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Old 02-05-2020, 11:42 AM   #1
FC
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Miata grinding noise on braking

The car has developed a sound just like the one you'd if the disks got pretty rusty and you then apply the brakes. Except that this noise does not go away. No sounds at all during coasting, even at low speeds. It only happens with the brakes on. It does not seem to impact braking performance at all either. Also, at times, after driving, it seems to improve, but then it returns.

IIRC, previous owner installed some AutoX-friendly, performance Hawk pads.

I put the car on the lift and pulled the wheels. Visual inspections shows plenty of pad life, and good looking disks. The rears have some uneven radial streaking, but nothing I could attribute the noise to. Unfortunately, the NC has crazy-expansive inner shields, providing a VERY limited view of the inside disc surfaces - particularly in the rear. I could not see rocks or anything like that stick between the discs and shields either.

I figure I can:

1) Remove the pads and better inspect inner disc surfaces and pads.
2) Even if 1) reveals nothing major I could just change the pads (and?) discs.
3) Let it go. This worries me because given the amount of life left and use fo the car, this could be a LONG while.

Any thoughts?
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Old 02-05-2020, 11:59 AM   #2
Nick M3
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Pop the calipers and check. I usually see greater wear on the piston side, so that's worth checking.

If it's good, reassemble and don't worry about it.
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Old 02-05-2020, 02:15 PM   #3
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Not saying this is what your problem is, but I once had something similar when a pad had actually come separated from its backing plate. First glance everything looked fine with plenty of disc life left. When I then pulled the caliper. . . . oops there it is, as the pad fell off
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Old 02-05-2020, 03:21 PM   #4
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Yeah, I have a feeling I have no choice but to pull the pads and check them.
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Old 02-05-2020, 06:10 PM   #5
Nick M3
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Quote:
Originally Posted by FC View Post
Yeah, I have a feeling I have no choice but to pull the pads and check them.
It’s less effort to pull a caliper than popping the wheels off. I hope it’s still on the lift.
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Old 02-05-2020, 10:05 PM   #6
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I pulled the wheels to check it a week ago and have been driving it since. Either way it’s going back up.
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