ones that are on it now. They looked fine, but after all this they prob wont be very smooth or even. Thanks for the replies. If anyone else has any ideas keep them coming. Its much appreciated. I want to get this fixed so i can get my hooker headers & side pipes on.

 

Sorry, thought they were new.
Shouldn't be this issue (front/rear) if they were fine before.
You've replaced the caliper so let's go with that being ok.

Your calipers are nicely painted, can you see what was rubbing on the rotor?

If it's the pad that's doing the damage, check to see if there's any foreign materials stuck in it, maybe picked us a small stone or ???

Is the brake sticking on? Check the flex line, been known to rot on the inside and act like a one-way-valve. Personal experience with that one, not every time but frequently it would lock the fluid in the caliper and leave that brake on, looked new from the outside but all torn looking on the inside.

Broken or loose caliper mounting bracket / bolts?

Excessive play in the spindle? (not sure about this) if the spindle was somehow moving outward it would take the rotor with in but the caliper would stay still. Don't know how that would happen, failed bearing or worn spindle

Not sure what else could mark the outside of the caliper like that.

Did anything chance when it went from good to bad?
New tires, rims, shocks, bump a curb, gain 100 pounds? Change something totally un-related?

How's the clearance on the caliper with the wheel off can you see it what might be touching?
If someone applies the brakes can you see anything move/twist on the caliper?

Just some random guesses

 

Cant necessarily see whats rubbing on the rotor. Theres plenty of spacing between the caliper & rotor. Could be moving when applied though. Gonna have to get someone to apply brake while i watch it.
Funny you mention the flex line. A buddy of mine just brought that up a little bit ago. Gonna pick one up and replace it. Shouldve done that anyways.

No play in caliper when tightened. After i bolted it back together the other day it was nice and snug with no movement.

Gonna take a good hard look at the pad on that side next chance i get to be sure nothing got stuck in it.

Also, i did get new wheels & tires on it, but they were put on last sept. If wheels were the prob Im sure it would show up before now.

 

I think Mooser might be on to something. I had EXACTLY the same scoring on my rotor when the back and front were switched. If you remove the rotors,there should be a 0.1 inch difference in the offset. Check this by measuring the inside depth of the rotor to the hub. IIRC the back one should be shallower.

Also check your front rotor. You may well find a corresponding score on the inside face.

 

Just pull the caliper off.
That looks like heavy metal to metal galling with no telltale heat. You should have corresponding marks on the culprit.

 

Take the wheel of and take several pics from above the caliper looking down at the pads. It looks like the ear of the caliper bracket is rubbing.
Mike

 

If you keeped the same pads check the pad for metal inbedded.Sand them until the color is uniformed and reinstall

 

the rivets hold the rotor to the flange. there are 5 rivets i believe, spaced between evry wheel stud. if you take the rotor off you'll see what i mean. you can see the heads of them in the parking brake area. the rivets were the way the factory held the rotors in place, but when replacing the rotors it is not necessary to re-rivet them in place, as the tire holds it on just fine when the lug nuts are tightened.

 

Just another random possibility
Any chance the pad had a wear-indicator tab on it that caught one of the rotor grooves and got pulled between the pad and rotor and is stuck there now?
I know, pretty weak..

 

no it ain't weak, it's actually a good thought. unfortunately for this idea, is that i recently read somewhere that there are no wear indicators on the pads for these car. don't know when they started doing it either. it was atleast later than 75, because mine don't have them.

 

One of my first thoughts was a wear indicator tab, but they are non-existant. I was planning on tearing into it all day tomorrow, but now ive got a meeting all morning. I will keep this updated, and post pics as i tear it apart. Thanks again for all the suggestions.

 

Tore into the brakes today. Here's what I found.

Pulled the pads out and there appears to be plenty of spacing between the ear of the caliper and the rotor.


Next is the pic of the pad on the one side where the rotor is getting dug into.


Pulled the caliper off and saw what is causing the problem. The ears of the caliper, on the side closest to the wheel, is what's rubbing on the rotor. It is easy to notice since I had just painted the caliper before I put it on.



I checked the mounting bracket for the caliper and didn't find any cracks, and there was no play in it when I grabbed it and tried to move it around. The wheel studs are good and solid.

I don't see how the caliper would be moving around with everything seemingly solid. I didn't get a chance to have someone press the brakes to see if it moved, but the grinding noise that I heard when driving was constant, even when the brakes weren't pressed.

Could it be from the wheel not going on evenly? Allowing the rotor to wobble or just be crooked. I've put on and taken off wheels many times. It's not rocket science. Standard star pattern when bolting wheel on. I would like to think I'm not screwing that up, but.....lol. I appreciate the input.

Thanks.
Andy

 

Well if the wheel / rotor went on crooked it should have rubbed on one side, not all the way around
If some crud fell behind the rotor, again it should have touched part way around
The mark on the rotor look to be all the way around meaning the rotor is straight out or the caliper is in.

The caliper is marked on both ends so it was on straight

Hate to go back, but are you sure a front and rear rotor didn't get switched?

You said freshly painted caliper, front and rear caliper switched? (not even sure if that's possible)
washer/lock washer between the mounting bracket and the caliper

Mooser

 

Mooser could be right. If not then something is causing that rotor to sit further outboard than it should. Either that or the caliper is sitting further inboard than it should. I really don't think that is too likely.