[beworthy3]

So i had a really hot track day today. Got up to 89. My rotors seem to be cooked. The brakes felt fine the whole day. But as i was leaving the track to go home it sounded like there was a rock stuck in my brakes, even when i was not pressing the brake. I looked and everything appeared to be normal. But my rotor looked horrible on the inside. And near the outer edge there is a significant lip that protrudes up. I figured that might be the issue. The brake pads have about just a smidge under half material left.

Is it possible i warped the rotor? I heard these crack before they warp. 26k miles. 14 track days on them.

[JamesNoBrakes]

Grooved?

[N Camarolina]

Couple of possible causes to evaluate:

1) How heat checked are your rotors? 14 track days is starting to get close to life of the rotors, as the cracks by that point will be enlarging and threatening to make it to the outer edge (potential for a cracked rotor).

2) Are you sure you have 1/2 the pad surface left? The inside pads on and SS 1LE (impossible to see with the wheel in place) tend to wear faster than the outside, and the bottom of the pad (also more difficult to see with the wheel in place) wears faster than the top and becomes tapered. So if you are looking at the outside pad at the top and see 50% of the pad left, the bottom inside pad could well be a lot less than that. If you get down to the backing plate rubbing on the rotor, it can ruin it, which may lead to the noise you are hearing

3) Rock/debris wedged between the pad and rotor. I had this happen to me (ironically right after I had serviced the brakes) and could not believe the awful, metallic, grinding noise it made. Was not easy to dislodge either, but once I got is loose, the noise went away immediately.

4) Warped rotor. Very unlikely. Could be uneven pad deposits, but that type of thing likely wouldn't make the noise right a rock stuck.

[beworthy3]

Originally Posted by JamesNoBrakes

Grooved?

Yes this is a pretty accurate way to describe them

[beworthy3]

Originally Posted by N Camarolina

Couple of possible causes to evaluate:

1) How heat checked are your rotors? 14 track days is starting to get close to life of the rotors, as the cracks by that point will be enlarging and threatening to make it to the outer edge (potential for a cracked rotor).

2) Are you sure you have 1/2 the pad surface left? The inside pads on and SS 1LE (impossible to see with the wheel in place) tend to wear faster than the outside, and the bottom of the pad (also more difficult to see with the wheel in place) wears faster than the top and becomes tapered. So if you are looking at the outside pad at the top and see 50% of the pad left, the bottom inside pad could well be a lot less than that. If you get down to the backing plate rubbing on the rotor, it can ruin it, which may lead to the noise you are hearing

3) Rock/debris wedged between the pad and rotor. I had this happen to me (ironically right after I had serviced the brakes) and could not believe the awful, metallic, grinding noise it made. Was not easy to dislodge either, but once I got is loose, the noise went away immediately.

4) Warped rotor. Very unlikely. Could be uneven pad deposits, but that type of thing likely wouldn't make the noise right a rock stuck.

1. The rotors are not actually badly heat checked. I checked before the day and i still could not catch anything with a fingernail.

2. As i left the track and heard the noise i stopped and took the wheel off cause i thought something was stuck. Looked and the pads were still about half. I’ll take the pads out today for a better look.

3 i did a thorough look and i don’t think it’s this. With how badly they are grooved the rock would have to been the length of the pad lol

4. I heard this was super unlikely. Which is why I’m a little confused.

The noise is constant and gets so much worse when coming to a slow stop. If the pad is worn down on one end I’ll be very surprised cause i did take time to check them. But I’ll have the pads out at some point today. Yesterday was so hot and exhausting i just slept for 11 hours lol

[N Camarolina]

The sound you describe sounds just like when I had a rock caught against the rotor, but your description of the grooves up and down the rotor surface does not. Frankly I'm not sure what could explain the grooves suddenly happening in that pattern with one day of tracking it.

One other thought: Check to ensure your caliper bolts are tight. If the caliper is moving/pivoting that might explain the odd wear pattern.

After you remove the wheel and pads. If you don't find the culprit, suggest you post a pic of the rotor.

[beworthy3]

Yup, ill pull it apart in a little and post some updates

[beworthy3]

The pads didn’t wear evenly. The bottom is basically gone

[beworthy3]

What the inside of the rotor looks like.

[beworthy3]

So the inside of the rotor looks done to me, the bottom of the pad had no material left so it was metal on metal. I figure the only reason it would happen to this degree is because the pistons are not retracting properly? The top of the pad had close to half material left. My piston seals looked to be starting to crack. I heard before that people do caliper rebuilds. Is it about time for that?

[Kmeleon]

Originally Posted by beworthy3

So the inside of the rotor looks done to me, the bottom of the pad had no material left so it was metal on metal. I figure the only reason it would happen to this degree is because the pistons are not retracting properly? The top of the pad had close to half material left. My piston seals looked to be starting to crack. I heard before that people do caliper rebuilds. Is it about time for that?

This is about normal, when the pads start getting down to say 1/8" before the squealer you really have to be careful and pull the pads to check overall wear. Had similar issues for my state inspection, luckily I pulled the pads from the calipers and found them almost down to metal. Also, when you get lower on the pad they generate more heat as well. Depending on how many sets of pads you've run through the car it might be time for a rebuild.

[DaveC113]

Originally Posted by beworthy3

So the inside of the rotor looks done to me, the bottom of the pad had no material left so it was metal on metal. I figure the only reason it would happen to this degree is because the pistons are not retracting properly? The top of the pad had close to half material left. My piston seals looked to be starting to crack. I heard before that people do caliper rebuilds. Is it about time for that?

Pad taper is very common, and probably worse on oem pods that get too hot. it helps to flip the pads between track days. I also switch between OEM (Ferodo HP1000) for street and autox and Ferodo 3.12 for track. Since both are Ferodo you don't need to rebed the brakes when switching, and once you get it down you can change pads really quickly. The 3.12s are $$$ bot worth it, they last a long time and performance on track is amazing.

I was just looking at rotors, I found DBAs w/o hats for just under $300 each if you don't mind reusing the hats, and $750 for OEM rotors with hats on amazon.

[beworthy3]

Originally Posted by Kmeleon

This is about normal, when the pads start getting down to say 1/8" before the squealer you really have to be careful and pull the pads to check overall wear. Had similar issues for my state inspection, luckily I pulled the pads from the calipers and found them almost down to metal. Also, when you get lower on the pad they generate more heat as well. Depending on how many sets of pads you've run through the car it might be time for a rebuild.

Yeah i was checking the pads. But not as thorough as i should have been. If i looked at the bottom i would have probably noticed this.

This is actually only my 3rd set of pads on the car. I didn’t start tracking until 2022. Original pads were on then. This is now the 3rd set the car has had

[beworthy3]

Caliper position definitely seized up