Do I need new front rotors?

[Clubfoot]

Do you think I need new front rotors. I put new pads on before my first track day. This is what they looked like when I got home. I bought OEM pads and from the beginning they didn't feel like they had the same bite as before. But they still stop the car like before. But now there is a weird vibration and sound when I brake lightly.

 

[Fistpoundin]

always good to turn them. if you can pull them off, most places will only charge like 10 bucks to turn them. you should be good then. remember to set your pads if they are ceramic.

 

[M-Sport fan]

Slotted and/or drilled rotors cannot be turned (unless they came up with some new tech recently which allows this?).

 

[Fistpoundin]

ive turned mine, asked the company that made them, they said they were good to do that. turned out perfect. maybe not the multipiece ones... just my experience.

 

[TyphoonFiST]

Get a Micrometer....measure the rotor..Find the discard spec from the Vendor and go from there.

 

[Quisp]

And at very least use brake clean and sand or scothbrite disc surfaces to get old pad material off.

 

[D1JL]

I am not trying to contradict anyone here or to say who is right or wrong.

For years I professionally did brake jobs and turned rotors every time unless replaced.
This included, drilled, slotted, or any combination there of and never had any issues at all.

Now that I have gotten cheap in my old age I have stopped turning rotors on my own cars at all.
I still replace them when they are too thin or warped but all I do now is just put new pads on.
Again, I know what all the experts say.

Being gentle with the brake in, I have not had any problems.

Once again, I am not saying who is right or wrong, I am just saying that I have done it both ways without issues.

 

[CSM]

You really need to measure the rotors to make sure they are within spec.

I never turn rotors...they are cheap enough just to replace with a quality blank.

 

[maestromaestro]

My view is that if the rotor is “out of spec”, you need to consider changing it. For the OP, it would appear that the pads may not have been bedded properly, so there’s some uneven pad material transfer - which should not be a problem after a while, once the car is stopped from high enough speed.

I am not a fan and generally speaking, neither are the manufacturers, of turning the rotors. These are consumable, and they don’t cost all that much - so need to be discarded if warped or - again - out of spec. That, however, is at times difficult to establish. For instance, my interactions with Wilwood pretty much went nowhere when I asked them if the rotors are OK when the extremely shallow slots are gone. They won’t commit to a thickness, and keep feeding me the same script that I should be the one who determines if the car is “safe to drive”.

So, I replace the rotors annually, along with the pads (in the front). The rear rotors have endured more that 60k miles. The fronts only last for about 22k.

CORRECTION: I only get about 8-9 months or 16k miles from my WW Gt37 rotors/XP8 pads combo.

 

[Intuit]

If the rotors are warped or unevenly worn, you can machine them, but you also need to find out why they did that.

Previous car had no ABS and would routinely warp rotors. So I literally kept two pair and would swap them out between pad changes. One of the set was an expensive rotor and resisted warping for much longer periods. The reason they warped, was due to the caliper slide mounts locking up.

Every place asked about the issue was saying "replace the calipers". But everything aftermarket for the vehicle was complete junk; had learned my lesson several times over not to replace anything OEM unless it was truly bad or failed. (still had OEM calipers when sold at over 327k)

Came up with the solution of honing out the caliper slide-mounts and never had a warping problem since. See "Chronic Rotor Warping" here... https://www.feoa.net/threads/common-problems.64420/#post-614718

ABS or not, it is important to keep them smooth, due to the enhanced propensity for wheel lock-up during heavy braking on wet or icy surfaces. Lock with ABS just means *much* longer stopping distances. When ABS kicks in on some vehicles, the sudden loss of braking force can be startling.